ELECS COMBI
For a parallel AC circuit, ___ is used as a reference phasor. A. voltage B. power C. current D. resistance
A. voltage
In the series circuit shown in figure, for series resonance, the value of the coupling coefficient, k will be A. 0.25 B. 0.1 C. 0.5 D. 1
A. 0.25
Find the current i in the circuit shown. A. 0.334 A B. 0.394 A C. 0.424 A D. 0.454 A
A. 0.334 A
The transformer has self-inductances of 1H and 0.60H. One series connection of the windings results in total inductance of 1H. What is the coefficient of coupling? A. 0.387 B. 0.347 C. 0.407 D. 0.430
A. 0.387
What is the nominal open-circuit voltage of silver-cadmium which is a secondary cell? A. 1.1 V B. 1.5 V C. 1.2 V D. 1.35 V
A. 1.1 V
What is the minimum fan-out of TTL? A. 2 B. 10 C. 3 D. 20
A. 2
The electrical energy required to heat a bucket of water to a certain temperature is 2 kWh. If heat losses are 25%, the energy input is A. 2.67 kWh B. 2.5 kWh C. 3 kWh D. 3.5 kWh
A. 2.67 kWh
The package of the resistor is rated at 56 ohms, plus or minus 10 percent. You test them with an ohmmeter, which of the following values indicate a reject? A. 20.0 ohms B. 59.7 ohms C. 53.0 ohms D. 61.1 ohms
A. 20.0 ohms
Determine the maximum power that can be supplied to a load by source with Vth = 120V and Rth = 2.5 ohms. A. 5760W B. 3600W C. 1520W D. 1440W
A. 5760W
Find vo. A. 7.4 V B. 5 V C. 2.4 V D. 12 V
A. 7.4 V
The circuit has a resistance of 1000ohms in parallel with the capacitance of 1000pF. The frequency is 100kHz. If the wattmeter reads a VA power of 88 watts, what is the true power? A. 74.4 W B. 72.6 W C. 76.1 W D. 73.3 W
A. 74.4 W
Which thyristor conducts current in both directions when turned on? A. Diac B. Quadrac C. SCR D. SCS
A. Diac
Which, if any, of the following conditions may cause a capacitor to suffer power losses? A. Dielectric hysteresis B. Plate loading C. Plate heating D. None of the above
A. Dielectric hysteresis
For normal operation of a transistor, what is the bias of the emitter-base junction and base-collector junction? A. Forward; reverse B. Reverse; forward C. Forward; forward D. Reverse; reverse
A. Forward; reverse
A dc electromagnet A. Has constant polarity B. Require a core with high retentivity C. Will not attract or repel a permanent magnet D. Require a core with low retentivity
A. Has constant polarity
What drives low-speed alternators? A. Hydraulic turbines B. Steam engines C. Steam turbines D. Diesel engines
A. Hydraulic turbines
For an p channel JFET, Vgs may never be A. Negative B. Positive C. Zero D. Dependent on the application of the device
A. Negative
Valence orbit is the other term for what? A. Outer orbit B. 4th orbit C. 3rd orbit D. 2nd orbit
A. Outer orbit
Which of the following is four-layer diode with an anode gate and a cathode gate? A. SCS B. SBS C. SCR D. SUS
A. SCS
What type of secondary cell can be recharged but with an electrolyte that cannot be refilled? A. Sealed rechargeable cell B. Sealed secondary cell C. Leclanche cell D. Alkaline cell
A. Sealed rechargeable cell
A device that displays a representation of the signal level in audio equipment. A. VU meter B. ESR meter C. LCR meter D. Psophometer
A. VU meter
A device that can characterize active devices such as transistors and amplifiers using S-parameters, as long as they are operating in their linear mode of operation. A. Vector Network analyzer B. Spectrum analyzer C. Vectorscope D. Sweep generator
A. Vector Network analyzer
GaAs is a/an A. compound B. element C. conductor D. gas
A. compound
A wire of one kilometer length has a resistance of 20 ohms, if the length is halved, then the new resistance is ___________ the original resistance A. half B. twice C. one-fourth D. three times
A. half
When the collector resistor in a common emitter amplifier is increased in value the voltage gain A. increases B. remain the same C. decreases D. becomes erratic
A. increases
When the net reactance in a series coil-capacitor circuit is zero at frequency f, the nature of its reactance of frequency 2f is A. inductive B. resistive C. capacitive D. infinite
A. inductive
An alternating current whose average value is 1A will produce _____________ 1A dc under similar conditions A. less heat than B. the same heat as C. more heat than D. extreme heat than
A. less heat than
A 90A current flows into two parallel resistors having resistance of 12ohms and 24ohms. Find the current in the 24ohms resistor. A. 24 A B. 60 A C. 30 A D. 90 A
C. 30 A
Pulse width measurements on the oscilloscope are normally made at: A. 50% amplitude B. 80% amplitude C. 90% amplitude D. 70% amplitude
C. 90% amplitude
What is the temperature coefficient of resistance of Eureka? A. Infinity B. Negative C. Almost zero D. Positive
C. Almost zero
An IGBT is generally used in A. Low-power applications B. RF applications C. High-voltage applications D. Low-current applications
C. High-voltage applications
What are the majority current carriers in a PNP transistor? A. Electrons B. N-type C. Holes D. PN-type
C. Holes
A device that measure illuminances by using the light sensor of the device. A. VU meter B. ESR meter C. Lux meter D. Psophometer
