EE Objectives - PL

At frequency less than the resonant frequency A. series circuit is capacitive and parallel circuit is inductive B. series circuit is inductive and parallel circuit is capacitive C. both circuit are inductive D. both circuit are capacitive

A. series circuit is capacitive and parallel circuit is inductive

The relay in which the measurement is performed by a stationary circuit and which has no moving part is known as A. static relay B. differential relay C. instantaneous relay D. time relay

A. static relay

When the excitation of an unloaded salient pole synchronous motor suddenly gets disconnected A. the motor stops B. it runs as reluctance motor at the speed C. it runs as a reluctance motor at a lower speed D. the motor breaks

A. the motor stops

When the excitation of an unloaded salient pole synchronous motor suddenly gets disconnected, then A. the motor stops B. it runs at the same speed C. it runs at lower speed D. it runs at very high speed

A. the motor stops

Form factor is defined as A. r.m.s value/peak value B. max. value/ r.m.s value C. r.m.s value/average value D. effective value/r.m.s value

C. r.m.s value/average value

The current flowing in the conductors of a dc motor is A. ac B. dc C. ac as well as dc D. transients

A. ac

Which of the following is an active element of a circuit A. ideal current source B. resistance C. inductance D. capacitance

A. ideal current source

The power stated on the name plate of any motor is always A. the output power of the shaft B. the power drawn in KVA C. the power drawn in KW D. the gross power

A. the output power of the shaft

A winding is short pitched by 60 degrees electrical. Its pitch factor is A. 0.5 B. 0.866 C. 0.707 D. 0.966

B. 0.866

For a coil having a span of 2/3 or pole pitch, the coil span factor is A. 0.8 B. 0.866 C. 0.786 D. 0.966

B. 0.866

Relative permeability of material is given by (k is susceptibility of the material) A. 1 + uo*k B. 1 + (k/uo) C. 1 + (uo/k) D. uo*H

B. 1 + (k/uo)

The average dry cell gives an approximate voltage of A. 1.3 V B. 1.5 V C. 1.1 V D. 1 .7 V

B. 1.5 V

If series RC circuit with R=10 ohms and Xc = 10 ohms carries current of 1 ampere effective value the resistor voltage is ____ volts effective and the capacitor voltage is _____ volts effective A. 10*sqrt(2), 10/sqrt(2) B. 10, 10 C. 10*sqrt(2), 10*sqrt(2) D. 5, 10

B. 10, 10

The full load copper loss in a transformer is 400 watts. At half load, the copper loss will be A. 400 watts B. 100 watts C. 200 watts D. 50 watts

B. 100 watts

In a series RC circuit, the voltage across the capacitor and the resistor are 60V and 80V respectively. The input voltage should be A. 70, 45 V B. 100, 37 V C. 105, 42 V D. 108, 60V

B. 100, 37 V

If emf in a circuit is given by e = 100 sin 628t the maximum value of voltage and frequency are A. 100V, 50Hz B. 100V, 100Hz C. 50*sqrt(2) V, 50 Hz D. 50*sqrt(2) V, 100 Hz

B. 100V, 100Hz

The frequency of sinusoidal signal with a period of 4ms is A. 500 Hz B. 250 Hz C. 1 KHz D. 500 KHz

B. 250 Hz

When magnetic flux and the area under its influence are known, the magnetic flux density is given as A. B = OA B. B = O/A C. B = A/O D. B = OA^2

B. B = O/A

The coefficient of self-inductance of a coil is defined as A. NI/O B. NO/I C. O/NI D. OI/N

B. NO/I

In a circuit with a line impedance of 4.5 + j6.5, the maximum power will be transferred when A. ZL = 4.5 + j6.5 B. ZL = 4.5 - j6.5 C. ZL = 6.5 + j4.5 D. ZL = 6.5 - j4.5

B. ZL = 4.5 - j6.5

According to lenz's law the direction of the induced emf and hence current A. may be found by the right hand rule B. always opposes the cause producing it C. it determined by the rate of cutting flux D. none of the above

B. always opposes the cause producing it

The power factor of the arc in circuit breaker is A. always zero B. always unity C. always lagging D. always leading

B. always unity

Local action in the primary cell can be rectified by A. charging the cell B. amalgamating the zinc electrode with mercury C. using the cell for just few minutes D. dry cell

B. amalgamating the zinc electrode with mercury

The maximum voltage that is supplied by an ordinary cell is A. approx. 0.5 V B. approx. 1.5 V C. approx. 1.11 V D. approx. 1.74 V

B. approx. 1.5 V

In High Rupturing Capacity (HRC) fuse, the time between cut-off and final current zero is known as A. total opening time B. arcing time C. pre-arcing time D. any of the above

B. arcing time

Capacitors are said to A. block ac and pass dc B. block dc and pass ac C. pass ac and dc D. block ac and dc

B. block dc and pass ac

The advantage of ring main system is A. less voltage drop in the feeder B. continuity of supply to feeding point C. less costly D. none of the above

B. continuity of supply to feeding point

Meter accuracy is determined by A. half-scale deflection B. full-scale deflection C. one fourth of full-scale deflection D. one-tenth of full-scale deflection

B. full-scale deflection

To reduce the effect of a voltmeter upon the circuit under test, we should A. decrease the multiplier resistance B. get an Instrument with a higher internal resistance C. use a parallel resistor D. use an a.c. meter with rectifier

B. get an Instrument with a higher internal resistance

The advantage of the iron-nickel battery over the lead-acid battery is that A. it has a much higher efficiency B. it needs less maintenance C. the cell voltage of the iron-nickel battery is higher D. It is much cheaper

B. it needs less maintenance

Presence of ozone as a result of corona is harmful because A. it gives bad odor B. it transfers energy to the ground C. reduces power factor D. it corrodes the material

B. it transfers energy to the ground

If the moving-iron type ammeter is connected to a circuit, and we Interchanged its connection, then A. it will give no deflection B. its reading will not change C. it will deflect in the opposite direction D. it will burn out

B. its reading will not change

The time constant of an inductive circuit is defined as the ratio of A. R/L B. Rt/L C. Lt/R D. L/R

D. L/R

For extra high voltage lines, which circuit breaker is preferred A. bulk oil circuit breaker B. vacuum circuit breaker C. SF6 gas circuit breaker D. Minimum oil circuit breaker

D. Minimum oil circuit breaker

Voltage applied across a circuit acts as A. mass of electrons B. negative ions C. component of current D. a force

D. a force

Polar curve of a filament lamp A. shows the distribution of illumination in all directions B. shows the luminous Intensity in all directions in one plane around a light source C. determines the efficiency of the lamps D. gives the effectiveness of the reflector used for a lamp

B. shows the luminous Intensity in all directions in one plane around a light source

Steam-turbo-alternators are much smaller in size than water-turbine alternators for a given output. This is so because A. steam-turbo alternators are built with smaller capacities B. steam-turbo alternators run at high speed C. steam-turbo alternators have long rotors D. all of these

B. steam-turbo alternators run at high speed

The ampere hour capacity of battery depends on A. the thickness of the plates B. the area of the plates C. the strength of the electrolytes D. the distance between the plates

B. the area of the plates

The output power of any electrical motor is taken from A. the armature B. the coupling mounted on the shaft C. the conductors D. the poles

B. the coupling mounted on the shaft

The direction of rotation of a dc series motor can be reverse by interchanging A. the supply terminals only B. the field terminals only C. the supply as well as field terminals D. none of these

B. the field terminals only

The field flux of a dc motor can be controlled to achieve A. the speeds lower than rated speed B. the speed higher than rated speed C. the speed at rated speed D. none of these

B. the speed higher than rated speed

A series motor is started without load. The effect is that A. the torque increase rapidly B. the speed increase rapidly C. the current drawn increase rapidly D. the back emf decrease

B. the speed increase rapidly

While comparing magnetic and electric circuits, the flux of magnetic circuit is compared with which parameter of electric circuit? A. emf B. current density C. conductivity D. current

D. current

If the field of a dc shunt motor is opened A. it will continue to run at its rated speed B. the speed of the motor will become very high C. the motor will stop D. the speed of the motor will decrease

B. the speed of the motor will become very high

The function of moderator in nuclear reaction is A. to accelerate the reaction B. to control the reaction C. to absorbed excessive neutrons D. to liberate excessive neutrons

B. to control the reaction

One of the reasons for improving the power factor is A. to increase the reactive power B. to decrease the reactive power C. to increase the real power D. to effectively reduce consumption

B. to decrease the reactive power

The maximum power developed in a synchronous motor occurs at a coupling angle of A. 0 B. 45 C. 90 D. 180

C. 90

Whenever a conductor cuts magnetic flux, an emf is induced in that conductor. The above statement is due to A. Joule's law B. Coulomb's law C. Faraday's law D. Weber and Ewing's theory

C. Faraday's law

A circuit component that opposes the change in the circuit voltage is A. resistance B. inductance C. capacitance D. none of the above

C. capacitance

Alternators are usually designed to generate A. variable frequency B. definite currents C. definite frequencies D. definite power factor

C. definite frequencies

In star connected system, the line current is A. 0.707 times the phase current B. 1.732 times the phase current C. equal to the phase current D. 1.414 times the phase current.

C. equal to the phase current

To a series RLC circuit, a voltage of 10 V is applied. If Q of the coil at resonant frequency is 20, the voltage across the inductor at resonant frequency will be A. 200 V B. 100 V C. 75 V D. 50 V

A. 200 V

Wooden poles for supporting transmission lines are used for voltage up to A. 22 kV B. 440 kV C. 11 kV D. 66 kV

A. 22 kV

The work done by an external agent to turn the dipole from the position of p=0 to p=180 is A. 2aqE B. zero C. aqE D. (aqE)/2

A. 2aqE

An ideal current source has zero A. voltage on no load B. internal resistance C. internal conductance D. internal inductance

C. internal conductance

MHO Relay is used for A. rectifier B. circuit breaker C. transmission lines D. feeders

C. transmission lines

The internal resistance of a discharged battery A. is more B. is less C. remains the same D. is negative

A. is more

The current in RLC circuit at resonance is A. maximum B. minimum C. infinity D. zero

A. maximum

The current drawn by the line due to corona is A. non-sinusoidal B. sinusoidal C. square D. none of these

A. non-sinusoidal

The type of the motor that does not have a commutator is the A. repulsion motor B. induction motor C. DC shunt motor D. AC series motor

A. repulsion motor

As the force on the contacts is increased, the contact resistance will A. increase linearly B. increase exponentially C. remain unaltered D. decrease

D. decrease

The specific resistance is defined as A. resistance of the conductor which has a length of 1 m and cross-sectional area of 1 m2 at 25 deg C B. resistance of any conductor at 25 deg C C. resistance of any conductor at 20 deg C D. resistance of a conductor which has a length of 1 m and a cross-section at 1 cm2 at 25 deg C

A. resistance of the conductor which has a length of 1 m and cross-sectional area of 1 m2 at 25 deg C

In a series circuit consisting of resistance and reactance, power factor is defined as the ratio of A. resistance to impedance B. resistance to reactance C. reactance to impedance D. resistance to resistance

A. resistance to impedance

The phase angle for a series RC circuit may be computed as the angle between the ______ and ______ phasors A. resistance, impedance B. resistance, reactance C. reactance, impedance D. none of these

A. resistance, impedance

The direction of rotation of a de motor is reverse by A. reversing armature connection B. interchanging the armature and field connection C. adding resistance to the field circuit D. reversing supply connection

A. reversing armature connection

The standard practice nowadays in alternators is to have A. rotating field B. rotating armature C. either rotating field or rotating armature D. none of the above

A. rotating field

The field F = yi +xj is a A. rotational field B. irrotational field C. conservative field D. static electric field

A. rotational field

What kind of rotor is most suitable for turbo-alternators which are designed to run at high speed A. salient pole type B. non-salient pole type C. both a and b D. none of the above

A. salient pole type

What classification if given to a d c generator that receives its field excitation current from internal source? A. self-excited excitation B. controlled excitation C. separately excited D. internally excited

A. self-excited excitation

Ferromagnetic materials generally behave as a A. semi-conductor B. conductor C. insulator D. any of the above

A. semi-conductor

The power transmitted will be maximum when A. sending end voltage is more B. receiving end voltage is more C. reactance is high D. corona losses are least

A. sending end voltage is more

Inlerpotes are connected in _____ with the armature and compensating windings are connected in ______ with the armature A. series, series B. shunt, series C. series, shunt D. shunt, shunt

A. series, series

Secondary cell can produce large amounts of power for a A. short time and can be recharged B. long time and can be recharged C. short time and cannot be recharged D. long time and cannot be recharged

A. short time and can be recharged

DC generators preferred for charging automobile batteries is A. shunt generator B. series generator C. long shunt compound generator D. short shunt compound generator

A. shunt generator

Which of the following is most suitable for running in parallel operations A. shunt generator B. series generator C. compound generator D. all of these are equally suitable

A. shunt generator

Squirrel cage induction motor differs from the slip ring type in that it has no A. slip rings B. rotor windings C. windings on the stator D. rotating part

A. slip rings

The diameter of high speed turbo alternators as compared to hydroelectric ones are A. smaller because speed is high B. smaller because speed is less C. larger because speed is high D. none of these

A. smaller because speed is high

The magnetic materials which can be easily magnetized in the directions are known as A. soft magnetic materials B. hard magnetic materials C. low hysteresis loss materials D. high hysteresis loss materials

A. soft magnetic materials

Skin effect of proportional to A. square of diameter of conductor B. diameter of conductor C. cube of diameter of conductor D. square root of diameter of conductor

A. square of diameter of conductor

A diesel power plant is best suited as A. stand by plant B. base load plant C. peak load plant D. general purpose plant

A. stand by plant

Charging a lead-acid causes the electrolyte to become A. stronger B. stable C. weaker D. water

A. stronger

Merz-price protection Is used on A. substation B. capacitor banks C. induction motor D. generators

A. substation

Power factor improvement may be achieved by the use of A. synchronous motor B. induction motor C. long transmission lines D. reducing reactive power

A. synchronous motor

A collapsing field around a coil A. tends to oppose the decay of coil current B. helps the decay of the coil current C. tends to aid current flow reversal D. does not affect the current coil

A. tends to oppose the decay of coil current

In moving coil meters, damping Is provided by A. the aluminum frame B. damping vane C. damping vane in an air tight chamber D. none of these

A. the aluminum frame

In a synchronous motor, the torque angle is A. the angle between the rotating stator flux and rotor poles B. the angle between the magnetizing current and back emf C. the angle between the supply voltage and the back emf D. none of the above

A. the angle between the rotating stator flux and rotor poles

The coupling coefficient denotes A. the degree of magnetic linkage B. whether the reluctance remains constants C. the variation of the inductance between the two coils D. whether the flux linkage is constant

A. the degree of magnetic linkage

Armature reaction is attributed to A. the effect of the magnetic field set-up by the armature current B. the effect of the magnetic field set-up by field current C. copper loss in the armature D. the effect of the magnetic field set-up by back emf

A. the effect of the magnetic field set-up by the armature current

The transformer of energy from primary of the transformer to secondary takes place due to A. the flux linkage between the two windings B. the difference in number of turns of primary and secondary windings C. the changing current in two windings D. none of these

A. the flux linkage between the two windings

A 3 phase synchronous motor is running clockwise. In case the direction of its field current is reversed A. the motor will continue to run in the same direction B. the motor will run at reverse direction C. the motor will stop D. the winding of the motor will burn

A. the motor will continue to run in the same direction

A 3 phase, 400 V, 50 Hz salient pole synchronous motor is running on no load. If there is break in the excitation winding of the motor A. the motor will stop B. the winding will get overheated C. the motor will run as reluctance motor at the rated rpm D. the motor will run as reluctance motor at lower rpm

A. the motor will stop

Mark the correct statement A. the percentage of resistance, reactance and impedance have the same value whether referred to primary or secondary of the transformer B. A good transformer must have regulation as high as possible C. If the power lector is leading the regulation of a good transformer will be higher than when it is lagging D. none of the above is correct

A. the percentage of resistance, reactance and impedance have the same value whether referred to primary or secondary of the transformer

In a balanced three phase star connected system, the line voltage is A. the phasor difference of two phase voltages B. the phasor sum of two phase voltages C. 0.707 times the phase voltage D. 1.414 times the phase voltage

A. the phasor difference of two phase voltages

If the input to the prime mover of an alternator is kept constant but the excitation is changed then A. the reactive component of the output is changed B. the active component of the output is changed C. the pf of the load remains constant D. the alternator speed will vary

A. the reactive component of the output is changed

If we increase the flux density in the case of a transformer A. the size of the transformer will reduce B. the distortion in the wave shape will reduce C. the hysteresis and eddy current losses will reduce D. none of the above is true

A. the size of the transformer will reduce

It was experimentally found by James Prescott Joule that the heat produced in a current carrying conductor is proportional to A. the square of current B. square of resistance C. the current D. inversely proportional to time

A. the square of current

For a 3-phase wound rotor induction motor, as increase In rotor resistance affects the motor performance in the following way A. the starting current decreases B. the motor efficiency decreases C. the maximum torque is reduced D. the speed increases

A. the starting current decreases

The self-induced of the coil is not influenced by A. the voltage applied of the coil B. the charge in current C. number of turns of the coil D. magnetic resistance of the magnetic circuit

A. the voltage applied of the coil

For open circuited condition of Thevenin's theorem all sources of emf in the network are replaced by A. their internal impedance B. their internal resistance C. as total a big source of emf D. none of the above

A. their internal impedance

Among all the ac systems, the most superior system is the A. three phase, three wire with maximum voltage between conductors B. three phase, three wire with maximum voltage between conductors and earth C. three phase, three wire with rms voltage between conductors D. three phase, three wire with rms voltage between conductors and earth

A. three phase, three wire with maximum voltage between conductors

Another reason for improving the power factor is A. to avoid poor voltage regulation B. to keep voltage regulation constant C. to increase the voltage regulation D. to accomplish ideal regulation

A. to avoid poor voltage regulation

In the electric field, the potential is the work done in Joules A. to bring positive charge of 1 coulomb from infinity to that point B. to bring any charge from infinity to that point C. in moving a unit positive charge from one point to another point D. any of these

A. to bring positive charge of 1 coulomb from infinity to that point

Why is the air gap between the stator and armature of an electric motor keep as a small as possible? A. to get a stronger magnetic field B. to make the rotation easier C. to reach a higher speed of rotation D. to improve the air calculation

A. to get a stronger magnetic field

When the current flows through heater coil it glows but supply wiring does not glow because A. supply wiring is covered by insulation layer B. current through supply line flows at slower speed C. supply wires are made of superior material D. resistance of heater coil is more than the supply wire

D. resistance of heater coil is more than the supply wire

For a three phase unbalanced load A. the power factor of each phase is proportional to the load B. the power factor of each phase will be the same C. the power factor of at least one of the phases must be leading D. the power factor of each phase may be different

D. the power factor of each phase may be different

A network is said to be non-linear if it does not satisfy A. homogeneity condition B. superposition condition C. both a and b D. associative condition Which of the following statement is not correct? A. ideal voltage source is one whose internal conductance is zero B. ideal current source is one whose internal conductance is zero C. ideal voltage source is one whose internal resistance is zero D. all of these

A. ideal voltage source is one whose internal conductance is zero

Temperature coefficient of a conductor is defined as the A. increase in resistance per ohm per degree centigrade B. increase in resistance per degree centigrade C. increase in resistance per degree absolute D. decrease in resistance per ohm per degree centigrade

A. increase in resistance per ohm per degree centigrade

As compared to an amplifier a transformer cannot A. increase output power B. increase the output current C. increase the output voltage D. none of these

A. increase output power

Dampers in large generators A. increase stability B. reduce voltage fluctuations C. reduce frequency fluctuations D. none of the above

A. increase stability

If a speed of dc shunt motor increases, the back emf A. increases B. remains constant C. decreases and then increases D. decreases

A. increases

The resistance of the carbon when its filament temperature is decreased A. increases B. decreases C. remains the same D. increase enormously

A. increases

In 3 phase induction motor the torque A. increases with the increase in supply voltage B. decreases with the increase in supply voltage C. has no relation with the supply voltage D. a and b depending upon situation

A. increases with the increase in supply voltage

An alternator is capable in delivering power at a particular frequency. The frequency can be increased by A. increasing the armature speed B. reversing the armature rotation C. increasing the current supplied to the field electromagnets. D. reversing the field polarity

A. increasing the armature speed

The magnetic flux in the magnetic circuit can be increased by A. increasing the mmf B. decreasing the mmf C. reversing the direction of current D. making an air gap in the core

A. increasing the mmf

In the impedance triangle the inductive reactance and impedance phasor are analogous to the ____ and phasor respectively in the voltage triangle A. inductive voltage, total voltage B. inductive current, total current C. inductive voltage, resistive voltage D. inductive current, resistive current

A. inductive voltage, total voltage

If a flux of a dc motor approaches zero, its speed will approach A. infinity B. zero C. a stable value nearer to the rated speed D. none of these

A. infinity

The purpose of the grid system is to A. interconnect the power stations B. supply energy to remote areas C. make extra high voltage available to consumers D. make distribution of energy at reasonable cost

A. interconnect the power stations

A fuse wire possesses a A. inverse time characteristics B. direct time characteristics C. neither of the above D. none of the above

A. inverse time characteristics

The movable wire is moved to the east causing an induced current I due to north. The direction of magnetic field B. in a region should be A. inward the plane of paper B. outward the plane of paper C. opposite to the velocity vector D. in the direction of the current

A. inward the plane of paper

The function of the depolarizer in carbon zinc cell is that A. it converts the produced hydrogen into water B. it prevents the fast chemical action on the zinc container C. it synthesizes the decomposed electrolyte D. it absorbs the oxygen produced in the cell

A. it converts the produced hydrogen into water

What will happen to an insulating medium voltage more than the breakdown voltage is applied or A. it will get punctured B. it will become magnetic C. it will melt D. its molecular structure will change

A. it will get punctured

Wet cell is preferred to a dry cell because A. its corrosion is small B. its internal resistance is high C. it polarizes continuously D. it has higher emf

A. its corrosion is small

Which of the following is a correct statement about a series motor? A. its field winding consists of a thicker wire and less turns B. it can run easily without load C. it has almost constant speed D. it has a poor torque

A. its field winding consists of a thicker wire and less turns

Resistance of the conductor increases when A. its length increases B. its area decreases C. Both are and length increases D. specific resistance is kept constant

A. its length increases

The efficiency of any electrical machine apparatus will be high, if A. its losses are minimum B. its losses are more C. voltage applied is constant D. the current drawn are minimum

A. its losses are minimum

If field of a synchronous motor is under-excited the power factor will be A. lagging B. leading C. unity D. more than unity

A. lagging

In a series RL circuit, the inductor current ______ the resistor current A. lags B. leads C. is equal D. is negative

A. lags

An alternator s said to be over-excited if it operating at A. leading pf B. lagging pf C. unity pf D. zero voltage regulation

A. leading pf

The reactance of a transformer is determined by its A. leakage flux B. common core flux C. size of the core D. permeability of the material of the core

A. leakage flux

Internal heating of capacitor is usually attributed to A. leakage resistance B. electron movement C. plate vibration D. dielectric charge

A. leakage resistance

The law that induces emf and current always opposes the cause producing them was discovered by A. lenz B. faraday C. Maxwell D. ohm

A. lenz

The shunt resistance in an ammeter is usually A. less than meter resistance B. equal to meter resistance C. greater than meter resistance D. of any value

A. less than meter resistance

Various dc and ac systems of transmission are available but to find out which system is superior, comparison is made on the basis of equal A. line loss B. voltage drop C. percentage voltage drop D. power transmitted

A. line loss

The superposition theorem is applicable to A. linear response only B. linear and non-linear response only C. linear, non-linear and time variant response D. any circuits that shows complexity

A. linear response only

A load curve is a plot of A. load vs time B. load vs cost of power C. load vs current D. load vs generation capacity

A. load vs time

A closed path made of several branches of the network is known as A. loop B. junction C. branch D. star

A. loop

It is difficult to magnetize steel because it is A. low permeability B. higher retentivity C. high permeability D. high density

A. low permeability

The path of the magnetic flux in the transformer has A. low reactance B. high reactance C. high conductivity D. low resistance

A. low reactance

Brushes are always placed along A. magnetic neutral axis (MNA) B. Geometric neutral axis (GNA) C. perpendicular to MNA D. perpendicular to GNA

A. magnetic neutral axis (MNA)

In an RLC circuits, the current al resonance is A. maximum B. minimum C. Infinity D. zero

A. maximum

Which of the following is a primary cell A. mercury oxide B. lead acid c C. nickel-iron-alkaline D. nickel-cadmium- alkaline

A. mercury oxide

In RLC circuits, the current at resonance is A. minimum in parallel circuit and maximum in series circuit B. maximum in parallel circuit and minimum in series circuit C. maximum in both the circuits D. minimum in both the circuits

A. minimum in parallel circuit and maximum in series circuit

For a given loading, it is better to feed radial distributor at both ends as this gives A. minimum loss and voltage drop B. greater cross sectional area of the conductor and minimum loss C. continuity of supply and greater cross sectional area of conductor D. all of these

A. minimum loss and voltage drop

Fusing factor for HRC fuse is A. minimum-fusing-current current rating B. minimum-fusing-current minimum rupturing time C. maximum-fusing-current minimum fusing current D. minimum fusing current protective current of a circuit

A. minimum-fusing-current current rating

Megger in its operation Is based upon A. moving-coil meter B. moving-iron meter C. dynamic-meter meter D. electrostatic meter

A. moving-coil meter

For synchronizing three phase alternators, the additional requirement is that the phase rotation A. must be the same B. is clockwise C. is anti-clockwise D. none of the above

A. must be the same

The function of an interpole is A. neutralize cross field of armature reaction and obtain Ideal commutation B. increase the armature reaction and thus obtain ideal commutation C. neutralize cross field of armature and thus obtain under commutation D. supports the operation of the armature

A. neutralize cross field of armature reaction and obtain Ideal commutation

The greatest economy of conductor material is possible by adopting a dc system of transmission, particularly when the power factor of the ac system is considerable less than unity. The factor which limit the dc transmission is A. no easy way of obtaining high voltage B. high voltage drop C. that dc resistance is higher than ac resistance D. that rms voltage is not available

A. no easy way of obtaining high voltage

Intelpoles are normally connected in A. parallel with the field B. in series with the field C. parallel with the load D. series with the load

A. parallel with the field

Interaction between the neighbouring dipoles is neglible in the case of a A. paramagnetic materials B. diamagnetic materials C. antiferromagnetic material D. ferromagnetic material

A. paramagnetic materials

A gas turbine power plant usually suits for A. peak load operation B. base load operation C. casual run D. none of the above

A. peak load operation

The greatest value attained during one half of the cycle is called the A. peak value B. average value C. r.m.s. value D. deflective value

A. peak value

When using any instrument for measurement and testing of an electrical circuit, your ____ should be considered A. personal safety B. theoretical knowledge C. surrounding D. dress

A. personal safety

Distilled or approved water is used in electrolyte because it A. prevents or slows down local action B. speeds up electrochemical action C. improves specific gravity D. prevents polarization

A. prevents or slows down local action

No load primary input is practically equal to the iron losses in the transformer because A. primary current is small B. secondary current is small C. both the currents are small D. no load input is not equal to iron losses

A. primary current is small

For a power plant, the expenditure on which of the following item is expected to be negligible A. publicity B. taxes C. wages D. insurance

A. publicity

Power plant using coal work closely on which of the following cycle A. rankine cycle B. binary vapor cycle C. Otto cycle D. Brayton cycle

A. rankine cycle

The size of a transformer core will depend on A. frequency B. flux density of the core material C. area of the core D. a and b both Two transformers operating in parallel will share the load depending upon their A. rating B. leakage reactance C. efficiency D. per unit impedance

A. rating

The difference between the synchronous speed Ns and the actual speed N of the rotor is known as slip. II can be expressed as a percentage and is given by A. %S = (Ns-N)/Ns x 100 B. %S =(N-Ns)/N x 100 C. %S = (N-Ns)/Ns x 100 D. %S = (Ns-S)

A. %S = (Ns-N)/Ns x 100

A cylinder of radius r is immersed in a uniform Es. The cylinder axis is parallel to the field going to the right. The flux for the surface is A. - E*pi*r^2 B. zero C. E*pi*r^2 D. -2*E*pi*r

A. - E*pi*r^2

For an RL circuit, the power factor cannot be less than or greater than A. 0,1 B. 1,0 C. 0, -1 D. -1. 0

A. 0,1

In a 3-phase synchronous converter the ratio of ac current to dc current is equal to A. 0.943 B. 0.612 C. 1.60 D. 0.954

A. 0.943

Which of the following frequencies has the longest period? A. 1 Hz B. 10 Hz C. 1 KHz D. 100 KHz

A. 1 Hz

The no-load current of a transformer in terms of full load current is usually A. 1 to 3% B. 3 lo 9% C. 9 to 12% D. 12 to 20%

A. 1 to 3%

With DC generator which of the following regulation is preferred A. 1% regulation B. 50% regulation C. infinite regulation D. 100% regulation

A. 1% regulation

The lead acid accumulator should be recharged when the specific gravity of the electrolyte is about A. 1.15 B. 1.25 C. 1.80 D. 1.35

A. 1.15

Power in a three phase delta system with balanced load is equal to A. 1.732 x VL x IL x power factor B. 1.732 x Vph x Iph x power factor C. 3 x Vph x IL x power factor D. 3 x VL x IL x power factor

A. 1.732 x VL x IL x power factor

When a H.V. ac circuit breaker Is tested for endurance, it is tested for at least A. 1000 opening-closing operations B. 100 opening-closing operations C. 10 opening-closing operations D. 5 opening-closing operations

A. 1000 opening-closing operations

Four condenser of 4 uf each are connected in parallel. Their equivalent capacitance will be A. 16 uf B. 64 uf C. 4 uf D. 1 uf

A. 16 uf

Overall thermal efficiency of the steam power station is in the range A. 18 to 24 % B. 30 to 40% C. 44 to 62% D. 68 to 79%

A. 18 to 24 %

The primary and the secondary voltages are A. 180 out of phase in a transformer B. always in phase in a transformer C. 90 out of phase in a transformer D. 30 or 60 out of phase in a transformer

A. 180 out of phase in a transformer

The resistance R1 and R2 are connected in parallel. The ratio of the value of the resistance R1:R2 is 4:1. The currents in R1:R2 will be equal to A. 1:4 B. 1:1 C. 4:1 D. 4:4

A. 1:4

The number of cycle in which a high speed circuit breaker can complete its operation is A. 3 to 8 B. 20 to 30 C. 10 to 18 D. 40 to 50

A. 3 to 8

The exact natural frequency of free oscillations in an oscillatory circuit with capacitance of 0.055 uf, inductance 2 uH and resistance 1 ohm will be A. 478 kHz B. 337kHz C. 272 kHz D. 192 kHz

A. 478 kHz

A 5 ohms resistor and an inductor of 0.025 henry connected in series with an effective voltage supply of 10V. The effective value of the resistor voltage is _____ volts A. 5*sqrt(2) B.5 C. 5/sqrt(2) D. 10

A. 5*sqrt(2)

A pelton wheel is A. Axial flow Impulse turbine B. Inward flow reaction turbine C. Outward flow impulse turbine D. Inward flow impulse turbine

A. Axial flow Impulse turbine

The relative permeability is given by A. B/(u x H) B. B/H C. uo/u D. uo/H

A. B/(u x H)

Damping provides A. Braking action on a meter pointer B. Good accuracy C. Starting torque on the meter pointer D. Counter torque to deflection torque

A. Braking action on a meter pointer

Which of the following relays Is used on transformer A. Buchholz relay B. MHO relay C. Merz-price relay D. None of these

A. Buchholz relay

One of the line parameters which is neglected in short transmission line is A. Capacitance B. inductance C. Admittance D. Resistance

A. Capacitance

What is the relation between the field strength E, voltage V and distance between the parallel plates A. E = V/d B. E = Vd^2 C. E = Vd D. E = V^2/d

A. E = V/d

When (n) cells each of emf (E) volts and internal resistance (r) ohms are connected in parallel, the strength of the current is given by A. E/(R + r/n) B. nE/(r + R) C. E/(n + Rr) D. E/(R + n/r)

A. E/(R + r/n)

In a parallel plate capacitor of capacitance Co the electric field is E. If a dielectric slab with dielectric constant equal to 7 is introduced to fill capacitor completely, the electric field will become A. E/7 B. E C. E/3.5 D. 7E

A. E/7

The sinusoidal voltage developed per pole per phase in a group of coils is defined as A. Eg = 4.44 Onf KdKp V B. Eg = 4.44 On KdKp V C. Eg = 4.4 ONKp V D. none of these

A. Eg = 4.44 Onf KdKp V

For the same original network end load, Thevenin's and Norton's equivalent circuits are related by A. Eth = In Zth= ln Zn B. Zn = Eth/Ith C. Eth = Ith Zth = Ith Zth D. Zth = En/In

A. Eth = In Zth= ln Zn

Three elements having conductance G1, G2, and G3 are connected in parallel. Their combined conductance will be a A. G1 + G2 + G3 B. (G1G2 + G2G3 + G3G1)/(G1 + G2 + G3) C. 1/(G1 + G2 + G3) D. 1/ (1/G1 + 1/G2 + 1/G3)

A. G1 + G2 + G3

Which of the following plants will take least time in starting from cold condition to full load condition A. Gas turbine B. Steam turbine C. Nuclear Power Plant D. Hydro-electric plant

A. Gas turbine

Out of the following, select the best conductor of electricity A. Graphite B. China clay C. Porcelain D. None of these

A. Graphite

The area of hysteresis loop represents hysteresis material is proportional to A. J/m3/s B. J/cycle C. J/s D. J-s

A. J/m3/s

For low head and high discharge, the hydraulic turbine used is A. Kaplan turbine B. Francis Turbine C. Pelton turbine D. Jonval turbine

A. Kaplan turbine

The concentric windings are used on the core type transformers with A. LT winding placed next to core B. HT winding placed next to core C. LT winding on the outer side D. HT winding on the outer side

A. LT winding placed next to core

The illumination at a point of a surface is the luminous flux per unit area of the surface and its unit is A. Lux B. lumen C. Candle power D. candela

A. Lux

Mutual inductance can also be defined as A. M = N2 dO/dt B. M = N2 dt/di C. M = N2 dI/dt D. M = N2 dL/dt

A. M = N2 dO/dt

Which of the following acts as depolarizer in dry cell? A. Manganese dioxide B. Zinc chloride C. Ammonium chloride D. Cartoon powder

A. Manganese dioxide

Which of the following bridge is used to measure inductance of low Q inductor? A. Maxwell bridge B. Hay bridge C. Wein bridge D. Anderson bridge

A. Maxwell bridge

Megger essentially is a A. Megohmmeter B. Shunt-type ohmmeter C. Series type ohmmeter D. Dynamometer

A. Megohmmeter

Regarding Norton's equivalent, which of the following is not correct? A. Norton's equivalent is the voltage equivalent of the network B. Norton's equivalent is the current equivalent of the network C. Norton's equivalent resistance is the same as the Thevenin's equivalent resistance D. The load is connected in parallel to the Norton equivalent resistance and Norton's equivalent source

A. Norton's equivalent is the voltage equivalent of the network

Frequency of the rotor current in an induction motor in terms of Ns, N and P is given as A. Ns - N = 120f'/P B. Ns - N = 120P/f' C.Ns = 120/Pf' D. none of the above

A. Ns - N = 120f'/P

A Francis Turbine is A. Outward flow impulse turbine B. Outward flow reaction turbine C. Inward flow impulse turbine D. Inward flow reaction turbine

A. Outward flow impulse turbine

The fact that the conductor carries more current on the surface of core is known as A. Permeability B. Unsymmetrical C. Corona D. skin effect

A. Permeability

A capacitance C is charged through resistance R. The time constant of the charging circuit is given by A. RC B. 1/RC C. C/R D. R/C

A. RC

If Rs is the resistance of secondary winding of the transformer and K is the transformation ratio then the equivalent secondary resistance referred to primary side will be A. Rs/K^2 B. Rs/K C. Rs/K^3 D Rs/sqrt(K)

A. Rs/K^2

Major share of power produced in the Philippines is through A. Thermal power plant B. Diesel power plant C. Nuclear Power Plant D. Hydroelectric Power plant

A. Thermal power plant

What is the minimum number of wattmeters required to measure unbalanced power of a three phase system A. Two B. four C. three D. one

A. Two

Which of the following is not a secondary nuclear fuel A. U-235 B. U-233 C. Plutonium D. Pn-239

A. U-235

Voltage equation for dc motor is A. V = Eb+laRa B. V = Eb-laRa C. Eb = V+IaRa D. Eb = laRa