C. Lux meter
A common emitter amplifier has A. More current gain than common base or common collector B. More voltage gain than common base or common collector C. More power gain than common base or common collector D. Highest input impedance of the three amplifier configurations
C. More power gain than common base or common collector
In a JFET, as external bias applied to the gate is increased A. Channel resistance is decreased B. Drain current is increased C. Pinch-off voltage is reached at lower values of Id D. Size of depletion regions is reduced
C. Pinch-off voltage is reached at lower values of Id
The superposition theorem is used when the circuit contains ____________. A. a single voltage source B. passive elements only C. a number of voltage sources D. active elements only
C. a number of voltage sources
An oscillator might fail to start for any of the following reasons except: A. low power supply voltage B. low stage gain C. in-phase feedback D. very low output impedance
C. in-phase feedback
As the deflection of the moving system increases, the controlling torque in an indicating instrument. A. remains the same B. decreases C. increases D. becomes zero
C. increases
A wire 50 m in length and 2 mm^2 in cross section has a resistance of 0.56 ohms. A 100-m length of wire of the same material has a resistance of 2 ohms at the same temperature. Find the diameter of this wire. A. 1.0 mm B. 1.2 mm C. 1.4 mm D. 1.8 mm
B. 1.2 mm
A wire 50m in length and 2mm^2 in cross section has a resistance of 0.56ohms. A 100m length of wire of the same material has a resistance of 2ohms at the same temperature. Find the diameter of this wire. A. 1.8 mm B. 1.2 mm C. 1.4 mm D. 1.0 mm
B. 1.2 mm
Calculate the output voltage for resistor components of value Rf=470kohms, R1=4.3kohms, R2=33kohms and R3=33kohms for an input of 80uV. A. 1.23V B. 1.78V C. 2.11V D. 2.34V
B. 1.78V
Convert BA223C to binary A. 1011101000100011001111 B. 1011101000100010001111 C. 1011101001100010001111 D. 1011111000100010001111
B. 1011101000100010001111
In an astable multivibrator A. B = 1 B. BA = 1 C. B > 1 D. B < 1
B. BA = 1
What is the most commonly used method of speed control of a dc motor? A. By varying voltage applied to the motor B. By varying field strength C. By varying effective number of conductors in series D. By varying armature circuit resistance
B. By varying field strength
As a frequency of an AC wave gets lower, the value of XL for particular coil: A. Increases B. Decreases C. Stays the same D. Depends on the voltage
B. Decreases
Electrons are never found in which of the following bands? A. Energy band B. Forbidden band C. Valence band D. Conduction band
B. Forbidden band
The junction FET, the control electrode is usually the: A. Source B. Gate C. Emitter D. Drain
B. Gate
Equivalent circuit model commonly used in small signal analysis at high frequencies A. Ideal model B. Hybrid-pi or Giacoletto C. H-parameters D. Ebers-Moll
B. Hybrid-pi or Giacoletto
When a transistor is conducting as much as it possibly can, it is said to be: A. In cutoff B. In saturation C. Forward-Biased D. In avalanche
B. In saturation
The device that may convert the captured data into timing diagrams, protocol decodes, state machine traces, assembly language, or may correlate assembly with source-level software. A. Oscilloscope B. Logic analyzer C. RF meter D. Spectrum analyzer
B. Logic analyzer
Which of the following does not affect resistance? A. Resistivity B. Mass C. Cross-sectional area D. Length
B. Mass
In the tunnel diode, the tunneling current is at what level when the forbidden gap of the N-type material is at the same energy level as the empty states of the P-type material? A. Equal to forbidden B. Minimum C. Maximum D. half of the forbidden
B. Minimum
A voltage applied to a PN junction so that it will increase the junction barrier and offer a high resistance to current flow is called what type of bias? A. Direct B. Reverse C. Forward D. Indirect
B. Reverse
Which motor has the best speed regulation? A. Series B. Shunt C. Commulatively compounded D. Differentially compounded
B. Shunt
Which of the following is not a secondary cell? A. Silver-zinc B. Silver oxide C. Nickel-iron D. Lead-acid
B. Silver oxide
Under what condition does resonance occur in an electrical circuit? A. When the power factor is at a maximum B. When inductive and capacitive reactances are equal C. labo D. labo
B. When inductive and capacitive reactances are equal
In an RLC series circuit, the circuit frequency is above the resonant frequency, then A. Xc = XL B. Xc < XL C. Xc > XL D. Z = R
B. Xc < XL
In an RLC series circuit, the circuit frequency is below the resonant frequency, then A. Z = R B. Xc > XL C. Xc = XL D. Xc < XL
B. Xc > XL
A frequency synthesizer makes use of A. the hexidecimal numbering B. a divider C. an or gate D. an octal numbering system
B. a divider
________________ is called a astable multivibrator circuit A. an NAND gate B. a flip-flop C. an XOR gate D. a clock
B. a flip-flop