A. V = Eb+laRa

If Xs= the synchronous reactance of the machine. Xe= leakeage reactance and Xa = reactance due to armature flux then A. Xa = Xs - Xe B. Xa = Xs + Xe C. Xa = Xe - Xs D. Xe = XaXs

A. Xa = Xs - Xe

International ohm is defined in terms of resistance of A. a column of mercury B. a cube of carbon C. unit length of metal wire D. a cube of copper

A. a column of mercury

Eddy current losses in a transformer are minimized by laminating the core, the laminations being insulated from each other by A. a light coat of core plate varnish B. thin sheets of mica C. thick paper insulation D. any one of the above

A. a light coat of core plate varnish

It is not easy to find the value of impedance in parallel circuit but power factor can be easily obtained as the ratio of A. active current to line current B. reactive current to line current C. line current to active current D. line current to reactive current

A. active current to line current

In a radio, a gang condenser is a type of A. air capacitor B. paper capacitor C. ceramic capacitor D. electrolytic capacitor

A. air capacitor

What type of core is used for a high frequency transformer? A. air core B. closed iron core C. aluminum core D. open iron core

A. air core

Conservator consist of A. an air-tight metal drum fixed at the top of the tank B. drum placed at the bottom of the tank C. overload protection D. none of these

A. an air-tight metal drum fixed at the top of the tank

Preferably, the resistance between the primary and the secondary of a transformer should be A. as low as possible B. as high as possible C. low or high depending upon whether it is step up or step down respectively D. high or low depending upon whether It is step up or step down respectively

A. as low as possible

Heating value of coal largely depends on A. ash content B. moisture content C. volatile matter D. size of coal particle

A. ash content

Load Factor during a period is A. average load/maximum load B. maximum load/installed capacity C. average load/installed capacity D. maximum load/average load

A. average load/maximum load

Two wattmeters can be used to measure 3-phase power for a A. balanced and unbalanced load B. unbalanced load only C. balanced load only D. unity power factor only

A. balanced and unbalanced load

A nuclear power plant Is invariable used as a A. base load plant B. peak load plant C. stand by plant D. spinning reserve plant

A. base load plant

Three resistances R1, R2, and R3 are connected in series with a 220 V supply. If R2 becomes open-circuited the reading of the voltmeter will A. becomes 220 V B. decrease slightly C. falls to zero D. increase slightly

A. becomes 220 V

Many industrial tariffs penalize consumers whose power factor falls A. below 0.8 B. below unity C. between 0.8 and 0.95 D. below 0.35

A. below 0.8

The relationship between voltage and current is the same for two opposite directions of current in case of A. bilateral network B. active network C. unilateral network D. passive network

A. bilateral network

In a steam power plant which component needs maximum maintenance attention A. boiler B. condenser C. turbine D. water treatment plant

A. boiler

Series reactors are installed at strategic locations of power system to A. bring down the fault level within the capacity of the switchgear B. directly pass the fault surges to ground C. pass neutralizing surges of opposite nature D. discharge the capacitor

A. bring down the fault level within the capacity of the switchgear

The function of a shunt in an ammeter is to A. bypass the current B. Increase the current in the coil C. decrease the voltage drop D. increase the meter resistance

A. bypass the current

One advantage of a secondary cell is that it A. can be recharged B. can be used for portable equipment C. it is compact, easy to carry D. cannot be recharged

A. can be recharged

Schering bridge can be used to measure A. capacitance and its power factor B. Q of the coil C. Inductance and its Q value d. Very small resistance D. very small resistance

A. capacitance and its power factor

Gassing occurs in the process of A. charging an accumulator B. charging a dry cell C. discharging an accumulator D. discharging a dry cell

A. charging an accumulator

Equalizer connection are required when paralleling two A. compound generator B. series generator C. shunt generator D. alternators

A. compound generator

Air standard efficiency of a diesel engine depends on A. compression ratio B. speed C. fuel D. torque

A. compression ratio

Permeance is analogous to A. conductance B. resistance C. reluctance D. none of these

A. conductance

In a series circuit the current is A. constant B. zero always C. proportional to the resistance D. different in different resistors

A. constant

Synchronous motor has A. constant speed B. slight drop in speed on full load C. high speed at low torque D. low speed at high torque

A. constant speed

Which toss in the dc generator varies with the load A. copper loss B. eddy current loss C. hysteresis loss D. windage loss

A. copper loss

With the measurement terminals open circuited, the infinity reading of a megger is due to A. current in the coil connected across the measurement points B. unit in the coil connected across the generator C. current in both coils D. zero deflection of the pointer

A. current in the coil connected across the measurement points

A fuse is normally A. current limiting device B. voltage limiting device C. power limiting device D. power factor correcting device

A. current limiting device

In the commutation process it is the A. current which is getting reversed B. voltage which is getting reversed C. both of these D. none of these

A. current which is getting reversed

If a dielectric is placed in an electric field, the field strength A. decreases B. increases C. remains the same D. becomes zero

A. decreases

The use of higher flux density in transformer design A. decreases the weight per KVA B. increases the weight per KVA C. increases the weight per KW D. decreases the weight per KW

A. decreases the weight per KVA

Just like a dc shunt motor the speed of Induction motor operating in stable region A. decreases with increase in load B. increases with increase in load C. decreases with decrease in load D. none of the above is true

A. decreases with increase in load

The study of illumination involves A. design of lighting system B. study of lighting and wiring system C. calculation of wiring sizes for various lighting fixtures D. study of photometry and its application

A. design of lighting system

A smooth output from a generator is obtained by a A. design of the armature winding B. changing the form of the commutator C. changing the field strength D. leave as is

A. design of the armature winding

When 3 phase synchronous generator is supplying a zero pf lagging load the armature field affects the main field In the following way A. directly opposes it B. cross-magnetises it C. augments it directly D. none of these

A. directly opposes it

The speed of a dc motor is A. directly proportional to the back emf and inversely proportional to flux B. inversely proportional to back ernf and directly proportional to flux C. directly proportional to emt as well as flux D. inversely proportional to emf as well as flux

A. directly proportional to the back emf and inversely proportional to flux

In spite of the advantages of increasing voltage for distribution, the limiting factor are A. disproportionately greater cost of higher voltage cables and supplied to a consumer must be at consumer voltage B. voltage drop and the cost of higher voltage cable C. the power loss and cost of the higher voltage cable D. the power loss and voltage drop

A. disproportionately greater cost of higher voltage cables and supplied to a consumer must be at consumer voltage

For the same load, if the power factor of load is reduced, it will A. draw more current B. less current C. same current but less power D. less current but more power

A. draw more current

In electrical machines laminated core are used with a view to reduce A. eddy current loss B. copper loss C. hysteresis loss D. none of the above

A. eddy current loss

Maintenance factor and depreciation factor takes account of A. effect of dust, dirt and fall in light output of the lamp during its life B. depredation in capital cost of the installation C. effect of dust, dirt and the type of lamp used D. condition of the room and the type of lamp used

A. effect of dust, dirt and fall in light output of the lamp during its life

A region around a stationary electric charge has A. electric field B. magnetic field C. Both electric and magnetic field D. neither of the two

A. electric field

One of the advantages of a short pitch winding lies in A. elimination or suppression of harmonics B. reduction of voltages C. increasing the inductance D. reduction of circulating current

A. elimination or suppression of harmonics

Power in star connected system is A. equal to that of delta system B. 1.414 times the delta system C. 1.732 times the delta system D. 3 times the delta system

A. equal to that of delta system

In transformer the purpose of breather is to A. extract the moisture of the air B. to take insulating oil from the conservator C. to provide cooling to the winding D. to provide insulation to the winding

A. extract the moisture of the air

Transformer cores operating at microwave frequency ranges are generally made up of A. ferrites B. supermalloy C. silicon steel D. alnico V

A. ferrites

While comparing the magnetic and electric circuits, the point of dissimilarity exists while considering A. flux and current flow B. Permeance and conductance C. mmf and emf D. reluctance and resistance

A. flux and current flow

In an a.c. circuit, a low value of reactive volt ampere compared with watts Indicates A. high power factor B. unity power factor C. leading power factor D. zero power factor

A. high power factor

Cross over windings are used for A. high voltage winding of small rating transformers B. low voltage winding of small rating transformers C. high voltage winding of large rating transformers D. none of these

A. high voltage winding of small rating transformers

The special silicon steel is used for laminations because A. hysteresis losses are reduced B. eddy current losses are reduced C. both the above losses are reduced D. none of these

A. hysteresis losses are reduced

Distributing the armature winding of alternator is more than one number of slots per pole per phase results in A. reduction of irregularities produced in the waveform B. economy of materials used in winding C. less weight of the entire armature D. increase of generated emf per phase

A. reduction of irregularities produced in the waveform

If the number of poles in a lap wounded generator is increase by a factor of 2 the generated end will A. remain the same B. increase by a factor of 2 C. decrease by a factor of 2 D. increase by a factor of 4

A. remain the same

DC series motors are best suited for traction work because A. torque is proportional to the square of armature current and speed is inversely proportional to torque B. torque is proportional to the square of armature current and speed is proportional to torque C. torque and speed are proportional to square of armature current D. none of the above

A. torque is proportional to the square of armature current and speed is inversely proportional to torque

Separators in storage battery cells are designed to prevent the plate from A. touching the electrolyte B. touching the container C. shorting together D. shorting to the sediment

A. touching the electrolyte

When a steel toroidal ring is magnetized passing current through its coils, it develops no magnetic poles A. true B. false C. don't care D. don't know

A. true

For a uniformly distributed winding the value of distribution factor is A. unity B. 0.96 C. 0.866 D. 0.955

A. unity

The armature reaction of an alternator will be cross-magnetising of the power factor of the load A. unity B. less than unity C. more than unity D. zero leading

A. unity

Hysteresis losses can be reduced by A. using grain-oriented silicon steel B. increasing the frequency of the field C. laminating the core D. none of theses

A. using grain-oriented silicon steel

A distributor is designed from the point of view of A. voltage drop B. current carrying capacity C. both a and b D. load capacity

A. voltage drop

Torque under running condition at the slip 'S' A. which makes rotor reactance/phase equal to rotor resistance/phase B. which makes rotor reactance/phase greater than rotor resistance/phase C. which makes rotor resistance/phase lesser than rotor resistance/phase D. which is independent of rotor resistance

A. which makes rotor reactance/phase equal to rotor resistance/phase

In a dc motor iron losses occur in A. yoke B. the armature C. the field D. none of these

A. yoke

Ideal transformer assumptions do not include A. zero reactance of the windings B. zero resistance of the windings C. no leakage flux d no saturation core D. no saturation core

A. zero reactance of the windings

The r.m.s value of sine wave is equal to A. 0.637 max value B. 0.707 max. value C. 0.506 max. value D. 1.414 max. value

B. 0.707 max. value

A 3-phase, 4-pole. 24 slots alternator has its armature coils short-pitched by one slot Its pitch factor will be A. 1.0 B. 0.966 C. 0.96 D. 0.94

B. 0.966

In resonant circuit, the power factor at resonance is A. zero B. 1 C. 0.5 D. 0.707

B. 1

Three 10:1 single phase, step-down transformers are connected in Y/delta. For a primary line to line voltage of 3980 V, find the corresponding line voltage on the secondary side A. 398 V B. 230 V C. 3980 V D. 0 V

B. 230 V

If the current in the armature of dc series motor is reduced to 5% the torque of the motor will become A. 50% of the previous value B. 25% of the previous value C. 150% of the previous value D. 125% of the previous value

B. 25% of the previous value

For an unbalanced load, which connection is suitable A. 3-wire open delta B. 4-wire star connection C. 3-wire delta connection D. 3-wire star connection

B. 4-wire star connection

The value of permeability for the free space is A. 4 x 107 H/m B. 4pi x 10-7 H/m C. 4pi x 107 H/m D. 1/(4pi) x 107 H/m

B. 4pi x 10-7 H/m

The speed of a synchronous motor connected to 50 cycle supply is 1000 rpm the number of poles it must have A. 4 B. 6 C. 8 D. 10

B. 6

The voltage applied across an electric press was reduced by 50 %. The power consumed by the press will be reduced by A. 25 % B. 75 % C. 60 % D. 50 %

B. 75 %

Absolute permittivity of vacuum is taken as A. 8.854 x 10-6 f/m B. 8.854 x 10-12 f/m C. 8.854 x 10-9 f/m D. 1 f/m

B. 8.854 x 10-12 f/m

MNA makes an angle of ____ with the flux passing through the armature A. 0 B. 90 C. 45 D. 180

B. 90

The voltage v = 90 cos(wt-161.5) may be represented as sine function by A. 90 sin(wt+18.5) B. 90 sin (wt-71.5) C. 90 sin(wt+71.5) D. 90 sin(wt-18 5)

B. 90 sin (wt-71.5)

For all substances chemical equivalent divided by electro-chemical equivalent A. 9650 coulombs B. 9650 coulombs C. 965 coulombs D. 96 5 coulombs

B. 9650 coulombs

If Om is the forward lead angle in radians, Z is the total number of conductors and I is the current in each armature pole, the demagnetizing ampere-turns/pole are given as A. ATa = ZIOm/180 B. ATa = ZlOm/2pi C. ATa= ZI(1/p-2OM3pi) D. none of these

B. ATa = ZlOm/2pi

Inductance is measured in terms of capacitance and resistance to A. schering bridge B. Anderson bridge C. Maxwell-wein bridge D. Wein bridge

B. Anderson bridge

According to hysteresis law, hysteresis loss in a A. B^1.2 B. B^1.6 C. B^0.6 D. B^3.6

B. B^1.6

Gas Turbine works on A. Carnot cycle B. Brayton cycle C. Dual cycle D. Rankine cycle

B. Brayton cycle

Heavy water is A. H2O B. D2O C. W2O D. B2O

B. D2O

Which of the following is used for rolling mills? A. DC shunt motor B. DC cumulative compound motor C. DC series motor D. DC differential compound motor

B. DC cumulative compound motor

For all symbols having their usual meaning, the emf generated in the lap winding is given by A. E = OLNP/(60x2) B. E = OZNP/(60A) C. E = OZNA/2P D. E = OZNA/120P

B. E = OZNP/(60A)

The output voltage of a generator is given by the equation A. E = V - laRa B. E= V+ IaRa C. E = -L di/dt D. E=-N dO/dt

B. E= V+ IaRa

Condition for maximum power output lot a dc motor is A. Eb=V B. Eb= V/2 C. Eb = laRa D. Eb= 0.5IaRa

B. Eb= V/2

Average value of a sine wave is sqrt(2) times the maximum value A. True B. False C. because of the gravity D. pick me!

B. False

The rated speed of a given dc motor is 1050 rpm. To turn the machine at rpm. which of the following speed control scheme will be used A. Armature current resistant control B. Field resistant control C. Ward-Leonard control D. none of these

B. Field resistant control

For a three phase transformer, turns ratio K is given as A. K= sqrt(3) x line voltage ratio B. K= line voltage ratio C. K= sqrt(3) x phase voltage ratio D. K= phase voltage ratio

B. K= line voltage ratio

If the input of the prime mover of an alternator is kept constant but the excitation its increased then A. KVA will be leading B. KVA will be lagging C. KW will be changed D. the power factor of the load remains constant

B. KVA will be lagging

While conducing short-circuit test on a transformer the following side is short-circuited A. HV side B. LV side C. primary side D. no side

B. LV side

Which of the following is not a high pressure boiler A. Loeffer boiler B. Lancashire boiler C. Velox boiler D. La-Mount boiler

B. Lancashire boiler

The magnetic potential in magnetic circuit can be measured in terms of A. farads B. M.M.F C. coulombs D. none of these

B. M.M.F

Compressor used in gas turbine is A. Screw compressor B. Multistage axial flow compressor C. plunger type compressor D. reciprocating compressor

B. Multistage axial flow compressor

Coulombs law for the force between electric charges most closely resembles with A. Gauss theorem B. Newton's law of gravitation C. law of conservation of energy D. newton's law of motion

B. Newton's law of gravitation

Magnetic flux produced due to the stator winding with three phase current frequency f and which is of constant value, rotates at synchronous speed. If P is the number of poles of the motor then the synchronous speed is given by A. Ns = 120P/f B. Ns = 120f/P C. Ns = 120fP D. Ns = 60f/P

B. Ns = 120f/P

Internal combustion engine never works on A. Diesel Cycle B. Rankine cycle C. Otto cycle D. Dual combustion cycle

B. Rankine cycle

Critical resistance of a dc generator Rc A. Rc inversely proportional to the speed B. Rc proportional to the speed C. Rc proportional to the square of the speed D. Rc inversely proportional to the square of the speed

B. Rc proportional to the speed

The maximum torque under running condition in terms of rotor reactance is given by A. Tmax = (K O S E2)/(2 X2) B. Tmax = (K O E2)/(2 X2) C. Tmax = (K O S E2) / X2^2 D. Tmax = (K O E2)/ (2 X2^2)

B. Tmax = (K O E2)/(2 X2)

Which relay is used for feeder? A. MHO relay B. Translay relay C. Merz-price protection D. Buchholz relay

B. Translay relay

If E2 = rotor emf/ phase at stand still, R2 = rotor resistance/ phase X2 = rotor resistance/ phase at stand still Then starting torque of an induction motor is A. Ts = (K1 E2 R2)/(R2^2 + X2^2)^0.5 B. Ts = (K1 E2^2 R1)/(R2^2 + X2^2) C. Ts = (K2^2 E2 X2)/(R2^2 + X2^2)^0.5 D. Ts = (K1 E2^2 X2)/(R2^2 + X2^2)

B. Ts = (K1 E2^2 R1)/(R2^2 + X2^2)

A source V has an internal impedance Zin = R + jX when it is connected ZL = R-jX, the power transferred is A. V^2/4R^2 B. V^2/4R C. V^2/R D. V^2/2R

B. V^2/4R

A moving iron type instrument has A. a linear scale (uniform scale) B. a non-linear scale C. its deflection is directly proportional to the current D. its deflection is directly proportional to the voltage

B. a non-linear scale

In order to find Z in Thevenin's theorem A. all independent voltage and current sources are short circuited B. all independent voltage sources are short circuited and all independent current sources are open circuited C. all independent current sources are short circuited and independent voltage source are open circuited D. all independent voltage sources are open circuited and all independent current sources are open circuited

B. all independent voltage sources are short circuited and all independent current sources are open circuited

In any transformer the voltage per turn in primary and secondary remains A. always different B. always the same C. always in ratio of K D. sometimes same

B. always the same

The advantage of using static capacitor to improve the power factor is because they A. are not variable B. are almost loss free C. provide continuous change of power factor D. highly efficient

B. are almost loss free

In case of alternator, the stator frame serves A. to protect the whole machine B. as a turn path for the flux C. to hold the armature stampings D. to verticate the armature

B. as a turn path for the flux

The supply undertaking is allowed the actual voltage at the consumers terminal A. because ac supply alternates during each cycle B. because of the voltage drop across the distributor C. owing to large load at the consumer end D. owing to variation of power factor along the distributor.

B. because of the voltage drop across the distributor

For reciprocity theorem to be applicable to a network in which A. generators are present B. capacitor is present C. inductor is present D. generators are not present

B. capacitor is present

Each of the two alternators operating in parallel are adjusted for unity power factor Increasing the field current of one A. causes its power factor to become leading B. causes its power factor to become lagging C. changes its speed D. increases its load

B. causes its power factor to become lagging

The action of the dry cell is to change A. chemical action to mechanical energy B. chemical action to chemical energy C. electrical energy into mechanical energy D. electrical energy into magnetic energy

B. chemical action to chemical energy

Polarization in dry cell can be get rid of by A. coating the electrodes of the cell B. chemical means C. discharging the cell D disposing the cell

B. chemical means

How would you determine from visual observation of the armature winding, whether a generator is lap or wave wound A. connection to the field winding B. connection to the commutator C. connection to the brushes D. the direction of the end connection

B. connection to the commutator

The problems associated with ac transmission system are A. high voltage drop, insulation and instability for long lines B. continuous loss even at no load, insulation and instability for long lines C. continuous loss due to charging current, high voltage drop and instability for long lines D. continuous loss due to charging current, high voltage drop and insulation.

B. continuous loss even at no load, insulation and instability for long lines

The main function of a commutator in a dc motor is to A. prevent sparking B. convert ac to dc C. reduce friction D. convert dc to ac

B. convert ac to dc

Which of the following statement is not correct? A. voltage source is an active source B. current source is a passive source C. resistance is a passive element D. conductance is a passive element

B. current source is a passive source

The phase angle for a series RC circuit is defined as the angle between the _____ and the ____ phasors A. current, resistance voltage B. current, total voltage C. resistance voltage, capacitor voltage D. R, Xc

B. current, total voltage

To a highly inductive circuit, a small capacitance is added in series. The angle between voltage and current will A. increase B. decrease C. remain nearly the same D. become undetermined

B. decrease

Eddy current losses in transformer core are reduced by A. increasing the thickness of laminations B. decreasing the thickness of laminations C. taking the wire of higher gauge for winding the transformer D. decreasing the air gap in the magnetic circuit

B. decreasing the thickness of laminations

In a capacitor the electric charge is stored in A. metal plates B. dielectric C. dielectric as well as metal plates D. terminals of the element

B. dielectric

In a capacitor, the electric charge is stored in A. metal plates B. dielectric C. dielectric as well as metal plates D. neither dielectric nor metal plates

B. dielectric

Which power plant cannot have single unit of 100 MW? A. hydro-electric power plant B. diesel power plant C. steam power plant D. nuclear power plant

B. diesel power plant

The resistance phasor of a series RC circuit points to the right. The capacitive reactance phasor points _____ while the diagonal of the rectangle having there two phasors as sided represents their ______ A. up, impedance B. down, impedance C. left, current D. up, total voltage

B. down, impedance

Conductor P carries current into the paper. The force on the conductor acts A. upward B. downward C. to the left D. to the right

B. downward

If e1 = A sin wt and e2 = B sin (wt-theta) then A. e1 lags e2 by theta B. e2 lags e1 by theta C. e2 leads e1 by theta D. e1 leads e2 by theta

B. e2 lags e1 by theta

Which of the following is a correct statement about eddy currents? A. eddy currents improve the efficiency of a motor B. eddy currents heat up the metal parts C. eddy current do not influence the movement D. eddy current are used for arc welding

B. eddy currents heat up the metal parts

The root mean square (r.m.s) value of ac is the same as A. instantaneous value B. effective value C. average value D. maximum value

B. effective value

When using Circuit laws and rules we must use A. maximum value B. effective value C. average value D. peak to peak value

B. effective value

The presence of electric current is made known by A. flashing B. effects produced C. cracking D. electric shock

B. effects produced

Inside a hollow spherical conductor A. electric field is constant B. electric field is zero C. electric field changes with distance from the center of the sphere D. zero in all surface

B. electric field is zero

The current is a branch of a network in case of Thevenin's theorem is the same if it were connected to a generator of A. different rating B. emf E1 and internal impedance Z1 C. low rating D. e.m.f E1 with internal impedance zero

B. emf E1 and internal impedance Z1

The current flowing in L and C at parallel resonant are A. zero B. equal C. infinite D. different

B. equal

The advantages of star connection for the same phase voltage is that it gives A. step down current B. extra step up voltage C. extra step up current D. extra step up power

B. extra step up voltage

A series resonant is capacitive at f = 100Hz. The circuit will be inductive somewhere at A. f < 100 Hz B. f > 100 Hz C. f = 100 Hz by increasing the value of the resistance D. NOTA

B. f > 100 Hz

Kirchhoff's voltage law is not valid for a non-linear network A. true B. false C. sometimes true D. trulse

B. false

The flux linked with a coil of inductance L carrying current I is dI/dt (LI) A. true B. false C. don't care D. don't know

B. false

A low tension distribution system consist of A. transmission lines, transformer and circuit breaker B. feeders, distribution and service mains C. feeders, transformers and distributors D. transmission lines, distributors and circuit breakers.

B. feeders, distribution and service mains

Nuclear reactor generally employ A. fussion B. fission C. both fussion and fission D. none of the above

B. fission

A 60 hz frequency would cause an electric light to A. turn on and off 120 times per second B. flicker noticeable C. turn on and off 180 times per second D. turn on and off 60 times per second

B. flicker noticeable

By providing a variable resistance across the series field (diverter) in the dc motor, speeds above normal can be obtain because A. armature current decreases B. flux is reduced C. line current decreases D. none of these

B. flux is reduced

The induced emf in the transformer secondary will depend upon A. maximum flux in the core and frequency only B. frequency, flux and number of turns in the secondary C. frequency and supply only D. number of turns in the secondary only

B. frequency, flux and number of turns in the secondary

An ideal voltage source is that which A. has terminal voltage in proportion to current B. has zero internal resistance C. has terminal voltage proportion to the load D. has infinite internal resistance

B. has zero internal resistance

The potentiometer wire should have A. high specific resistance and high temperature coefficient B. high specific resistance and low temperature coefficient C. low specific resistance and high temperature coefficient D. low specific resistance and low temperature coefficient

B. high specific resistance and low temperature coefficient

In synchronous motor which loss does not vary with load? A. copper losses B. hysteresis losses C. windage losses D. none of the above

B. hysteresis losses

One of the advantages of distributing the winding in alternators A. reduce harmonics B. improve voltage waveform C. reduce the amount of copper D. decrease the value of the voltage

B. improve voltage waveform

If the supply frequency to the transformer is increased, the iron loss will A. decrease B. increase C. do not change D. exponentially decay

B. increase

If a medium of a parallel plate capacitor consists of mica and air, the capacitance is increased by A. increasing the air space B. increasing the area of the plates C. decreasing the thickness of mica D. increasing the thickness of mica

B. increasing the area of the plates

Sensitivity of a potentiometer can be increased by A. decreasing the length of the potentiometer wire B. increasing the length of the potentiometer wire C. decreasing the current of the potentiometer wire D. decreasing the resistance of the rheostat

B. increasing the length of the potentiometer wire

Eddy current loss can be minimized by A. decreasing the resistance of the magnetic medium B. increasing the resistance of the magnetic medium C. decreasing the permeability of the magnetic medium D. increasing the permeability of the magnetic medium

B. increasing the resistance of the magnetic medium

Sparking occurs when a load switched off because the circuit has high A. capacitance B. inductance C. resistance D. reactance

B. inductance

Megger is an instrument to measure A. very low resistance B. insulation resistance C. Q of the coil D. Inductance of the coil

B. insulation resistance

In a power transformer the winding which is nearer to the iron core of the transformer A. is a HV winding B. is LV winding C. may be HV or LV winding D. it is sandwitching of the two windings

B. is LV winding

The advantage of a dry cell is that A. it gives more emf than a wet cell B. it can be stored indefinitely C. its internal resistance is low compared to wet cell D. it needs no depolarizer

B. it can be stored indefinitely

The effect of the inductance of a coil on constant direct current is that A. it strengthens the current B. it does not affect the constant direct current C. it decreases the current D. it causes a higher voltage drop

B. it does not affect the constant direct current

The voltage across the capacitor ______ the current through it by _____ A. lags, 45 B. lags, 90 C. leads, 0 D. leads, 90

B. lags, 90

An over-exited synchronous motor take a A. lagging current B. leading current C. lagging and leading current D. none of these

B. leading current

The curve representing ohm's law is A. a parabola B. linear C. sine function D. a hyperbola

B. linear

In moving-coil instrument, the scale used is A. non-linear scale B. linear scale C. square law scale D. log scale

B. linear scale

The two main defects of the primary cell are A. polarization and sulphation B. local action and polarization C. buckling and polarization D. suphation and buckling

B. local action and polarization

A natural magnet is called A. steel B. lodestone C. magnetism D. soft iron

B. lodestone

The shunt field of a compound generator is connected across both the series field and the armature. This connection is known as A. short shunt B. long shunt C. differential compound D. cumulative compound

B. long shunt

Distribution transformers have good all-clay efficiency due to A. low copper loss B. low iron-loss C. low copper as well as iron loss D. none of these

B. low iron-loss

The slip rings employed in a three phase alternator in hydrostation are insulated for A. extra high tension voltage B. low voltage C. full armature voltage D. very high voltage

B. low voltage

Luminous intensity is defined as A. lumen pet square meter B. luminous flux per unit solid angle C. illumination per square meter D. candela per unit solid angle

B. luminous flux per unit solid angle

What is the effect produced by electric motors? A. magnetic effect only B. magnetic as well as heating effect C. heating effect only D. heating as well as chemical effect

B. magnetic as well as heating effect

What is the common in the two windings of a transformer A. electric current B. magnetic circuit C. winding wire gauge D. none of these

B. magnetic circuit

Electric power is transformed from one coil to the other coil in a transformer A. physically B. magnetically C. electrically D. electromagnetically

B. magnetically

The sum of the magnetic moments in unit volume of the solid is called A. field strength B. magnetization C. permeability D. susceptibility

B. magnetization

Electrochemical equivalent is A. ratio of atomic weight of an element to atomic weight of hydrogen B. mass of the element liberated per unit of quantity at hydrogen C. ratio of atomic weight of valency D. none of the above

B. mass of the element liberated per unit of quantity at hydrogen

For transmission line, the standing wave ratio is the ratio of A. maximum current to minimum voltage B. maximum voltage to minimum voltage C. maximum reactance to minimum reactance D. peak voltage to rms voltage

B. maximum voltage to minimum voltage

Which medium has the highest value of dielectric strength A. glass B. mica C. porcelain D. quartz

B. mica

It is advisable to avoid line starting of induction motor and uses starter because A. starting torque is very high B. motor takes 5 to 7 times its lull load current C. it will pick up very high speed and may go out of step D. it will run in reverse direction

B. motor takes 5 to 7 times its lull load current

What will happen if the supply terminals of dc shunt motor are interchanged? A. motor will stop B. motor will run at its normal speed in the same direction as it was running C. the direction of rotation will reverse D. motor will run at a speed lower than the normal speed in the same direction

B. motor will run at its normal speed in the same direction as it was running

For maximum power transfer according to maximum power transfer theorem source impedance A. must be very large as compared to the load impedance B. must be complex conjugate of load impedance C. must be equal to the load impedance D. must be very small as compared to the load impedance

B. must be complex conjugate of load impedance

Externally, magnetic line of force travel A. south to south B. north to south C. negative to positive D. in both directions

B. north to south

If in a transformer the secondary turns are doubled and at the same time the primary voltage is reduced by half, then secondary voltage will A. be halved B. not change C. be four times as high D. be reduced to a quarter

B. not change

Synchronous motors are A. self-starting B. not self-starting C. essentially self-starting D. none of these

B. not self-starting

High speed alternators have rotor construction A. similar to dc machines B. of non-salient pole C. of salient pole D. none of the above

B. of non-salient pole

One farad is A. coulomb-joule B. one coulomb per volt C. Joule per volt D. one volt per coulomb

B. one coulomb per volt

Current transformer secondary is connected to an ammeter of 5 A range to measure line current of 1000 A. The ammeter Is to be serviced. Can it be removed A. without interfering with supply B. only after switching off the main current path C. both a and b D. by touching the terminals and measuring the current density by means of electrocuting your body and after that, tell Sir Seva "I am more powerful than you are".

B. only after switching off the main current path

Synchronous impedance of an alternator is defined as the ratio of A. short circuit voltage to short circuit current B. open circuit voltage to short circuit current C. short circuit current to no load current D. open circuit voltage to short circuit current for same value of excitation

B. open circuit voltage to short circuit current

Ideally depreciated value of the plants plus the accumulation of the depreciation fund should be equal to A. sinking fund B. original invested capital C. salvage value D. obsolescence rate

B. original invested capital

Reciprocity theorem is valid for A. active network only B. passive network only C. active and passive network both D. none of the above

B. passive network only

In delta connected system, the line current is A. 1.414 times phase current B. phasor sum of two phase current C. equal to the phase currant D. 1.732 times the phase current

B. phasor sum of two phase current

It is not desirable to leave a lead storage battery in a discharged state for a long time mainly because A. electrolyte will attack the container B. plates will become sulfated C electrolyte will become weak D. acid will evaporate

B. plates will become sulfated

In any dc generator the emf generated in the armature is maximum when A. rate of change of flux linked is minimum B. rate of change of the flux is maximum C. flux linked with conductor is maximum D. flux linked with conductor is minimum

B. rate of change of the flux is maximum

A wattmeter is installed in a balanced 3- phase system. The wattmeter will measure A. total power B. real power C. active power D. reactive power

B. real power

In the case of delta connected circuit, when one resistor is open, power will be A. unaltered B. reduced to 1/3 C. reduced to 1/9 D. reduced to 1/6

B. reduced to 1/3

The method which can be used to improved commutation process is A. increasing the resistance of the brushes B. reducing the number of turns in the armature coil and hence the number of segments in the commutator C. to neutralize the reactance voltage by producing a reversing emf in the short circuit coil under commutation D. all of the above

B. reducing the number of turns in the armature coil and hence the number of segments in the commutator

In most generators the output voltage is induced by A. rotating magnetic field past stationary coils B. relative motion between the field and the armature coil C. converting electrical energy into mechanical energy D. through commutators

B. relative motion between the field and the armature coil

An automatic device that operates at present values is known as A. mercury switch B. relay C. fuse D. contactor

B. relay

The phase angle of a series RL circuit is the angle between the ______ phasor and the ______ phasor A. resistance, inductive reactance B. resistance, impedance C. inductive reactance, impedance D. none of these

B. resistance, impedance

Four resistance R1,R2,R3 and R4 are connected in series against 220 V supply. The resistance are such that R1>R2>R3>R4. The least power consumption will be in A. resistor R1 B. resistor R4 C. resistor R3 D. resistor R2

B. resistor R4

The transient voltage that appears across the contacts at the instant of arc extinction is called A. recovery voltage B. restriking voltage C. supply voltage D. peak voltage

B. restriking voltage

To use lumen method of design, you must first find A. room index and the lumens B. room index and then coefficient of utilization C. light distribution from a polar curve and then coefficient of utilization D. coefficient of utilization and then room index

B. room index and then coefficient of utilization

In an induction motor A. rotor runs at a speed equal to the speed of stator field B. rotor runs at a speed which is always lesser than the speed of the stator field C. rotor runs at a speed which is always higher than the speed of the stator field D. b and c both are correct

B. rotor runs at a speed which is always lesser than the speed of the stator field

An electric current can neither be _____ nor _____ A. fell, seen B. seen, touched C. seen, produced any effect D. produced and felt

B. seen, touched

Residual magnetism is necessary in a A. separately excited generator B. self excited generator C. both of these D. none of these

B. self excited generator

Which of the following dc motor has the least drop in speed between no load and nominal load? A. shunt motor with commutating poles B. series motor without commutating poles C. compound motor without commutating poles D. series motor with commutating poles

B. series motor without commutating poles

Best protection is provided by HRC fuse in case of A. open circuits B. short circuits C. overloads D. none of the above

B. short circuits

Pitch factor is defined as the ratio of the emf's of A. distributed winding to full pitch winding B. short pitch coil to full pitch coil C. full pitch winding to short pitch winding D. full pitch winding to concentrated winding

B. short pitch coil to full pitch coil

Which of the following generators are preferred for parallel operations A. series generators B. shunt generators C. compound generators D. alternators

B. shunt generators

The laminations are made from A. low carbon steel B. silicon sheet steel C. nickel alloy steel stampings D. chrome steel sheets

B. silicon sheet steel

A material best suited for manufacturing a fuse wire is A. aluminum B. silver C. lead D. copper

B. silver

RMS value and the mean value is the same In the case of A. square wave B. sine wave C. triangular wave D. hall wave rectified sine wave

B. sine wave

During the load shedding A. system voltage is reduced B. some loads are switched off C. system power factor is changed D. system frequency is reduced

B. some loads are switched off

The condition of a liquid electrolyte is measured in terms of its A. current value B. specific gravity C. acid content D. cottage output

B. specific gravity

Electrolyte of a storage battery is formed by adding A. water to hydraulic acid B. sulfuric acid to water C. hydrochloric acid to water D. water to sulfuric acid

B. sulfuric acid to water

During which season the load on the power plant supplying power to a city will be highest A. rainy season B. summer C. winter D. autumn

B. summer

The illumination of a surface at any point is proportional to the _______ of the angle between the normal at that point and the direction of the luminous flux A. Sine B. tangent C. cosine D. cotangent

B. tangent

If the approximate value of the current to be measured is not known, measurement start on A. the lowest range and then increase the range B. the highest range and then increase the range C. the middle range and then decrease the range D. the middle range and then increase the range

B. the highest range and then increase the range

If the air gap of an induction motor is increased A. the magnetizing current will decrease B. the magnetizing current will increase C. the power factor will decrease d. none of these