In the voltage divider network, the total resistance A. should be large to minimize current drain B. should be as small as the power supply will allow C. is not important D. should be such that the current is kept to 100mA
B. should be as small as the power supply will allow
A small-signal amplifier A. always has an output signal in the mV range B. uses only a small portion of its load line C. goes into saturation once on each input cycle D. is always a common-emitter amplifier
B. uses only a small portion of its load line
When two in-phase sine waves that have identical frequency and amplitude are added together, then the result is a sine wave with ___________ the amplitude of either. A. half B. four times C. twice D. one-fourth
C. twice
Dynamic gates driven multiple-input static CMOS gates are susceptible to A. Hot spots B. Minority carrier injection C. Leakeage D. Back-end coupling
D. Back-end coupling
Which is the most suitable for punch presses? A. Shunt motor B. Differentially compounded motor C. Series motor D. Cumulatively compounded motor
D. Cumulatively compounded motor
Find the current I in the circuit shown. A. 0.234 A B. 0.394 A C. 0.334 A D. 0.424 A
C. 0.334 A
A certain class A power amplifier has a Vcbo=12 V and Icq=1 A. The power output is A. 6 W B. 1 W C. 12 W D. 0.707 W
C. 12 W
What is a typical light-to-dark resistance ratio for a photocell? A. 1:100 B. 1:2000 C. 1:1000 D. 1:5000
C. 1:1000
The brush voltage drop in a dc machine is about how much? A. 0.1 V B. 10 V C. 2 V D. 20 V
C. 2 V
The rms value of the waveform of the figure is A. 3.266 A B. 4 A C. 2.887 A D. 1.43 A
C. 2.887 A
The reason why alternating current can induce voltage is A. It has a high peak value B. It has a stronger magnetic field than direct current C. It has a constant magnetic field D. It has a varying magnetic field
D. It has a varying magnetic field
The state of SR latch when both signals are " 1 " A. Hold state B. Set C. Reset D. Not allowed
D. Not allowed
Process of growing a thin layer of silicon dioxide over a semiconductor. A. Photolithographic process B. Isolation C. Metallization D. Oxidation
D. Oxidation
The principal disadvantage of the voltage multiplier A. Excessive current B. Excessive voltage C. Insufficient rectification D. Poor regulation
D. Poor regulation
Which of the following is NOT one of the three distinct regions in the characteristic curve of a diode? A. Forward bias region B. Reverse bias region C. Breakdown region D. Saturation region
D. Saturation region
A __ is like two parallel SCRs having a common gate and connected opposite directions A. UJTs B. PUTs C. Diacs D. Triacs
D. Triacs
What is initial charge? A. Used in emergency only B. Used periodically as part of a maintenance routine C. Used to keep a battery at full charge while the battery is idle D. Used after electrolyte is added to a dry shipped battery
D. Used after electrolyte is added to a dry shipped battery
Which of these does not satisfy D-MOSFET depletion mode operation? A. When Vgs = 0V, Id = Idss B. When Vgs < 0V, Id < Idss C. When Vgs > 0V, Id > Id D. When Vgs < Vt, Idss = 0
D. When Vgs < Vt, Idss = 0
How can a class amplifier be made linear? A. by reducing the bias B. by increases the drive C. by adding two transistor in push-pull D. a class-C amplifier cannot be made linear
D. a class-C amplifier cannot be made linear
As the capacitor plate area increases, all things being equal A. the capacitance decreases B. the capacitance do not change C. the voltage-handling ability increases D. the capacitance increases
D. the capacitance increases
Why is a two-pole magnetic field setup around a coil? A. because separate lines of magnetic force link and combine their effects B. because concentric lines of force cross at right angles and combine C. because lines of force are separated and bent at the coil ends D. because separate lines of force are attracted to the two poles of the coil
A. because separate lines of magnetic force link and combine their effects
If the inductance is decreased, the impedance of the circuit containing a resistor, a capacitor and an inductor connected in series to an ac source A. decreases B. increases C. decreases or increases D. decreases, increases or remains the same
A. decreases
The area of capacitor plates increases two times, then its capacitance A. increases two times B. increases four times C. decreases two times D. decreases four times
A. increases two times
If the capacitor has a negative temperature coefficient A. its value decreases as the temperature rises B. its value increases as the temperature rises C. its value does not change with temperature D. it must be connected with the correct polarity
A. its value decreases as the temperature rises
Which of the following is the main function of a battery? A. To provide a source of steady dc voltage of fixed polarity B. To provide a source of steady dc voltage of variable polarity C. To provide a source of variable dc voltage of fixed polarity D. To provide a source of variable dc voltage of variable polarity
A. To provide a source of steady dc voltage of fixed polarity
The state of clocked JK flip-flop when Q=1, J=1 and K=1 is A. Toggle B. Set C. Reset D. Not allowed
A. Toggle
A long cylindrical solenoid with 200 turns/cm carries a current of 4.0 amps. The diameter of the solenoid is 0.4 cm and the length is 8.0 cm and the mass of the moon is 7.35E22 kg. What is the magnetic field inside the solenoid? A. 0.1005 T B. 0.0105 T C. 1.0500 T D. 10.050 T
A. 0.1005 T
Rise time measurements are most commonly made from the following amplitudes: A. 10-90% B. 20-80% C. 0-100% D. 30-70%
A. 10-90%
In an emitter follower, we employ __________ negative current feedback. A. 100% B. 50% C. 75% D. 25%
A. 100%
What is the nominal output of an automotive battery having six lead-acid cells in series? A. 12 V B. 6 V C. 24 V D. 3 V
A. 12 V
Electrons pass to the right through a wire cross section at the rate of 5.2 x 10^21 electrons per minute. What is the current in the wire? A. 13.9 A B. 12.9 A C. 13.3 A D. 14.3 A
A. 13.9 A
It is used to display the phase of the colors in color TV A. Vectorscope B. Network analyzer C. Spectrum analyzer D. Sweep generator
A. Vectorscope
Which dynamometer type has uniform scale? A. Wattmeter B. Ammeter C. Voltmeter D. Ohmmeter
A. Wattmeter
How many coulombs are delivered by a storage battery in 24 hours if it is supplying current at the rate of 3 A? A. 2.592 x 10^5 C B. 2.592 x 10^8 C C. 2.592 x 10^4 C D. 2.592 x 10^10C
A. 2.592 x 10^5 C
An amplifier has a current gain of 240 and input impedance of 15 kohms without feedback. If negative current feedback (mi=0.015) is applied, what will be the input impedance of the amplifier? A. 3.26 kohms B. 3.82 kohms C. 2.26 kohms D. 3.62 kohms
A. 3.26 kohms
The resistance of a certain wire is 20ohms. Another wire of the same material and at the same temperature has a diameter one-third as great and a length twice as great. Find the resistance of the second wire. A. 360 ohms B. 40 ohms C. 180 ohms D. 240 ohms
A. 360 ohms
Two series connected 7 H inductors are adjacent to each other. Their coefficient of coupling 0.64. What is the value of mutual inductance? A. 4.48 H B. 44.8 H C. 0.448 H D. 448 H
A. 4.48 H
Transient period is considered over after A. 5 Tau B. 100 Tau C. 1 Tau D. 6 Tau
A. 5 Tau
An ac voltage of 350 volts effective can be safely applied to a capacitor with which of the following working voltages? A. 550 volts B. 350 volts C. 400 volts D. 250 volts
A. 550 volts
In two-phase generators, the electrical displacement between the two phases or windings is _____________ electrical degrees. A. 90 B. 180 C. 120 D. 360
A. 90
Why a cumulatively compounded motor does not run at dangerous speed at light loads? A. Because of the presence of shunt winding B. Because of the presence of interpoles C. Because of the presence of series D. Because of the presence of compensating windings
A. Because of the presence of shunt winding
In a circuit where the AC voltage and current are out of phase, how can the true power be determined? A. By multiplying the apparent power times the power factor B. By subtracting the apparent power from the power factor C. By dividing the apparent power by the power factor D. By multiplying the RMS voltage times the RMS current
A. By multiplying the apparent power times the power factor
Which class of amplifier has the highest linearity and least distortion? A. Class A B. Class C C. Class B D. Class AB
A. Class A
A moving system force in analog instruments which causes the moving system to deflect from its zero position. A. Deflecting force B. Damping force C. Return-to-zero force D. Controlling force
A. Deflecting force
What is basically a two-terminal parallel-inverse combination of semiconductor layers that permits triggering in either direction? A. Diac B. Quadrac C. Triac D. Shockley diode
A. Diac
When you use the right-hand rule for motors, what quantity is indicated by the extended forefinger? A. Direction of flux North to South B. IDK C. Direction of current D. Direction of motion
A. Direction of flux North to South
What is the rms value of a square wave? A. Equals its peak value B. Equals its peak-to-peak value C. Peak divided by square root of two D. Peak divided by pi
A. Equals its peak value
What does K shell mean? A. First orbit B. 3rd orbit C. 2nd orbit D. 4th orbit
A. First orbit
What is the voltage regulation of an alternator with a power factor of 0.8 lagging compared at unity power factor? A. Greater than B. Smaller than C. The same as D. 100%
A. Greater than
If the EMF of one volt is placed across a resistance of two ohms, then the current is: A. Half an ampere B. One ampere C. Two ampere D. One ohm
A. Half an ampere
What does HDL stands for A. Hardware Description Language B. Hardware Data Language C. Hardware Data Logic D. Hardware Date Lullaby
A. Hardware Description Language
The geomagnetic field A. Is what makes a compass work B. Runs exactly through a geomagnetic pole C. Is what makes an electromagnetic work D. Makes the earth like a huge horseshoe magnet
A. Is what makes a compass work
What is the disadvantage of impedance matching? A. It gives distorted output B. It requires a transformer C. It gives low power output D. It is expensive
A. It gives distorted output