B. the magnetizing current will increase

The torque of a motor A. the force N-m acting on the rotor B. the product of the tangential force on the rotor and its radius C. the electrical power in KW D. the power given to the load being driven by the motor

B. the product of the tangential force on the rotor and its radius

The armature current drawn by any dc motor is proportional to A. the voltage applied to the motor B. the torque required C. the flux required in the motor D. the speed of the motor

B. the torque required

The function of protective relay in a circuit breaker is A. to earth any stray voltages B. to close the contacts when actuating quantity reaches a certain predetermined values C. to limit the arcing current during the operation of the circuit D. to provide additional safety in the operation of circuit breaker

B. to close the contacts when actuating quantity reaches a certain predetermined values

The most important feature of superposition theorem application is A. that the process is ease very much B. to find dc level in a network that has both sources C. that number of equations needed to be solved is reduced very much D. none of the above

B. to find dc level in a network that has both sources

A simple method of increasing the voltage of a DC generator is A. to decrease the air gap flux density B. to increase the speed of rotation C. to decrease the speed of rotation D. to increase the length of the armature

B. to increase the speed of rotation

An external resistance is added in series with the field of a dc motor. When the motor runs, the effect of resistance is A. to reduce the speed of the motor B. to increase the speed of the motor C. to reduce the armature current drawn by the motor D. to reduce the losses

B. to increase the speed of the motor

The armature of a dc motor is laminated A. to reduce the hysteresis losses B. to reduce the eddy current tosses C. to reduce the inductivity of armature D. to reduce the mass of the armature

B. to reduce the eddy current tosses

Short-pitch cols in the alternators are used A. to reduce the size of the alternator B. to reduce the harmonics from the generated emf of the alternator C. to reduce the copper loss in the alternator D. to reduce the capacity of the alternator

B. to reduce the harmonics from the generated emf of the alternator

When this electrolyte of a storage battery is low it is usually proper to A. add a special weak and solution B. top up with distilled water c. charge the battery for a short time before adding an electrolyte D. drain the battery completely and fill it with fresh electrolyte

B. top up with distilled water

The number of coils in the meter of megger is A. one B. two C. three D. four

B. two

A factory takes a load of 1000 KW and have a reactive power of 0 KVAR. Its power factor is A. 0.6 B. unity C. 0 8 D. 0.7

B. unity

The minimum armature current of the synchronous motor corresponds to operation at A. 0.8 power factor lagging B. unity power factor C. zero power factor D. 0.5 power factor leading

B. unity power factor

The efficiency of the thermal power plant improves with A. increased quality of coal burnt B. use of high steam pressure C. lower load in the plant D. larger quantity of water used

B. use of high steam pressure

The magnetic coupling between the primary and the secondary windings of a transformer may be increased by A. increasing the number of laminations of the material B. using the magnetic core of low reactance C. changing the turns ratio of the transformer D. no means, because it is constant

B. using the magnetic core of low reactance

Squirrel cage induction motor has A. zero starting torque B. very small starting torque C. very high starling torque D. extra starting torque and it starts up from rest

B. very small starting torque

Regulation of an alternator is defined as the rise in terminal ______ when full load is thrown off expressed as percentage of the terminal _____ for the same value of excitation and speed A. current B. voltage C. rating D. power factor

B. voltage

Transformer is used to change the values of A. frequency B. voltage C. power D. power factor

B. voltage

Power fader is defined as the ratio of A. volt ampere in watts B. watts to volt ampere C. Volt ampere reactive to watts D. watts to volt ampere reactive

B. watts to volt ampere

Alternators mostly work on rotating field type principle which is different from dc machines where the field is stationary. Therefore the alternators A. don't obey Faraday's law B. work on Faraday's law C. don't obey Lenz's law D. don't obey Ohm's law

B. work on Faraday's law

A conductor of length L has current I passing through it, when it is placed in parallel to a strong magnetic field. The force experienced by the conductor will be A. BLI B. zero C. B^2 LI D. BL^2 I

B. zero

If f1 and f2 are half power frequencies and to be resonance frequency, the selectivity of RLC series circuit is given by A. (f2 - f0)/(f1 - f0) B. (f2 - f1)/f0 C. (f2 - f1)/(f1 - f0) D. (f2 - f1)/ 2f0

C. (f2 - f1)/(f1 - f0)

A capacitor of 100 uf is connected in series with a resistance of 1000 ohms. The time constant of the circuit is A. 1 sec B. 0.01 sec C. 0.1 sec D. 0.001 sec

C. 0.1 sec

The magnitude of the power factor of an RC circuit with R=10 ohms, Xc =10 ohms, I 2 amp effective is A. 1 B. 0.5 C. 0.707 D. 0

C. 0.707

Relative permittivity of vacuum is A. zero B. 8.854 x 10-6 C. 1 D. infinite

C. 1

The equivalent star element of a delta circuit (R1 = R2 = R3) A. 3R1 B. R1 C. 1/3 R D. NOTA

C. 1/3 R

A change of 5% in the supply voltage of a 3-phase induction motor will produce to its torque a change of approximately A. 5% B. 25% C. 10% D. 15%

C. 10%

The period of the voltage 2 cos [(4500pi)t] + 7 sin [(7500pi)t] is A. 2.51 s B. 2.51 ns C. 2.51 ms D. 2.51 us

C. 2.51 ms

The work required for two charges of Q1 = 1C and Q2 = 2C having a distance of 1 m to bring Q2 to Q1 is A. 8*pi*eo N-m B. 8*pi/eo N-m C. 2/(4*pi*eo) N-m D. 4*pi*eo N-m

C. 2/(4*pi*eo) N-m

A power plant supplying energy to a city will usually experience peak demand A. from midnight to early morning B. 8 AM to 12 NN C. 2PM to 6 PM D. 6 PM to 12 PM

C. 2PM to 6 PM

For high voltage ac circuit breakers, the rated short circuit current is passed for A. 0.01 sec B. 0.1 sec C. 3 sec D. 30 sec

C. 3 sec

Three phase displacement between phasors in polyphase system is always A. 90 degrees B. 120 degrees C. 360 degrees divided by the number of phases D. 60 degrees

C. 360 degrees divided by the number of phases

Two electric press are connected in parallel. The resistance of the first is 100 ohms and that of the second is 300 ohms. The total current taken by both the presses is 4 A. The ratio of the current taken by first : second will be equal to A. 2:3 B. 1:3 C. 3:1 D. 1.2:3

C. 3:1

The value of Joule's mechanical equivalent of heat, J is equal to A. 4.2 cal/J B. 2.4 J/cal C. 4.2 J/cal D. 4.2 J

C. 4.2 J/cal

For 66 kV lines. the number of insulator disc used is A. 8 B. 12 C. 5 D. 3

C. 5

A 3 phase, 400V, 50 Hz, 4 pole synchronous motor has a load angle of 10 degrees electrical. The equivalent mechanical degree will be A. 10 deg B. 5/2 deg C. 5 deg D. 1 deg

C. 5 deg

The surge impedance of transmission lines is about A. 100 ohms B. 250 ohms C. 500 ohms D. 50 ohms

C. 500 ohms

The synchronous speed of a 50 cycle 10 pole motor is A. 500 rpm B. 150 rpm C. 600 rpm D. 1000 rpm

C. 600 rpm

The time constant is the time it takes the current in an inductive circuit to rise to A. 66% of its final steady state value B. 70% of its final steady state value C. 63% of its final steady state value D. 50% of its final steady state value

C. 63% of its final steady state value

In a parallel plate capacitor of capacitance Co the electric field is E. If a dielectric slab with dielectric constant equal to 7 is introduced to fill capacitor completely, capacitance will become A. Co B. Co/7 C. 7Co D. Co/3.5

C. 7Co

Short transmission lines have a length not exceeding A. 40 km B. 20 km C. 80 km D. 100 km

C. 80 km

The power dissipated in a series RC circuit with R = 10 ohms and Xc = 10 ohms carrying an effective current of 3 ampere is _____ watts A. 30 B. 30/2 C. 90 D.90/2

C. 90

Kirchhoff's law is applicable to A. AC circuits only B. passive network only C. AC as well as DC circuits D. DC circuits only

C. AC as well as DC circuits

The voltage transformer ratio is A. E1/E2 B. N1/N2 C. E2/E1 D. N2/N1

C. E2/E1

The principle of operation of the induction motor is based on A. Faraday's law B. rotating magnetic field C. Flemming's right hand rule D. Ohm's law

C. Flemming's right hand rule

Which of the following contact point metals has the highest melting point A. silver B. tungsten C. Gold D. copper

C. Gold

Which of the following generating station has the maximum running cost A. Thermal power station B. Nuclear power station C. Hydro power station D. None of these

C. Hydro power station

Flame proof switchgears are usually preferred A. on substation B. on transmission lines of low voltage C. In mines D. In high MVA capacity

C. In mines

The shunt current flowing in a short shunt compound wound motor is given by A. Ish = V/Rsh B. Ish = (V + IscRsc)/Rsh C. Ish = (V-IscRsc)/Rsh D. none of these

C. Ish = (V-IscRsc)/Rsh

At every instant the direction of the secondary current in a transformer must be such as to oppose any change in flux. This is in accordance with A. Faraday's laws B. Joule's laws C. Lenz's laws D. Coulomb's laws

C. Lenz's laws

Maximum number of equalizer rings needed an electrical machine is equal to A. N = # of conductors / # of poles B. N = # of conductors / 2 x # of poles C. N = 2 x # of conductors / # of poles D. none of these

C. N = 2 x # of conductors / # of poles

If an electrical network having one or more than one voltage source, is transformed into equivalent electrical network with a single voltage source (which is short circuit current of previous circuit) with parallel internal resistance of the network with all current source replaced by their internal resistance The above illustration is called A. Theversn's theorem B. reciprocity theorem C. Norton's theorem D. Superposition theorem

C. Norton's theorem

Out of the following, which one is not unconventional source of energy A. tidal power B. geothermal power C. Nuclear power D. Wind energy

C. Nuclear power

Torque in an induction motor under running condemn is given by A. T = (K1 E2^2 R2)/(R^2 + SX^2) B. T = (K1 E2^2 R2)/(R2^2 + SX2^2) C. T = (K1 S E2^2 R2)/(R2^2 + (SX^2)^2) D. T = (K1 S E2^2 R2)/(R2^2 + X2^2)

C. T = (K1 S E2^2 R2)/(R2^2 + (SX^2)^2)

Armature Torque of a dc motor is given by A. T = 0.159 OZIaP/A kg-m B. T = 0.162/[2IcP/A] N-m C. T = 0.159 EbIa/N N-m D. none of these

C. T = 0.159 EbIa/N N-m

In an induction motor the torque is related with the supply voltage as A. T is proportional to V^0.5 B. T is proportional to V C. T is proportional to V^2 D. T is inversely proportional to V^2

C. T is proportional to V^2

Synchronization of alternators means A. connecting alternators in series B. transferring load from one alternator to another C. connecting alternators in parallel D. adjusting the excitation of alternators

C. connecting alternators in parallel

When the power factor is unity, the armature flux of an alternator will be A. demagnetising B. square wave form C. cross magnetising D. none of these

C. cross magnetising

When the electric train is moving down a hill the dc motor acts as A. dc series motor B. dc shunt motor C. dc series generator D. dc shunt generator

C. dc series generator

The reliability of an instrument means A. the life of an instrument B. the extent which the characteristics remain linear C. degree to which repeatability continues to remain with specific limits D. all of these

C. degree to which repeatability continues to remain with specific limits

The function of a compensating winding is to neutralize the A. reactance voltage generated and consequence of commutation B. cross magnetize the effect of armature reaction C. demagnetizing effect of armature reaction D. all of these

C. demagnetizing effect of armature reaction

The degaussing is the process of A. removing gasses from materials B. removal of magnetic impurities C. demagnetizing metallic part D. cancelling the gauss

C. demagnetizing metallic part

Which of the following materials does not have permanent magnet dipole A. paramagnetic B. antiferromagnetic C. diamagnetic D. ferromagnetic

C. diamagnetic

In the left hand rule, thumb always represent A. voltage B. current C. direction of force on conductor D. magnetic field

C. direction of force on conductor

High voltage alternators are usually of the rotating field type. This means the generated voltage is connected A. through the slip rings to the load B. through the slip rings of the rotating field C. directly to the load D. directly to the rotor

C. directly to the load

Which statement influence the capacity of a capacitor A. area of the plates, thickness of the plates and the rate of charge B. area of the plates, the electric and the rate of charge C. distance between the plates, dielectric and thickness of the plates D. distance between the plates, area of the plates and dielectric

C. distance between the plates, dielectric and thickness of the plates

Distribution factor Kd is defined as the ratio of emf's of A. distributed winding to full pitch winding B. concentrated winding to distributed winding C. distributed winding to concentrated winding D. full pitch winding to distributed winding

C. distributed winding to concentrated winding

The ratio of the Sum of individual maximum demand to the Maximum demand of installation is known as A. demand factor B. plant use factor C. diversity factor D. plant capacity factor

C. diversity factor

Power factor of an inductive circuit can be improved by connecting to it in A. series B. parallel C. either series or parallel D. depends on the value of the capacitor

C. either series or parallel

Ohm's law can be applied with certain reservations to A. rectifying devices B. semiconductors C. electrolytes D. none of the above

C. electrolytes

The highest speed attained by a dc shunt motor is A. equal to infinity of rated flux B. higher than no load speed at rated flux C. equal to no load speed at rated flux D. lower than no load speed at rated flux

C. equal to no load speed at rated flux

The growth of the current is an inductive circuit as follows A. hyperbolic law B. ohm's law C. exponential law D. linear law

C. exponential law

If P= number of pair of poles, f = the frequency on the Hz, S = speed in rpm, the relationship between the three for synchronous alternators as given as A. f = PS/ 60 B. P = fS/ 120 C. f = PS/ 120 D. S = fP/ 120

C. f = PS/ 120

The relationship between frequency f, number of revolutions per second n and pair of pole p is given by A. f = n/p B. f = n/2p C. f = np D. f = 2np

C. f = np

The frequency of the rotor current in an induction motor is given by (If f is the supply frequency f is the rotor frequency and S is the slip) A. f = Sf' B. f' = Sf' C. f' = Sf D. S = ff'

C. f' = Sf

Magnetic lines of force are called A. hysteresis B. current C. flux D. magnetomotive force

C. flux

A pump induction motor is switched on to supply 30% lower than its rated voltage. The pump runs. What wilt eventually happen A. start after some time B. continue to run at lower speed without damage C. get heated and consequently got damaged. D. Nothing will happen

C. get heated and consequently got damaged.

In a series circuit with two bulb A and B, and a voltage source, wherein a wire has been connected across bulb A, bulb A will A. not glow B. be of the same intensity of B C. glow brightly D. be dim

C. glow brightly

Leakage factor is A. less than unity B. equal to unity C. greater than unity D. none of the above

C. greater than unity

A 3-wire dc system of distribution is preferred in 2-wire dc system because of A. results in a savings of copper and has less resistance B. results in a savings of copper and makes two alternative voltage available C. has less resistance and results in less voltage drop D. makes two alternative voltage available and results in less voltage drop

C. has less resistance and results in less voltage drop

Which of the following is non-linear element? A. diode B. transistor C. heater coil D. electric arc with unlike electrode

C. heater coil

The presence of the current is only made known by the effect it produced. These important effects are A. heating, electric shock and generation B. generation, chemical and electric shock C. heating, magnetic and electric shock D. heating, magnetic and chemical

C. heating, magnetic and electric shock

The steel for construction of transformer core is made so as to have A. low permeability and high hysteresis B. low permeability and low hysteresis C. high permeability and low hysteresis D. high permeability and high hysteresis loss

C. high permeability and low hysteresis

When (n) cells each of emf (E) volts, and internal resistance (r) ohms are connected in series, the current (i) through an external resistance R ohms is given by A. i= E/(R+r/n) B. i = E/( R + r) C. i= nE/(R + nr) D. i = E/(r + nR)

C. i= nE/(R + nr)

In a series of RL circuit phasor diagram, total voltage may be represented by the _____ phasor and the resistor voltage may be represented the ______ phasor A. current, voltage B. current resistance, current C. impedance, resistance D. impedance, inductance

C. impedance, resistance

Moving coil instrument are used A. in an a.c. circuit only B. both a.c. and d.c. C. in d.c. circuit only D. for measuring voltage only

C. in d.c. circuit only

Cells are connected in parallel to A. increase the internal resistance B. decrease the current capacity C. increase the current capacity D. increase the voltage output

C. increase the current capacity

When the speed of alternator increases, the frequency A. decreases B. remains same C. increases D. changes

C. increases

When the stator windings are connected in such a fashion that the number of poles are made half, the speed of the rotor of a synchronous motor A. decreases to half the original value B. remains sane as the original value C. increases to two times the original value D. tends to become zero

C. increases to two times the original value

Good smoothing factor of a coil depends on the A. terminal voltage B. property of the wire of the coil C. inductance of the coil D. cross-sectional area of the wire of the coil

C. inductance of the coil

A(n) _______ stores and returns energy to a circuit while a (n) _________ dissipates energy A. resister, impedance B. resistor, inductor C. inductor, resistor D. inductor, reactance

C. inductor, resistor

Sparking between contact can be reduced by A. inserting resistance in the line B. inserting a capacitor in series with the contacts C. inserting a capacitor in parallel with the contacts D. all of the above

C. inserting a capacitor in parallel with the contacts

The transformer oil used in transformers provide A. cooling and lubrication B. insulation and lubrication C. insulation and cooling D. insulation, cooling and lubrication

C. insulation and cooling

To reduce the voltage drop at a particular feeding point or load, the system preferred is A. ring main B. radial C. interconnected D. radial arrangement super-imposed

C. interconnected

'Kick fuse' has A. square law characteristics B. linear characteristics C. inverse characteristics D. exponential characteristics

C. inverse characteristics

The resistance of low voltage side of a transformer A. is equal to resistance of its high voltage side B. is more than resistance of its high voltage side C. is less than the resistance of its high voltage side D. b or c

C. is less than the resistance of its high voltage side

Which of the statement given below is true about autotransformer? A. it has two separate windings connected in series externally B. it can only step down the voltage C. it has only one winding D. is most suitable for power transformation

C. it has only one winding

Nickel-cadmium dry cell is becoming popular in power supplies to electronic calculators because A. it has a standard shape B. it is dry C. it is rechargeable D. it is easily manufactured

C. it is rechargeable

It is preferable to start a dc series motor with some mechanical load on it because A. it will not turn at no load B. it will act as a starter to the motor C. it may developed excessive speed and damage itself D. none of these