In IGBT, the saturation voltage is A. Low B. High C. Medium D. Very High
A. Low
A universal gate is a A. NOR gate B. AND gate C. OR gate D. NOT gate
A. NOR gate
The state of SR latch when both signals are " 0 ". A. No change B. Set C. Reset D. Not allowed
A. No change
What is a three terminal device used to control large current to a load? A. SCR B. GTO C. SCS D. Thyristor
A. SCR
Find the voltage (V), if the current (I) of the source is 3A
155.65 V
Which of the following voltage could normally represent a 1 in a positive logic? A. 0 V B. +4 V C. +1 V D. +12 V
B. +4 V
In a class C power amplifier the input signal has a frequency of 250 kHz. If the collector current pulses are 0.1 us wide, what is the duty cycle of current waveform? A. 50% B. 2.5% C. 25% D. 0.25%
B. 2.5%
You have an unlimited supply of 1 W, 100 ohms resistors. You need to get a 100 ohms, 10 W resistor. This can be done most cheaply by means of series-parallel matrix of: A. 3 x 3 resistors B. 4 x 4 resistors C. 4 x 3 resistors D. 2 x 5 resistors
B. 4 x 4 resistors
The nine's complement of 3 is A. 8 B. 6 C. 3 D. 9
B. 6
A short circuit across a current source draws 15A. If a 10 ohms resistor across the source draws 13A, what is the internal resistance of the source? A. 55 ohms B. 65 ohms C. 60 ohms D. 70 ohms
B. 65 ohms
Calculate the efficiency of a class B amplifier for a supply voltage of Vcc=24V with peak output voltages of Vl(p)=22V A. 90% B. 72% C. 87% D. 75%
B. 72%
The impedance of R-C series circuit is 100ohms. If circuit current leads the applied voltage by 60 degrees the capacitive reactance is ___________ A. 50ohms B. 86.6ohms C. 70.7ohms D. 200ohms
B. 86.6ohms
How are fixed capacitors classified? A. By their plate size B. By their dielectric materials C. By the thickness of their dielectric materials D. By the thickness of their conductors
B. By their dielectric materials
A hot-wire ammeter A. Measure electrical energy B. Can measure ac as well as dc C. Can indicate very low voltages D. Works only when current flows in one direction
B. Can measure ac as well as dc
These are current measurement without breaking circuits can be used for voltage, temperature and other measurements. A. LCR meter B. Clamp meters C. EMF meter D. Psophometer
B. Clamp meters
Push-pull is almost always used with A. Class A B. Class B C. Class C D. All of the above
B. Class B
The voltmeter should generally have: A. Low internal resistance B. Large internal resistance C. Maximum possible sensitivity D. Able to withstand large currents
B. Large internal resistance
One of the other input can be true for the output to be false. A. AND B. NOR C. OR D. XNOR
B. NOR
Which of the following types of routine charges follows the nameplate data in restoring a battery to its charged condition during the ordinary cycle of operation? A. Initial B. Normal C. Floating D. Fast
B. Normal
One or the other input can be true for the output to be true. A. AND B. OR C. NOR D. XNOR
B. OR
A phase difference of 540 degrees would more often be spoken as A. An offset of more than one cycle B. Phase opposition C. A cycle and a half D. 1.5 Hz
B. Phase opposition
The rate of doing work is referred to as A. Energy B. Power C. Force D. Acceleration
B. Power
What is usually employed at the output stage of an amplifier? A. Class A power amplifier B. Push-pull amplifier C. Pre-amplifier D. Differential amplifier
B. Push-pull amplifier
If all the delta connected resistor are identical, what is the equivalent value of the resistor in WYE connection? A. R B. R/3 C. R/2 D. R/4
B. R/3
In a vacuum cleaner, what motor is generally used? A. Shunt B. Series C. Cumulatively compounded D. Differentially compounded
B. Series
The common 9-V flat battery for transistor radio has how many cells connected in series? A. Twelve B. Six C. Three D. Nine
B. Six
The magnetism of ferromagnetic materials, such as iron, has its origin in the intrinsic magnetic moment of electrons that is associated with their A. Orbital angular momentum B. Spin angular momentum C. Electric charge D. Being magnetically soft
B. Spin angular momentum
The pointer of an indicating instrument is generally made of A. copper B. aluminum C. silver D. gold
B. aluminum
When a differential amplifier is operated single-ended, A. the output is grounded B. one input is grounded and a signal is applied to the other C. both inputs are connected together D. the output is not inverted
B. one input is grounded and a signal is applied to the other
It is method of stabilizing the voltage gain. A. darlington pair B. swamping C. differential mode D. common mode
B. swamping
It is a thin polished slice of semiconductor crystal on which integrated circuit can be fabricated often in duplicate, for cutting into individual slice. A. silicon B. wafer C. indium D. gallium
B. wafer
The ac load line differs from the dc load line because A. the effective ac collector resistance is less than the dc collector resistance B. the effective ac collector resistance is less than the ac collector resistance C. the effective dc collector resistance is less than the dc collector resistance D. the effective ac collector resistance is greater than the dc collector resistance