C. it may developed excessive speed and damage itself

What effect on current flow does reversing the direction of movement of conductor in the magnetic field of a generator have A. neutralize the current flows B. has no effect on current C. it reverse the direction of current flow D. all of the above

C. it reverse the direction of current flow

Coupling coefficient k in terms much used in radio work, can be attained from A. k = m*sqrt(L1*L2) B. k = m*sqrt(L1/L2) C. k = m/sqrt(L1*L2) D. k = m*L1*L2

C. k = m/sqrt(L1*L2)

A 60 ampere hours battery has 6 ampere discharge rates. It will provide a current of A. 10 amperes for 6 hours B. 6 amperes for 10 hours C. 12 amperes for 5 hours D. 20 amperes for 3 hours To keep the terminals of lead acid storage battery free from corrosion, it is advisable to A. clean the terminals frequently B. charge for battery at frequent intervals C. keep the electrolyte level low D. apply petroleum jelly

C. keep the electrolyte level low

Synchronous motor is capable of being operated at A. lagging power factor only B. leading power factor only C. lagging and leading power factor D. none of these

C. lagging and leading power factor

The composition of a secondary cell is A. zinc, copper and dilute sulfuric acid B. zinc, carbon and dilute sulfuric acid C. lead, lead peroxide and dilute sulfuric acid D. pinag-halong sip-on at plema

C. lead, lead peroxide and dilute sulfuric acid

The power factor of a.c. circuit containing both a resistor and a capacitor is A. more than unity B. leading by 90 degrees C. leading power factor D. lagging power factor

C. leading power factor

In a series RC circuit, the current ____ the total voltage by an angle ______ A. lags, of 45 B. lags, of 0 C. leads, between 0 to 90 D. leads, of 90

C. leads, between 0 to 90

The total voltage in a series RL circuit _____ the current by an angle ____ A. lags, of 90 B. lags, between 0 to 90 C. leads, between 0 to 90 D. leads, between 90 and 180

C. leads, between 0 to 90

Overall efficiency of gas turbine is A. equal to Carnot cycle efficiency B. equal to Rankine cycle efficiency C. less than diesel cycle efficiency D. more than otto cycle and diesel efficiency

C. less than diesel cycle efficiency

Impurities in an electrolyte can cause an internal short circuit condition called A. depolarization B. electrolysis C. local action D. polarization

C. local action

The voltage applied to the field of a rotating cylindrical rotor type alternators A. high dc voltage B. high ac voltage C. low dc voltage D. low ac voltage

C. low dc voltage

In DC generators, lap winding is used for A. low voltage, low current B. high voltage, high current C. low voltage, high current D. low voltage, high current

C. low voltage, high current

Energy radiated continuously in the form of lighting waves is called A. luminous intensity B. lumen C. luminous flux D. illumination

C. luminous flux

Which of the following is a vector quantity? A. magnetic potential B. flux density C. magnetic field intensity D. relative permeability

C. magnetic field intensity

For underground cable system, the comparison is made with the same A. rms voltage between the conductor B. rms voltage between the conductor and the earth C. maximum voltage between the conductors D. maximum voltage between the conductors and the earth

C. maximum voltage between the conductors

A cell which is used as voltage reference source for instrument calibration is A. solar cells B. battery cell C. mercury-cadmium cells D. nickel-cadmium cell

C. mercury-cadmium cells

The coefficient of coupling between two air core coils depend on A. self-inductance of the two coils B. mutual inductance between two coils C. mutual inductance and self inductance of the two coils D. none of the above

C. mutual inductance and self inductance of the two coils

The principle of working of a transformer is A. static induction B. dynamic induction C. mutual induction D. self induction

C. mutual induction

All day efficiency of a transformer nA A. nA = Electrical efficiency of transformer B. nA > Electrical efficiency of transformer C. nA < Electrical efficiency of a transformer D. none of the above is true

C. nA < Electrical efficiency of a transformer

Power transformers are designed to have maximum efficiency at A. no load B. half load C. near full load D. little more than full load

C. near full load

Iron becomes magnetized by induction when it is A. heated B. suspended east and west C. near in one of the magnet D. heated with some materials

C. near in one of the magnet

A passive network has A. no emf source B. no current source C. neither emf nor current source D. none of these

C. neither emf nor current source

A passive network has A. no source of emf B. no source of current C. neither source of current nor source of emf D. non-active elements

C. neither source of current nor source of emf

The unit of field intensity is A. coulomb B. coulomb / m^2 C. newtons / coulomb D. all of these

C. newtons / coulomb

For overhead transmission line, three phase three wire system is A. superior over 1-phase, two wire midpoint earthed system B. superior over 2-phase, 4 wire system C. not superior over the other two D. not used in practice

C. not superior over the other two

Capital cost per kwh is highest in case of A. steam power plant B. diesel power plant C. nuclear power plant D. hydroelectric power plant

C. nuclear power plant

When current flows in a conductor heat is produced because A. heat is proportional to the square of the current B. of electronic collision C. of interatomic collision D. of Joule's law

C. of interatomic collision

Which is the common method of cooling a power transformer? A. air cooling B. air-blast cooling C. oil cooling D. natural cooling

C. oil cooling

What is the minimum number of wattmeters required for measuring power of a three phase balance load A. two B. four C. one D. three

C. one

For circuit breaker "Break Time' is A. same as opening time B. opening time + arc duration C. opening time + arc duration + resistor current duration D. closing time, one last call for alcohol so finish your whiskey or beer

C. opening time + arc duration + resistor current duration

The over current protection for motor is provided by A. cartridge fuses B. kit kat fuses C. over current relay D. all of the above

C. over current relay

The simplest and most convenient form of detector used in a wheatstone bridge for audio frequency range is A. galvanometer B. vibration galvanometer C. pair of headphones D. cathode ray tube indicator

C. pair of headphones

Efficiency is a secondary consideration in case of A. base load plants B. both peak and base load plants C. peak load plants D. none of these

C. peak load plants

Two transformers when operating in parallel will share the load depending upon their A. magnetising current B. leakage reactance C. per unit impedance D. efficiency

C. per unit impedance

For economy in generation of power A. the load factor should be high B. the diversity factor should be high C. plant utilization factor should be high D. load factor and diversity factor should be low

C. plant utilization factor should be high

In huge alternators the moving part is A. brushes B. armature C. poles D. none of those

C. poles

The armature of a DC generator is laminated to A. reduce the bulk B. insulate the core C. reduce the eddy current loss D. provide passage for cooling air

C. reduce the eddy current loss

The effect of the dielectric is to A. increase the capacitance B. decrease the capacitance C. reduce the working voltage D. increase the distance between the plates

C. reduce the working voltage

As the load is increased, the speed of shunt motor A. remains constant B. increase slightly C. reduces slightly D. none of these

C. reduces slightly

Interpoles are meant for A. increasing the speed of the motor B. decreasing the counter emf C. reducing sparking at the commutator D. converting armature current to dc

C. reducing sparking at the commutator

Poor power factor results in all of the following except A. overloading of transformers B. overloading of alternators C. reduction in power losses D. reduction in load handling capacity of electrical system

C. reduction in power losses

The magnetism that remains in a magnet after magnetizing force has been removed is A. permeability B. induction C. residual D. saturation

C. residual

The two types of distribution system used are A. radial and delta B. radial and star C. ring main and radial D. ring main and delta

C. ring main and radial

Two of the power supply terminals to a 3-phase induction motor got interchanged during reconnection after maintenance of the motor, when put back into service, the motor will A. fail to rotate B. rotate in the same direction as it was prior to maintenance C. rotate in the reverse direction to that prior to maintenance D. unsa may panan aw nimu? Hunahunaa daw! Ayaw pagsalig sa choices! Di ka EE kung di ka kahebaw ani

C. rotate in the reverse direction to that prior to maintenance

A 230V de series motor is connected to 230Vac. It will A. run slowly B. not run at all C. run with less efficiency D. none of these

C. run with less efficiency

One dc motor drives another dc motor. The second dc motor when excited driven A. runs B. does not run as a generator C. runs as a generator D. also run as a motor

C. runs as a generator

The magnitude of mutual flux in a transformer is A. low at low loads and high at high loads B. high at low loads and low at high loads C. same at all levels D. varies at low loads and constant at high loads

C. same at all levels

To synchronize alternator, three conditions must be fulfilled, namely A. same voltage ratio, same frequency and voltages should be in phase with respect to external circuit B. same voltage, same frequency and voltage should be in phase opposition with respect to the external circuit C. same voltage, same frequency and voltages should be in phase opposition with respect to local series circuit D. same voltage ratio, different frequencies and proper phase relation of the voltages

C. same voltage, same frequency and voltages should be in phase opposition with respect to local series circuit

In a shunt generator the voltage built up generally restricted by A. speed limitation B. armature heating C. saturation of iron

C. saturation of iron

Ohm's law does not apply to A. conductors B. conductors when there is change in temperature C. semi-conductor D. ac circuit

C. semi-conductor

Which of the following motors is suitable for high starting torque? A. shunt motor B. cumulative compound motor C. series motor D. compound motor

C. series motor

The relative permeability of material means A. slightly less than 1 B. equal to 1 C. slightly greater than 1 D. very much greater than 1

C. slightly greater than 1

The rotor speed of an induction motor is A. the same as the synchronous speed B. faster than the synchronous speed C. slower than he synchronous speed D. determined by frequency and number of poles

C. slower than he synchronous speed

The superposition theorem requires as many circuits to be solved as there are A. meshes B. nodes C. sources D. all of the above

C. sources

In dc shunt motor, if the terminal voltage is reduced to half and torque remains the same then A. speed will be half and armature current remains the same B. speed will be half but armature current remain the same C. speed will be half and armature current becomes double D. speed and armature current will remain the same

C. speed will be half and armature current becomes double

The maximum current that can be supplied by alternators depends upon the A. strength of the exciter B. number of poles C. strength of the magnetic held D. maximum heat dissipation

C. strength of the magnetic held

Which of the following has the highest value of relative permeability A. iron B. mu-metal C. supermalloy D. 4% Si-Fe

C. supermalloy

For ac distributors, the power factor of the load has to be taken into consideration and the calculations became cumbersome. The approximate method which gives results within ± 5% of the actual voltage drop involves calculating A. the center of gravity of the load and the average power factor B. the center of gravity of the load, the point of minimum potential and average Power C. the center of gravity of the load, resistance and reactance per double run and average power factor D. the average power factor, the point of minimum potential and resistance and reactance per double run

C. the center of gravity of the load, resistance and reactance per double run and average power factor

Caray- Foster bridge is specially designed to determine A. the high resistance of the wire B. the internal resistance of the battery C. the difference between two nearly equal resistances D. the emf of the voltage source

C. the difference between two nearly equal resistances

The synchronous motor is not inherently sell starting because A. the rotating magnetic field does not have enough poles B. the rotating magnetic field is produced by only 50 Hz frequency currents C. the force required to accelerate the rotor is to the synchronous speed in an instant is absent D. the starling devices to accelerate the rotor to near synchronous speed Is absent

C. the force required to accelerate the rotor is to the synchronous speed in an instant is absent

Sensitivity in accuracy of a recording instrument means A. the amount of input required to produce unit pen detection B. the smallest signal required to produced detectable output C. the maximum error in sensitivity displayed by a pen D. degree to which the instrument is not sensitive enough to repeat readings

C. the maximum error in sensitivity displayed by a pen

The specific resistance is depends upon A. the area of cross-section and the length of the conductor B. the material of the conductor, its area of cross-section and length C. the nature of the material D. the area of cross-section of the conductor

C. the nature of the material

In an ideal transformer on no-load, the primary applied voltage is balance by A. the secondary voltage B. the drop across resistance and reactances C. the secondary induced emf D. the primary induced emf

C. the secondary induced emf

Synchronous motor always runs at A. a speed less than synchronous speed B. a speed more than synchronous speed C. the synchronous speed D. none of these

C. the synchronous speed

The condition in the Ohm's law is that A. ratio V/I should be constant B. current should be proportional to voltage C. the temperature should remain constants D. temperature should vary

C. the temperature should remain constants

What is the function of the zero - adjust control in a multi-meter A. it serves to conduct the current B. with this control. the sensitivity of a meter can be changed C. the zero point is corrected with the help of this control D. the moving parts can be tightened to the casing with the help of this control screw

C. the zero point is corrected with the help of this control

A relay used for protection of motors against overload is a A. impedance relay B. electromagnetic attraction type C. thermal relay D. Buchholz's relay

C. thermal relay

Which of the following has a negative coefficient of resistance A. wire wound resistor B. non-metals C. thermistor D. metals

C. thermistor

The type of a.c. distribution system commonly used to supply both light and power is the A. open delta system B. three phase delta system C. three phase star system with neutral wire D. three phase star system without neutral line

C. three phase star system with neutral wire

Which of the following methods of generating electric power from the sea water is more advantageous A. water power B. ocean power C. tidal power D. none of these

C. tidal power

For two alternators operating in parallel, If the load shared by one of them is to be increased, its field excitation is A. to be strengthened keeping input torque same B. to be weakened keeping input torque same C. to be kept constant but input torque should be increased D. None of these

C. to be kept constant but input torque should be increased

The main reason for using springs in a measuring instrument is A. to conduct current in the coil B. to hold the pivot in position C. to control the pointer movement D. to minimize the vibration of the power

C. to control the pointer movement

In a slip ring induction motor, resistance is connected in rotor phases A. to limit the starting current B. to increase starting current C. to limit stating current and increase starting torque D. none of these

C. to limit stating current and increase starting torque

The power is to be measured for a balanced delta connected load whose terminals cannot be opened. How many wattmeters do you need A. Four B. one C. two d. three

C. two

One factor affecting the voltages of the primary cell is the A. area of the plates B. distance between the plates C. type of plates and electrolytes D. thickness of the plates

C. type of plates and electrolytes

The power factor of an incandescent bulb is A. 0.8 lagging B. 0.8 leading C. unity D. zero

C. unity

Which of the following Is not the method of arc dispersion A. oil immersion of contacts B. magnetic blow out of arc C. use of rectifier D. de-ionization of arc path

C. use of rectifier

A low utilization factor for a plant Indicates that plant is A. used for base load only B. under maintenance C. used for stand by purpose only D. used for peak load as well as base load

C. used for stand by purpose only

What are the minimum requirements to cause the flow of current? A. voltage source, an ammeter, a conductor and insulator B. voltage source, a switch and a resistor C. voltage source and a conductor D. voltage source, a conductor and an insulator

C. voltage source and a conductor

Resistors commonly used in power circuits are A. carbon resistor B. etched circuit resistor C. wire wound resistor D. deposited metal resistor

C. wire wound resistor

The imaginary or fictitious part of synchronous reactance takes care of A. copper losses B. voltage regulation C. armature reaction D. inductive reactance

C. armature reaction

In compensation theorem a network containing generator can be replaced by A. its zero internal impedance B. its infinite impedance C. another generator D. LC circuit

D. LC circuit

Breaking capacity of a circuit breaker is usually expressed in terms of A. Amperes B. Volts C. MW D. MVA

D. MVA

To obtain a high voltage of about 1.9 V from a dry cell one would use A. Western standard cell B. Leclanche cell C. Nickel-Cadmium cell D. Magnesium cell

D. Magnesium cell

Which of the following is a conducting medium for electric current A. low temperature gas B. high temperature gas C. Dissociated gas D. Plasma

D. Plasma

The best and the most accurate method for determining the voltage regulation is A. synchronous Impedance method B. MMF method C. EMF method D. Potier triangle method

D. Potier triangle method

For distortionless transmission line (G = shunt conductance between two wires) A. RL = GC B. RG = LC C. RLGC = 0 D. R/L = G/C

D. R/L = G/C

The net reactance in an RLC circuit is A. XL B. Xc C. Xc + XL D. XL - Xc

D. XL - Xc

The cell used in a potentiometer is A. a dry cell B. a Daniel cell C. a Lachlanche cell D. a Lead accumulator

D. a Lead accumulator

The function of the interpole of compole is A. to neutralize the reactance of the voltage and help in commutation process B. to neutralize the cross-magnetizing effect of the armature reaction C. to neutralize the demagnetizing effect of the armature D. a and b

D. a and b

There are no self-induced voltage in the coil when A. an ac current flows through the coil B. current decreases from 0.1 to 0 A in 1 second C. current increases from 0 to 0.1 A in 1 second D. a dc current flows through the coil

D. a dc current flows through the coil

What is the efficiency of transformer compared with that of electrical motors of the same power? A. much smaller B. somewhat smaller C. much higher D. about the same

D. about the same

If theta is the angle measured in electrical degrees between any point on the pole face and center of the pole then for setting a sinusoidal wave as the output, the air gap at that point should be such that A. air gap is proportional to sin theta B. air gap is proportional to cos theta C. air gap is inversely proportional to sin theta D. air gap is inversely proportional to cos theta

D. air gap is inversely proportional to cos theta

Dielectric strength of a material depends on A. moisture content B. thickness C. temperature D. all of the above

D. all of the above

Generators are often preferred to be run in parallel because of having of the advantages of A. great reliability B. generator efficiency C. meeting greater load demands D. all of the above

D. all of the above

In a circuit breaker, the active recovery voltage depends upon A. power factor B. armature reaction C. circuit condition D. all of the above

D. all of the above

In power plant, insurance cover provided for A. equipment only B. skilled worker only C. unskilled worker only D. all of the above

D. all of the above

Interrupting medium in a contactor may be A. air B. SF6 gas C. oil D. all of the above

D. all of the above

Short circuit test on the Induction motor can be used to find out A. the transformation ratio of the induction motor B. power scale of circle diagram C. copper losses in the induction motor D. all of the above

D. all of the above

The current carrying capacity of the fuse material depends on A. length B. material C. cross-sectional area D. all of the above

D. all of the above

The disadvantage offered by unwound system is A. frequent arcing grounds B. difficult earth fault relaying C. voltage oscillation D. all of the above

D. all of the above

The induction motors are designed for A. three phase B. two phase C. single phase D. all of the above

D. all of the above

The surge impedance of overhead lines is taken as A. 50-60 ohms B. 1000-2000 ohms C. 10-20 ohms D. 100-200 ohms The effect of corona is A. increased reactance B. increased inductance C. increased energy loss D. all of the above

D. all of the above

Which of the following are air break switching devices A. isolator B. limit switch C. earthing switch D. all of the above

D. all of the above

A VTM is more reliable as compared to multi-meter for measuring voltage across low impedance because A. its sensitivity Is very high B. it offers high input impedance C. It does not alter the measured voltage D. all of these