A. the effective ac collector resistance is less than the dc collector resistance
A 4-layer diode turns on when the anode-to-cathode voltage exceeds A. the forward-breakover voltage B. the forward-blocking voltage C. 0.7V D. the gate voltage
A. the forward-breakover voltage
The operating point is generally located at ___________ of dc load line in class A operation. A. the middle B. cut-off point C. saturation point D. end point
A. the middle
VL = Vc in a series RLC circuit when A. the value of the impedance is minimum B. the power factor is zero C. the current leads the total voltage by 90 degrees D. the total voltage is zero
A. the value of the impedance is minimum
The PUT is A. trigger on and off by the gate-to-anode B. much like the UJT C. not a four-layer diode D. not a thyristor
A. trigger on and off by the gate-to-anode
Often used to characterize two-port networks such as amplifiers and filters, but they can be used on networks with an arbitrary number of ports. A. vector network analyzer B. spectrum analyzer C. vectorscope D. sweep generator
A. vector network analyzer
The input resistance of a common-base amplifier is A. very low B. very high C. the same as a CE D. the same as a CC
A. very low
For a series AC circuit, ___ is not used as a reference phasor. A. voltage B. impedance C. current D. conductance
A. voltage
As applied to a series RLC circuit, bandwidth means A. the frequency range for maximum power transfer B. the difference between the highest and lowest frequencies of the oscillator C. the separation of the half-power points D. the frequency at which XL = Xc
C. the separation of the half-power points
In order to have more voltage gain from a transistor amplifier the transistor used should have A. thin collector B. wide emitter C. thin base D. thin emitter
C. thin base
In the circuit of figure the function of resistor R and diode D are A. to limit the current and to protect LED against over voltage B. to limit the voltage and to protect LED against over current C. to limit the current and protect LED against reverse breakdown voltage D. none of the above
C. to limit the current and protect LED against reverse breakdown voltage
Two coils have their axes perpendicular to each other. The coefficient of coupling k is A. 1 B. 0.5 C. more than 0 but less than 1 D. 0
D. 0
What is the complex impedance of a circuit with an absolute resistance of 300 ohms? A. 0 + j300 ohms B. 0 - j300 ohms C. 300 + j90 ohms D. 300 + j0 ohms
D. 300 + j0 ohms
How long can 12V car battery supply 240A to a starter motor if the battery has 6 x 10^6 J of chemical energy that can be converted to electrical energy? A. 31.1 min B. 34.3 min C. 33.3 min D. 34.7 min
D. 34.7 min
Two phasors having rms values V1 and V2 which are added to give a phasor having rms value V3. V3 is maximum if phase angle between V1 and V2 is A. 90 degrees B. 270 degrees C. 180 degrees D. 360 degrees
D. 360 degrees
What maximum power can a silicon transistor (Tjmax= 200degC) dissipate into free air at an ambient temperature of 80degC? A. 0.5W B. 1W C. 2W D. 3W
D. 3W
Si transistor of following figure has a = 0.9 and Ice = 0, Vee = 5V and Vcc = 13V, then Re will be if Ieq = 1mA A. 3kohms B. 5kohms C. 4kohms D. 4.3kohms
D. 4.3kohms
Determine the Thevenin equivalent voltage. A. 60V B. 50V C. 10V D. 40V
D. 40V
A frequency synthesizer makes use of A. An OR gate B. An octal numbering system C. The hexadecimal numbering D. A divider
D. A divider
A thyristor has a maximum allowable junction temperature of 120 C and the ambient temperature is 40 C. If thermal resistance is 1.6 C/W, what is the maximum allowable internal power dissipation? A. 20 W B. 92 W C. 50 W D. 128 W
C. 50 W
In a common-emitter amplifier with voltage-divider bias, Rin(base)=68 kohms, R1=33 kohms, and R2=15 kohms. The total input resistance is A. 68 kohms B. 22.2 kohms C. 8.95 kohms D. 12.3 kohms
C. 8.95 kohms
When an SCR is forward biased, what is needed to cause it to conduct? A. A cathode B. An anode signal C. A gate signal D. A P-channel signal
C. A gate signal
The channel in a zero-biased JFET is normally: A. Pinched off B. Somewhat open C. All the way open D. Of P-type semiconductor
C. All the way open
Plastic dual-in-line for insertion into sockets has a package suffix code of A. N B. P C. Both A and B D. J
C. Both A and B
If the pointer of an indicating instrument is in motion, then what opposes deflecting torque? A. Controlling torque B. Damping torque C. Damping and controlling torques D. Frictional torque
C. Damping and controlling torques
An IGBT is generally used in A. Low-power applications B. RF applications C. High-power applications D. Low-current applications
C. High-power applications
The state of clocked JK flip-flop when Q=1, J=1 and K=0 is A. no change B. low C. high D. 0
C. high
What are the two junctions of a transistor? A. Emitter-base and emitter-collector B. Emitter-collector and base-collector C. Emitter-base and collector-emitter D. Emitter-base and base-collector
D. Emitter-base and base-collector
The junction FET, the control electrode is usually the A. Source B. Emitter C. Drain D. Gate
D. Gate
The formula 2pifL is used to determine what electrical quantity? A. Resistance B. Inductance C. Counterreaction D. Inductive reactance
D. Inductive reactance
Selenium works especially well in A. high-frequency detectors B. radio-frequency power amplifiers C. photocells D. voltage regulators
C. photocells
The circuit efficiency of a class A amplifier can be increased by using A. Low dc power input B. Direct-coupled load C. Low-rating transistor D. Transformer-coupled load
D. Transformer-coupled load
The low power factor of the circuit means that it will A. draw more active power B. less line current C. cause less voltage drop in the line D. draw more reactive power
D. draw more reactive power
In small inductance: A. energy is stored and release slowly B. the current flow is always large C. the current flow is always small D. energy is stored and release quickly
D. energy is stored and release quickly
In a RAM: A. it's easy to get data out and hard to put it in B. it's hard to get data out and easy to put it in C. it's hard to get data out and put it in D. it's easy to get data out and put it in
D. it's easy to get data out and put it in
To measure power-supply voltage being used by a circuit, a voltmeter A. Is placed in series with the circuit that works from the supply B. Is placed between the positive pole of the supply and the circuit working from the supply C. Is placed between the negative pole of the supply and the circuit working from the supply D. Is placed in parallel with the circuit that works from the supply
D. Is placed in parallel with the circuit that works from the supply
What is the reason why a common collector is used for impedance matching? A. Its output impedance is very high B. Its output impedance is very low C. Its input impedance is very low D. Its input impedance is very high
D. Its input impedance is very high
A four-layer semiconductor device that conducts current in one direction when activated by sufficient amount of light. A. Optical coupler B. Photodarlington C. Phototransistor D. LASCR
D. LASCR
The voltmeter should generally have: A. Low internal resistance B. Maximum possible sensitivity C. Able to withstand large currents D. Large internal resistance
D. Large internal resistance
One of the most sensitive elements of semiconductor materials is galena. Galena is a crystalline form of what material? A. Krypton B. Strontium C. Bismuth D. Lead sulfide
D. Lead sulfide
When R=0 in the series RLC circuit, but the net reactance is not zero, the impedance vector: A. Always points straight up B. Always points straight down C. Always points straight towards the right D. None of the above
D. None of the above
What is the term for the time it takes for a charged capacitor in an RC circuit to discharge to 36.8% of its initial value of stored charge? A. One discharge period B. An exponential discharge rate of one C. A discharge factor of one D. One time constant
D. One time constant
The oscillating frequency of the quartz crystal can be varied slightly by: A. Changing the bias on the transistor B. Changing the voltage across each one C. Reversing the power supply polarity D. Placing a small variable capacitor across the crystal
D. Placing a small variable capacitor across the crystal
The bandwidth of a class C amplifier decreases when the A. Resonant frequency increases B. XL decreases C. Load resistance decreases D. Q increases
D. Q increases
Which of the following does NOT a main CMOS technology? A. Twin-well process B. N-well process C. Triple-well process D. Quad-well process
D. Quad-well process
What is the value of resistor with color bands from left: Red-Blue-Gold-Silver A. R=2.7 +- 10% B. R=3.6 +- 10% C. R=2.8 +- 10% D. R=2.6 +- 10%
D. R=2.6 +- 10%
A CMOS integrated circuit A. Requires considerable power to function B. Need very high voltage C. Can only work at low frequencies D. Susceptible to damage to static
D. Susceptible to damage to static
What happens to photoconductive material when light strikes on it? A. The conductivity of the material decreases B. Nothing important happens C. The conductivity of the material stays the same D. The conductivity of the material increases
D. The conductivity of the material increases
What is the characteristic of the current flow in a parallel R-L-C circuit at resonance? A. The current circulating in the parallel elements is zero B. The current circulating in the parallel elements is dc C. The current circulating in the parallel elements is at a maximum D. The current circulating in the parallel elements is at a minimum
D. The current circulating in the parallel elements is at a minimum
A 4-layer diode turns on when the anode to cathode voltage exceeds A. 0.7 V B. The gate voltage C. The forward-blocking voltage D. The forward-breakover voltage
D. The forward-breakover voltage
The output of a certain two-supply class B push-pull amplifier has a Vcc of 20 V. If the load resistance is 50 ohms, the value of I(sat) is A. 5 mA B. 40 mA C. 4 mA D. 0.4 mA
400 mA or B. 40 mA nalang kasi yun malapit