D. all of these

A low voltage is measured on a higher scale of a voltmeter. The measurement would have A. low accuracy B. low precision C. low resolution D. all of these

D. all of these

The disadvantage associated with an electrodynamic instrument is that A. it consumes more power B. it has low torque to weight ratio C. its frequency range is low D. all of these

D. all of these

The magnetization in any material appears as a result of A. electron orbitals motion B. electron spin C. spin of the nucleus about the axis D. all of these

D. all of these

Switching surges may be caused by A. closing of uncharged line B. load shedding of receiving end of the line C. switching of magnetizing current D. any of the above

D. any of the above

The over voltage surges in power system may be caused by A. lightning B. switching C. resonance D. any of the above

D. any of the above

The protection against over-voltage due to lightning is provided by A. use of surge diverter B. low tower footing resistance C. use of overhead ground wires D. any of the above

D. any of the above

A partially discharged lead storage battery may be brought back to full charged by A. adding sulfuric acid B. adding distilled water C. applying ac voltage across the terminals D. applying dc voltage across the terminals

D. applying dc voltage across the terminals

A transformer operates A. always at unity power factor B. has its own power factor C. at power factor below a particular value D. at power factor depending on the power factor of the load

D. at power factor depending on the power factor of the load

The consumer main switchgear is usually located A. at the center of the house B. out of reach C. over the kitchen sink D. at the intake position

D. at the intake position

The driving power from the prime mover driving an alienator is lost but the alternator remains connected to the supply network and field supply is on. The alternator will A. gel burnt B. behaves as an induction motor C. behaves as synchronous motor but will rotate in reverse direction to that corresponding to generator action D. behave as a synchronous motor and will rotate in the same direction

D. behave as a synchronous motor and will rotate in the same direction

External characteristics of DC generators can be obtained by A. internal characteristics B. no load saturation characteristics C. armature resistance drop D. both a and b

D. both a and b

The method most commonly used for synchronizing the alternators in a power house is A. dark lamp method and a synchroscope B. dark lamp method only C. bright lamp method D. bright lamp method and a synchroscope

D. bright lamp method and a synchroscope

How can the inductance of the coil can be increased? A. by increasing the current B. by thick layers of hard paper in the gap C. by connecting ohmic resistance in series D. by increasing the number of turns

D. by increasing the number of turns

The luminous intensity of a lamp is expressed in A. Watts B. lumens C. Lux D. candela

D. candela

Adjustment of field excitation on one of the two alternators operating in parallel will A. increased its load B. change its frequency C. decrease its load D. change its power factor

D. change its power factor

The transient current are due to A. voltage applied to circuit B. resistance of the circuit C. impedance of the circuit D. changes in the stored energy in the inductance and capacitance

D. changes in the stored energy in the inductance and capacitance

Which of the following component of a dc generator plays vital role for providing a direct current of a DC generator A. dummy coils B. equalizer ring C. eye bolt D. commutator

D. commutator

For which of the following dc motors is the typical field of application mentioned? A. shunt motor: electric trains B. series motor: machine tools C. series motor: belt drive D. compound motor: wheel drive

D. compound motor: wheel drive

No voltage will be induced in a coil when current is A. switched on B. switched off C. reduced D. constant

D. constant

Air gap in the iron core of an inductor prevents A. hysteresis loss B. flux change C. transformer action D. core saturation

D. core saturation

The phase angle of series RL circuit may be computed ______ as _____ or ____ or ____ A. cos-1 (R/XL), sin-1 (XL/R), tan-1(R/Z) B. cos-1 (R/Z), sin-1 (XL/R), tan-1 (R/XL) C. cos-1 (Z/XL), sin-1 (R/Z), tan- 1 (XL/R) D. cos-1 (R/Z), sin-1 (XL/Z), tan-1 (XL/R)

D. cos-1 (R/Z), sin-1 (XL/Z), tan-1 (XL/R)

The motor used for intermittent, high torque is A. dc shunt motor B. dc series motor C. differential compound motor D. cumulative compound motor

D. cumulative compound motor

Each ferromagnetic material has characteristic temperature above which its properties are quite different from those below that temperature. These temperature is called A. transition temperature B. faraday's temperature C. demagnetization temperature D. curie temperature

D. curie temperature

The left hand rule correlates A. self-induction, mutual induction and direction of force on a conductor B. magnetic field, electric field and direction of force on a conductor C. current induced emf and direction of force on a conductor D. current, magnetic field and direction of force on a conductor

D. current, magnetic field and direction of force on a conductor

In series as well as parallel resonant circuits, increasing the value of resistance would lead to A. Increase in the band-width of both the circuits B. decrease in the band-width of both the circuits C. increase in band width in series circuit and decrease in parallel circuit D. decrease in band-width in series circuit and increase in parallel circuit

D. decrease in band-width in series circuit and increase in parallel circuit

A variable resistance is connected across a constant voltage E volts. The value of resistance is gradually increased. The graph which shows relationship between current I and resistance R is A. positively linear B. negatively linear C. horizontally straight D. exponentially decrease

D. exponentially decrease

The basic function of a circuit breaker is to A. produce the arc B. ionize the surrounding air C. transmit voltage by arcing D. extinguish the arc

D. extinguish the arc

The useful life of a diesel engine in a plant is expected to be A. five years B. one year C. fifty years D. fifteen years

D. fifteen years

From what source does a rotating field type alternator receive its exciter voltage A. from an externally controlled ac voltage B. from an externally controlled dc voltage C. from a self-excited source like shunt generator D. from an auxiliary generator driven by main generator shaft

D. from an auxiliary generator driven by main generator shaft

Stages in the provision of electrical energy to a consumer are: A. generation and transmission B. generation, distribution and transmission C. generation, dissipation and distribution D. generation, transmission and distribution

D. generation, transmission and distribution

SF6 gas A. is lighter than hydrogen B. is lighter than air C. has density 2 times as compared to that of air D. has density 5 times as compared to that of air

D. has density 5 times as compared to that of air

Electrolytic capacitor is the most commonly used type but it has two disadvantages A. low insulation resistance and suitable for DC only B. high insulation resistance and suitable for AC only C. high capacitance and high insulation resistance D. high capacitance and low insulation resistance

D. high capacitance and low insulation resistance

A coil with a large distributed capacitance has a A. low resistance B. low Q C. low resonant frequency D. high resonant frequency

D. high resonant frequency

In a series connection of bulb A and B in series also with a source, bulb B glows brighter because its resistance is A. in parallel with A B. in series with A C. lower than A D. higher than A

D. higher than A

For a parallel circuit consisting of resistance and reactance the value of power factor is the ratio of a A. impedance to reactance B. reactance to impedance C. resistance to impedance D. impedance to resistance

D. impedance to resistance

The force between two magnetic poles varies with distance between them. The variation is A. in direct proportion to the distance B. in inverse proportion to the distance C. in direct proportion to the square of the distance D. in inverse proportion to the square of the distance

D. in inverse proportion to the square of the distance

During summer months the load increases is due to A. increased water supply B. vacation in institutions C. increased business activities D. increased use of fans and air-conditioners

D. increased use of fans and air-conditioners

Improvement in the power factor in an induction motor A. decreases torque B. increases torque C. increases the current D. increases the torque and decreases the current due to increased impedance

D. increases the torque and decreases the current due to increased impedance

Which of the following statement about inductance of a coil is true? A. inductance is a characteristic of coils occurring only in case of ac B. inductance appears only if the coil has an iron core C. inductance is only another expression for self-induced voltage D. inductance characterizes the magnetic properties of a coil which are significant for the value of self-induced voltage generated due to current change in the coil

D. inductance characterizes the magnetic properties of a coil which are significant for the value of self-induced voltage generated due to current change in the coil

The speed of a series motor at no load is A. zero B. 3000 rpm C. 3600 rpm D. infinity

D. infinity

To reverse the direction of rotation of a three phase induction motor, it is necessary to A. interchange all three line connections B. reverse the polarity of the rotor circuit C. increase the resistance of the rotor circuit D. interchange any two of the three line connections

D. interchange any two of the three line connections

The illumination of a surface is A. directly proportional to its distance from the source B. inversely proportional to its distance from the source C. directly proportional to the square of its distance from the source D. inversely proportional to the square of Its distance from the source

D. inversely proportional to the square of Its distance from the source

In a parallel circuit the potential difference across the resistance A. varies B. is different from other voltage C. is sometimes constant D. is always constant

D. is always constant

A starter is necessary to start a dc motor because A. it starts the motor B. it limits the speed of the motor C. it limits the back emf to a safe value D. it limits the starting current to a safe value

D. it limits the starting current to a safe value

Which of the following statement, concerning the sinusoidal waveform, is most correct? A. it represents ac B. it represents dc C. it represents half-wave rectified ac D. it represents sum of ac and dc

D. it represents sum of ac and dc

The mass of an ion liberated at an electrode is directly proportional to the quantity of electricity which passes through the electrolyte. The above statement is associated to A. Gauss's theorem B. Laplace law C. Weber and Ewing theory D. laws of electrolysis

D. laws of electrolysis

Kaplan Turbine is A. a high head mixed flow turbine B. an impulse turbine, inward flow type C. a reaction turbine, outward flow type D. low head axial flow turbine

D. low head axial flow turbine

The rotor of an induction motor gets its power from A. the line voltage B. slip rings C. a centrifugal switch D. magnetic induction

D. magnetic induction

If the power factor is zero, the active recovery voltage will be A. minimum B. 0.5 C. 0.707 D. maximum

D. maximum

Comparison of various overhead transmission system is made with the same A. rms voltage between the conductor B. rms voltage between the conductor and the earth C. maximum voltage between the conductors D. maximum voltage between the conductors and the earth

D. maximum voltage between the conductors and the earth

For the series RLC circuit at resonance the current amplitude is _____ for a fixed voltage amplitude and power factor is A. minimum, zero B. minimum, unity C. maximum, zero D. maximum, unity

D. maximum, unity

Outward radial flow turbines A. are impulse turbines B. are reaction turbines C. are partly impulse partly reaction turbines D. may be Impulse or reaction turbines

D. may be Impulse or reaction turbines

Which of the following statement is correct? A. the resistance does not play an important role in electrical engineering B. the resistance of the wire does not depend on its material C. the resistance of most of the materials is independent of the temperature D. the resistance of the conductor is hindrance by which the conductor opposes the flow of current

D. the resistance of the conductor is hindrance by which the conductor opposes the flow of current

In an ideal transformer on no load, the voltage, applied across the primary winding of the temperature is balanced by A. the emf induced in the primary winding B. the drop across the impedance of primary side C. the drop across the impedance of secondary side D. the secondary induced emf

D. the secondary induced emf

Threshold of sensitivity with respect to instrument is A. the maximum signal which can be measured B. the value of sensitivity of the highest scale C. the value of sensitivity of the lowest scale D. the smallest signal that results in a detectable output

D. the smallest signal that results in a detectable output

The function of a commutator in a dc machine is A. to change alternating current to direct current B. to improve commutation C. for easy speed control D. to change alternating voltage to direct voltage

D. to change alternating voltage to direct voltage

The Mutual inductance of two coil is maximum when the coils are A. inclined at angle of 45 B. at the right angle to each other C. facing each other D. touching each other

D. touching each other

For ac transmission, whether overhead or underground system, the most unsuitable system is the A. three phase, three wire B. three phase, four wire C. single phase D. two phase

D. two phase

Which of the following is not a type of the contactor for circuit breaker A. electro-magnetic B. electro-pneumatic C. pneumatic D. vacuum

D. vacuum

Heating effect of current has undesirable side effect A. electric oven B. electric iron C. immersion heater D. vacuum cleaner

D. vacuum cleaner

During the charging period of a lead-acid battery, the charging rale is lowered to prevent violent gassing because A. the gasses given off are explosive B. evaporation of the electrolyte will weaken its effect C. the cells will be subjected to excessive pressure D. violent gassing tends to wash the active material from the plate

D. violent gassing tends to wash the active material from the plate

Shunt generators are used where the main requirement is a constant A. current and voltage B. current C. voltage over a wide load range D. voltage over a narrow load range

D. voltage over a narrow load range

The impedance triangle is similar to the ________ triangle with the resistance phasor in place of the _____ A. current, resistor current B. current, resistor voltage C. voltage, impedance D. voltage, resistor voltage

D. voltage, resistor voltage

A multi-meter consist of A. voltmeter and ohmmeter B. voltmeter and ammeter C. ammeter and ohmmeter D. voltmeter, ammeter and ohmmeter

D. voltmeter, ammeter and ohmmeter

A circuit breaker will normally operate A. when the switch is put-on B. when the line is to be checked C. when the power is to be supplied D. whenever fault in the line occurs

D. whenever fault in the line occurs

Which of the following statements is incorrect? If a starter is not used with large dc motor, it will draw a starting current which A. is many times its full-load current B. will produce excessive line voltage drop C. will damage the commutator D. will produce very low starting torque

D. will produce very low starting torque

The basic property of the transformer is that it changes he voltage level of an ac signal A. without changing the power B. without changing the shape C. without changing its frequency D. without changing power, frequency and shape

D. without changing power, frequency and shape

If the current and voltage are out of phase by 90 degrees, the power is A. 1.1 VI B. maximum C. minimum D. zero

D. zero

Power factor of the magnetizing component of a transformer is A. unity B 0.8 lagging C. always leading D. zero

D. zero

The flux for the whole cylinder is A. 2*pi*E*r*l - 2*E*pi*r^2 B. 2*pi*E*r*l + 2*E*pi*r^2 C. E*pi*r*l D. zero

D. zero

The ohmmeter reading for a shorted capacitor is A. infinity B. few kilo ohms C. few mega ohms D. zero

D. zero

The speed regulation of a 3-phase synchronous motor is A. 5% B. 1% C. 0.4% D. zero

D. zero

While a charging accumulators, one should A. check the acid level with a lighted match B. short the cell to see if they are fully charged C. keep in well ventilated space D. connect and disconnect them with the supply The output voltage of a single loop generator is a A. steady dc B. steady ac C. pulsating ac d. pulsating dc

d. pulsating dc

The relative permeability of iron is A. 5000 B. 7000 C. 3000 D. 1000

A. 5000

Which of the following bridge is used to measure inductance and high Q inductor? A. Maxwell bridge B. Hay bridge C. Wein bridge D. Anderson bridge

B. Hay bridge

The current drawn by armature of a dc motor is A. V/Ra B. Eb/Ra C. (V-Eb)/Ra D. (Eb-V)/Ra

C. (V-Eb)/Ra

A 4-pole lap-wound armature has 400 conductors and a flux per pole of mWb. The ernf generated, when running at 600 rpm, will be A. 240 V B. 120V C. 60V D. 30V

B. 120V

The value of slip at maximum torque condition (under running condition) in terms of R2 and X2 is A. S =X2/R2 B. S = R2/X2 C. S= 2R2/X2 D. S = E2/2X2

B. S = R2/X2

Which of the following method is most economical for finding the no-load of a large dc shunt motor is A. Hopkinson's test B. Swinburne's test C. retardation test D. none of these

B. Swinburne's test

Which of the following plant is expected to have the longer expected life A. steam B. hydro-electric C. diesel D. all have equal life

B. hydro-electric

A relay used in long transmission line is A. reactance relay B. impedance relay C. mho's relay D. no relay is used

C. mho's relay

Ohm's law is applicable to A. electric arc B. rectifying devices C. gas discharge lamps D. none of the above

D. none of the above

Out of the following circuit breaker, which one has the lowest voltage range A. Air-break circuit breaker B. Tank type oil circuit breaker C. Air-blast circuit breaker D. SF6 circuit breaker

A. Air-break circuit breaker

The luminous flux emitted in unit solid angle by a uniform point source having a luminous intensity of 1 candela is called A. lumen B. illumination C. lux D. luminance

A. lumen

Cells are connected in series to A. decrease the voltage output B. increase the voltage output C. decrease the internal resistance D. increase the current capacity

B. increase the voltage output

The resistance of a conductor, when its temperature is increased A. remain constant B. increases C. varies D. decreases

B. increases

Leclanche cell is most suited for A. continuous work B. intermittent work C. where large current is required D. where large voltage is required

B. intermittent work

Synchronizing power of a synchronous machine is A. equal to synchronous reactance B. inversely proportional to the synchronous reactance C. directly proportional to the synchronous reactance D. none of these

B. inversely proportional to the synchronous reactance

In 2-wattmeter method, the reading in one of the wattmeter is zero when A. power factor is unity B. power factor is 0.5 C. load in one of the phases is zero D. a neutral wire is not provided

B. power factor is 0.5

In two wattmeter method, the reading of the wattmeter will be identical when A. load in one of the phases is zero B. power factor is unity C. power factor is 0.5 D. neutral is earthed

B. power factor is unity

Carbon brushes are used in electric motors to A. brush off carbon deposits on the commutator B. provide a path for the flow of current C. prevent overheating on the armature windings D. prevent sparking during commutation

B. provide a path for the flow of current

When the sole purpose of an alternating current is to produced heat, the solution of conductor is based on A. average value of current B. peak value of current C. maximum value of current D. any of the above

C. maximum value of current

A capacitor having a capacitance of 30 uf is connected across 200 Vdc source. The charging current will be least A. when the capacitor is half-charged B. initially C. when capacitor is fully charged D. when capacitor is almost 75% charged

C. when capacitor is fully charged

In a given ac circuit when power factor is unity the reactive power is A. maximum B. equal to I^2 R C. zero D. infinite

C. zero

Open circuit voltage is the p.d. between two points when the impedance between these points is A. infinity B. reactive C. zero D. capacitive

C. zero

The power dissipated in a pure capacitor A. maximum B. minimum C. zero D. depends on the size of the voltage

C. zero

A current of 10 amperes at a power factor of 0 8 lagging is taken from 250 V ac supply. The reactive power of the system is A. 2000 watts B. 2000 VA C. 1500 watts D. 1500 VAR

D. 1500 VAR (obvious na kaayo sa unit uy, pwede ra dili e solve)

Which of the following theorems enables a number of voltage (or current) source to be combined directly into a single voltage (or current) source ? A. Compensation theorem B. Reciprocity theorem C. Superposition theorem D. Millman's theorem

D. Millman's theorem

Which if the following relations is incorrect? A. Capacity Factor = UF x LF B. Ave. Load = LF x MD C. MD = DE x CL D. None of the above

D. None of the above

In the Philippines, share of power is not provided by A. Diesel power plant B. Hydro-electric power plant C. Thermal power plant D. Nuclear Power plant

D. Nuclear Power plant

The material used for bus bars should have A. low resistivity B. higher softening temperature C. low cost D. all of the above

D. all of the above

The value of current at resonance in a series RLC circuit affected by the value of A. R B. C C. L D. all of these

D. all of these

A good transformer oil should be absolutely free from A. sulphur B. alkalies C. moisture D. all the above

D. all the above

Which of the following is a correct relation for an induction motor A. rotor efficiency = actual speed of rotor/ synchronous speed B. rotor on losses = slip x rotor input C. rotor input = 2pi x gross torque x Ns D. all the above relations are correct

D. all the above relations are correct

Which of the following material is used for making permanent magnets A. carbon steel B. platinum cobalt C. alnico V D. all three mentioned above

D. all three mentioned above

The speed of synchronous motor A. reduces as the bad increases B. increase as load increases C. adjusts itself to new equilibrium speed whenever load changes D. always remains constant

D. always remains constant

Current limiting reactors may be A. air cooled, air cored B. oil immersed magnetically shielded C. oil immersed non-magnetically shielded D. any of the above

D. any of the above

In DC generator, the cause of rapid brush wear may be A. imperfect contact B. severe sparking C. rough commutator surface D. any of the above

D. any of the above

Load shedding is possible through A. Switching off the loads B. frequency reduction C. voltage reduction D. any of the above

D. any of the above

Over voltage transient may occur due to A. lightning B. switching C. arcing ground D. any of the above

D. any of the above

Surge impedance of transmission line is given by A. square root of C/L B. square root of CL C. 1/ square root of CL D. square root of L/C

D. square root of L/C

In DC generator the ripples in the direct emf and generated are induced by A. using equalizer rings B. using commutator with large number of segments C. using carbon brushes with superior quality D. armature windings

B. using commutator with large number of segments

In a dc generator the flux is seen to be at the trailing pole tips and also at the leading pole tips A. weakened, weakened B. weakened, crowded C. crowded, weakened D. same, same

C. crowded, weakened

The induction motor differs from the synchronous motor is that it A. requires a dc source for its rotor B. does not require a rotating magnetic field C. current is induced in its rotor D. current is conducted in rotor

C. current is induced in its rotor

An electrodynamic meter can be used to measure A. ac voltage B. dc voltage C. dc as well as ac voltage D. dc voltage but for ac voltages, rectification is necessary

C. dc as well as ac voltage

The main function of the iron core on a transformer is to A. provide strength to the windings B. to decrease the hysteresis losses C. decrease the reluctance of the magnetic path D. reduce eddy current losses

C. decrease the reluctance of the magnetic path

If the resistance in a series RC circuit is increased the magnitude of the phase angle A. increases B. remains the same C. decreases D. changes in an indeterminate manner

C. decreases

In a pure reactive circuit, the power factor is A. lagging B. zero C. leading D. unity

B. zero

The equivalent delta element is given by A. 2R1 B. R/3 C. 3R1 D. R1

C. 3R1

The condition of a secondary cell can be determined by A. its terminal voltage B. the color of the electrolyte C. level of the electrolyte D. the terminal voltage and strength of the electrolyte

D. the terminal voltage and strength of the electrolyte

In a circuit that consist of parallel 12 V source and flows a current of 10 A in each branch A. the total voltage is 24 V B. the total voltage is zero C. the arrangement can be loaded up to 10 A maximum D. the voltage sources connected in parallel can supply a maximum current of 20 A

D. the voltage sources connected in parallel can supply a maximum current of 20 A

The value of form factor for a pure sun wave is A. 1.414 B. 0.701 C. 0.637 D. 1.11

D. 1.11

The value of peak factor for a pure sine wave is A. 1.414 B. 0.707 C. 0.637 D. 1. 11

A. 1.414

Transformers are rated in A. KW B. KV C. KWh D. KVA

D. KVA

The form factor of dc supply voltage is always A. Infinite B. zero C. 0.5 D. unity

D. unity

The economical section of a feeder can be obtained by applying A. ohm's law B. Faraday's law C. Lenz's law D. Kelvin's law

D. Kelvin's law

The capacitor of power factor correction are rated in terms of A. voltage B. VA C. KW D. KVAR

D. KVAR

Regarding Thevenin's equivalent, which of the following is not correct? A. The voltage source in the Thevenin equivalent circuit is the open circuit voltage of the network when load is disconnected B. The Thevenin equivalent resistance is the resistance of the network when all voltage sources are short circuited C. The Thevenin equivalent resistance is calculated when all voltage sources are open circuited D. Thevenin equivalent is the voltage equivalent of the network

C. The Thevenin equivalent resistance is calculated when all voltage sources are open circuited

Which of the following statement is true for a series RLC circuit tuned at resonant frequency A. the voltage across C > applied voltage B. The voltage across L > applied voltage C. The voltage across L and C > applied voltage D. the voltage across both L and C < applied voltage

C. The voltage across L and C > applied voltage

What is the typical use of an autotransformer? A. Toy transformer B. Control transformer C. Variable transformer D. Isolating transformer

C. Variable transformer

Which of the following equipment is not a part of megger? A. hand crank B. moving-coil meter C. a coil of high inductance D. gear box generator

C. a coil of high inductance

Norton's theorem reduces a two terminal network to A. a constant voltage source and an impedance in parallel B. a constant voltage source and an impedance in series C. a constant current source and an impedance in parallel D. a constant current source and an impedance in series

C. a constant current source and an impedance in parallel

To increase the range of a voltmeter A. a low resistance is connected in series B. a low resistance is connected in parallel C. a high resistance is connected in series D. a high resistance is connected in parallel

C. a high resistance is connected in series

Thevenin's theorem is applicable to network of A. a.c. circuit only B. d.c. circuit only C. a.c. and d.c circuit both D. none of the above

C. a.c. and d.c circuit both

For a three wire dc distributor fed at one end, if the total voltage drop in the neutral is positive, it is A. added to the positive drop B. deducted from the positive drop C. added to the positive drop and deducted from the negative drop D. deducted from the positive drop and added to the negative drop

C. added to the positive drop and deducted from the negative drop

There will ____ be a frequency, called the _____ frequency, at which _____ A. sometimes, natural, XL=Xc B. always, natural, R=0 C. always, resonant, XL=Xc D. sometimes, resonant, R=0

C. always, resonant, XL=Xc

In a balanced three phase star connected circuit, the line voltage are equal A. to the line current B. to the phase voltage C. and so are the line currents D. but the line currents are unequal

C. and so are the line currents

In electroplating, the positive electrode is called A. cathode B. terminal C. anode D. iontrap

C. anode

The breakdown torque of a synchronous motor varies as A. 1/ applied voltage B. 1/ (applied voltage)2 C. applied voltage D. (applied voltage)2

C. applied voltage

The rotating part of a DC motors is known as A. pole B. stator C. armature D. carbon brush

C. armature

Synchronous reactance consists of two components, namely A. armature resistance and leakage reactance B. leakage reactance and fictitious reactance C. armature resistance and fictitious reactance D. leakage reactance and capacitive reactance

C. armature resistance and fictitious reactance

Transmission efficiency increases A. as voltage and power factor both decrease B. as voltage and power factor both increase C. as voltage increases but power factor decreases D. as voltage decreases but power factor increases

C. as voltage increases but power factor decreases

For magnetic blow out of arc, the magnetic field is produced A. in the load circuit B. parallel to the axis of the earth C. at right angles to the axis of the earth D. all of the above

C. at right angles to the axis of the earth

Which of the following helps reducing the effect of armature reaction in dc generator A. compensating windings B. interpoles C. both a and b D. none of the above

C. both a and b

The armature current of the synchronous motor has large values of A. low excitation only B. high excitation only C. both low and high excitation D. normal excitation

C. both low and high excitation

The function of an equalizer ring is A. to avoid an equal distribution of current at the brushes B. to help to get sparkless commutation C. both of these D. none of the above

C. both of these

In a circuit breaker, the current which exist at the instant of contact separation is known as A. restriking current B. surge current C. breaking current D. recovery current

C. breaking current A Merz-Price protection is suitable for A. transformer B. alternators C. transmission lines D. feeders == B. alternators

The dummy coil in dc machines is used to A. eliminate reactance voltage B. eliminate armature reaction C. bring about mechanical balance of armature D. eliminate harmonic developed in the machine

C. bring about mechanical balance of armature

A fuel cell converts _____ energy into electrical energy A. mechanical B. magnetic C. chemical D. solar

C. chemical

Which of the following statement is incorrect? A. whenever the flux linking with the coil or circuit changes, emf is produced B. the direction of the dynamically induced emf can be determined by the flemming's hand rule C. coefficient of coupling for tightly coupled coil is zero D. the coefficient of self-inductance is proportional to the square of number of turns on it

C. coefficient of coupling for tightly coupled coil is zero

In a steam turbine cycle, the lowest pressure occurs in A. turbine inlet B. boiler C. condenser D. superheater

C. condenser

The maximum value of potential gradient in a cable occur in A. outer sheet B. insulation C. conductor D. uniformly all over

C. conductor

The surface integral int E ds is equal to A. (Q1 + Q2 + Q3 + Q4)/eo B. [(Q1 + Q2)-(Q3 + Q4)]/eo C. [(Q1 + Q4)-(Q2 + Q3)]/eo D. (Q2 + Q3)/eo

D. (Q2 + Q3)/eo

The armature magnetic field has effect that A. it demagnetizes or weakens the main flux B. it cross magnetizes or distorts it C. it magnetizes or strengthens the main flux D. (a) and (b)

D. (a) and (b)

A factory takes a load of 1000 KW and have a reactive power of 1000 KVAR, its power factor is A. 0.6 B. unity C. 0.8 D. 0 7

D. 0 7

A 400 kw, 3-phase, 440 v, 50 hz induction motor has a speed of 950 rpm on full load. The machine has 6-poles. The slip of the machine will be A. 0.06 B. 0.04 C. 0.10 D. 0.05

D. 0.05

Energy stored in an inductor is given by A. 2 LI^2 Joules B. 0 Joules C. NO/I Joules D. 0.5 LI^2 Joules

D. 0.5 LI^2 Joules

The power dissipated in an RC circuit with R = 30 ohms, Xc = 40 ohms and E = 100V effective is A. 60 B. 80 C. 100 D. 120

D. 120

What charge would be taken by a practical to 10 microfarad capacitor if connected to a 200 V supply? A. 20 V B. 20 A C. 20 uC D. 2.0 mC

D. 2.0 mC

The insulation resistance of high voltage circuit breaker is A. 1 Kohms B. 10 Kohms C. 20 Mohms D. 2000 Mohms

D. 2000 Mohms

A sphere of one meter radius can attain a maximum potential at A. 1000 V B. 30 kV C. 3 million volts D. 3 kV

D. 3 kV

Power in a three phase star system is equal to A. 3 x VL x IL x power factor B. 3 x VL x Iph x power factor C. 1.732x Vph x lph x power factor D. 3 x Vph x Iph x power factor

D. 3 x Vph x Iph x power factor

A resistance of 4 ohms is connected across 100 V supply. When another R ohm is connected in parallel with 4 ohm, the total current taken from the supply was found to be 50 A. The value of the resistance R is A. 2 ohms B. 3 ohms C. 5 ohms D. 4 ohms

D. 4 ohms

The equation for 25 cycles current sine wave having r.m.s value 30 amperes will be A. 30 sin 25t B. 30 sin 50t C. 42.4 sin [(25pi)t] D. 42.4 sin [(50pi)t]

D. 42.4 sin [(50pi)t]

Twelve wires of the same length and same cross-sectional area are connected in the form of a cube. If the resistance of each wire is R, then the effective resistance between one of the side A and B is A. 4/3 R B. R C. ¾ R D. 5/6 R

D. 5/6 R

A transformer is working at its maximum efficiency. Its iron-loss is 500 watts. Its copper loss will be A. 300 watts B. 250 watts C. 350 watts D. 500 watts

D. 500 watts

In a parallel plate capacitor of capacitance Co the electric field is E. If a dielectric slab with dielectric constant equal to 7 is introduced to fill capacitor completely, induced surface charge will be A. q/7 B. 7q C. 7q/6 D. 6q/7

D. 6q/7

If the no load speed of a squirrel cage induction motor connected to a three phase 50 cycle supply is 740 rpm. The motor has A. 2 poles B. 4 poles C. 6 poles D. 8 poles

D. 8 poles

Electric dc generators have normally an overall efficiency of the order of A. 60-80% B. 75-85% C. 80.90% D. 85-95%

D. 85-95%

The efficiency of a transformer is normally in the range of A. 50% to 70% B. 60% to 75% C. 80% to 90% D. 90% to 98%

D. 90% to 98%

Full load efficiency of the generator A. 68 5% B. 73.5% C. 80.8% D. 92.51%

D. 92.51%

Which of the following circuit breaker can be installed on 400 kV line A. Tank type circuit breaker B. Miniature circuit breaker C. Vacuum circuit breaker D. Air blast circuit breaker

D. Air blast circuit breaker

Which of the following is non-petroleum fuel A. Benzol B. Methyl Alcohol C. Ethyl Alcohol D. All of the above

D. All of the above

On which of the following factors the sensitivity in-accuracy of an instrument does not depend A. Hysteresis or dead bond B. Amplitude distortion C. Frequency response D. All of these

D. All of these

Which of the following affect the capacity of a lead-acid battery? A. Temperature B. Specific gravity C. Discharge time D. All the above

D. All the above

High horse power diesel engines are started by A. self starter B. Cranking C. Battery D. Compressor air

D. Compressor air

Which of the following damping methods is common in moving coil instrument A. Air-damping B. Fluid damping C. Spring damping D. Eddy-current damping

D. Eddy-current damping

Which engine has the highest air fuel ratio? A. Petrol engine B. Gas engine C. Diesel engine D. Gas turbine

D. Gas turbine

The speed of a DC series motor decreases if the flux in the field winding A. remains constant B. increases C. decreases D. none of these Which of the following motors is used to drive the constant speed line shafting lathes, blowers and fans? A. DC shunt motor B. DC series motor C. Cumulative compound motor D. Differential compound motor If the back emf in a dc motor is absent, then A. motor will run at a very high speed B. motor will run at a very low speed C. motor will run at all D. motor will burn

D. motor will burn

To determine the distribution of load at the point of minimum potential, the moments in ampere-meter about the one of the feeding point ....... the moments in ampere meters about the other feeding point. A. should be less than B. should be greater than C. could be equal to D. must be equal to

D. must be equal to

Air used in air-blast circuit breaker A. must have least carbon dioxide B. must be ionized C. must have oil mist D. must be free from moisture

D. must be free from moisture

A magnet is able to attract A. iron, aluminum and brass B. iron, cobalt and zinc C. iron, copper and nickel D. nickel, cobalt and steel

D. nickel, cobalt and steel

Other types of accumulator besides the leads acid type are A. alkaline batteries only B. alkaline and solar batteries C. alkaline and dry batteries D. nickel-cadmium batteries

D. nickel-cadmium batteries

While selecting a gas for circuit breaker, the property of gas that should be considered is A. high dielectric strength B. non-inflammability C. non-toxicity D. none of the above

D. none of the above

In asynchronous motor, as load is applied, the motor takes more armature current because A. back emf decreases causing an increase in motor current B. the rotor strengthens the rotating field causing more motor current C. the rotor by shifting its phase backward causes motor to take more current D. none of these

D. none of these

In power generating stations (Thermal stations) usual number of poles employed in the alternators are A. 24 B. 48 C. 32 D. none of these

D. none of these

In an impulse turbine A. always operates submerged B. makes use of a draft tube C. is most suited for low head installation D. operates by initial complete conversion to kinetic energy

D. operates by initial complete conversion to kinetic energy

The difference between the peak +ve plus value and the peak -ve value of an ac voltage is called the A. maximum value B. average value C. effective value D. peak to peak value

D. peak to peak value

In order to transfer the load from one alternator to another alternator, when they are operating in parallel A. field current is increased B. field current is decreased C. speed is decreased D. prime mover power input is increased

D. prime mover power input is increased

The mass of material deposited over an electrode is A. proportional to the voltage B. proportional to time only C. proportional to the current only D. proportional to the quantity or electricity and electro-chemical equivalent

D. proportional to the quantity or electricity and electro-chemical equivalent

As the load is increased the speed of a dc shunt motor will A. remain constant B. increase proportionately C. increase slightly D. reduce slightly

D. reduce slightly

The speed of a dc shunt motor is required to be more than full load speed. This is possible by A. increasing the armature current B. decreasing the armature current C. increasing the excitation current D. reducing the field current

D. reducing the field current

In synchronous motor, the synchronizing power comes into action when A. rotor speed is equal to synchronous speed B. rotor speed is less than synchronous speed C. rotor speed is more than synchronous speed D. rotor speed is either less or more than synchronous speed

D. rotor speed is either less or more than synchronous speed

If n = number of slots per pole per phase and a = slot angle, the distribution factor is A. n sin a/2 / sin q/2 B. sin n a/2 / n sin a/2 C. sin na/2 / n sin a/2 D. sin na/2 / nsina/2

D. sin na/2 / nsina/2

A material commonly used for shielding or screening magnetism is A. brass B. aluminum C. copper D. soft iron

D. soft iron

The value of mutual inductance in turns of self- inductance of the second coil L1 and L2 is proportional to A. L1*L2 B. L1/L2 C. sqrt(L1/L2) D. sqrt(L1*L2)

D. sqrt(L1*L2)

A certain motor is driven by a 1750 rpm DC shunt motor. If the power supply is to be changed to three phase, 50 cycles, AC the most suitable replacement motor would be A. synchronous motor B. ac commutator motor C. capacitor motor D. squirrel cage induction motor

D. squirrel cage induction motor

The motor in which stator and rotor magnetic field rotate at the same speed is A. induction motor B. reduction motor C. universal motor D. synchronous motor

D. synchronous motor

When the light distribution from a lamp or a lamp and fitting is non-uniform, the correct value of luminous intensity in the particular direction is A. given by inverse law B. given by sine law C. given by the average value D. taken from the polar curve

D. taken from the polar curve

The heat produced at the contact point due to passage of current, will least depend on A. contact resistance B. time during which the current flows C. current flowing D. temperature of surrounding medium

D. temperature of surrounding medium

The permeability of the material means A. strength of permanent magnet B. strength of an electromagnet C. the magnetization left in the iron after exciting field has been removed D. the conductivity of the material for magnetic lines of force

D. the conductivity of the material for magnetic lines of force