In Boolean algebra, a high signal added to another high signal is A. 0 B. 1 C. 10 D. 11
A. 0
An ac circuit draws 5A current and consumes 1000W power. What is the power factor? A. 0.91 B. 0.9 C. 0.82 D. 0.88
A. 0.91
A coil is supplied with 200V and takes a current of 2A at 45 degrees lagging. The Q of the coil is A. 1 B. 25 C. 10 D. 100
A. 1
How many electrons are there in the fourth orbit of a copper atom? A. 1 B. 3 C. 2 D. 4
A. 1
What is the typical turn-on time of an SCR? A. 1 us B. 10 us C. 5 us D. 3 us
A. 1 us
A material with an excess of 25 x 10^18 electrons loses 6.25 x 10^18 electrons. The excess electrons are then made to flow past a given point in 2s. Find the current produced by the resultant electron flow. A. 1.5A B. 1.2A C. 2.1A D. 2.5A
A. 1.5A
Calculate the harmonic distortion components for an output signal having fundamental amplitude of 2.1V, second harmonic amplitude of 0.3V, third harmonic component of 0.1V, and fourth harmonic component of 0.05V A. 14.3%,4.8%,2.4% B. 14.3%,4.2%,2.8% C. 12.3%,4.8%,2.4% D. 12.3%,4.2%,2.8%
A. 14.3%,4.8%,2.4%
What is the maximum permissible number of electrons in the third orbit? A. 18 B. 32 C. 8 D. 2
A. 18
A battery with capacity of 100 Ah and 12 volts rating will run an electronic equipment at exactly 20 hours, how much power is needed? A. 60 W B. 10 W C. 20 W D. 30 W
A. 60 W
For a common-emitter amplifier, Rc = 1 kohms, Re = 390 ohms, r'e = 15 ohms, and Bac = 75. Assuming that Re is completely bypassed at the operating frequency, the voltage gain is A. 66.7 B. 2.47 C. 2.56 D. 75
A. 66.7
At what frequency will an inductor of 5mH have the same reactance as a capacitor of 0.1 uF? A. 7.12 kHz B. 7.12 MHz C. 7.12 Hz D. 7.12 GHz
A. 7.12 kHz
In figure, Vbe=0.6 V, B=99, Vcc=20 V, Rb=400 kohms, Rc=5.4 kohms. Then Vc and Ic are A. 9.3 V and 1.98 mA respectively B. 4.6 V and 1.98 mA respectively C. 9.3 V and 0.02 mA respectively D. 4.6 V and 0.02 mA respectively
A. 9.3 V and 1.98 mA respectively
Each stage of a four-stage amplifier has a voltage gain of 15. The overall gain found can be expressed in decibels as A. 94.1 dB B. 35.6 dB C. 47.0 dB D. 69.8 dB
A. 94.1 dB
A CB amplifier has very low input resistance because A. A low emitter ac resistor ra shunts all other resistances B. It handles small input signals C. Emitter bulk resistance is small D. Its base is at ac ground
A. A low emitter ac resistor ra shunts all other resistances
In a negative-logic circuit, what level is used to represent a logic 1? A. A low level B. A positive-transition level C. A negative-transition level D. A high level
A. A low level
Which of the following will not cause a major error in an ohmmeter? A. A small change in the resistance to be measured B. A small voltage between points under test C. A slight change in switchable internal resistance D. A slight error in the range switch selection
A. A small change in the resistance to be measured
What kind of instrument an ammeter is? A. An indicating B. A recording C. An integrating D. A dc meter
A. An indicating
An instrument in which the magnitude of the measured quantity is indicated by means of a pointer. A. Analog instrument B. Digital instrument C. Ammeter D. Voltmeter
A. Analog instrument
Electric field lines start A. At positive charges or at infinity B. At negative charges or infinity C. At infinity and end at positive charges D. Midway between positive charges and negative charges
A. At positive charges or at infinity
For maximum peak-to-peak output voltage, the Q point should be A. At the center of the ac load line B. Near saturation C. Near cutoff D. At the center of the dc load line
A. At the center of the ac load line
When two parallel current-carrying wires have currents in the same direction, the wires A. Attract one another B. Repel one another C. Exert no forces on one another D. Exert equal and opposite repulsive forces on one another perpendicular to the phase of the wires
A. Attract one another
What do you call a group of cells that generate electric energy from their internal chemical reaction? A. Battery B. Power supply C. Regulator D. Solar array
A. Battery
Why carbon brushes are used in a dc machine? A. Because carbon lubricates and polishes the commutator B. Because contact resistance is decreased C. Because carbon is cheap D. Because carbon is abundant
A. Because carbon lubricates and polishes the commutator
What is the reason why electrons are not pulled into the nucleus of an atom? A. Because of the centrifugal or outward force created by their orbital motion B. Because of the force of attraction between them and the nucleus is weak C. Because they are not being attracted by the positive nucleus D. Because of the strong bonding between them that resists any force pulling them towards the nucleus
A. Because of the centrifugal or outward force created by their orbital motion
At some potential, as you increase the reverse bias voltage on a PN junction, the reverse current increases very rapidly. What electronic term is given to this voltage potential? A. Breakdown voltage B. Forward-bias C. Reverse-bias D. Thermal runaway
A. Breakdown voltage
All are through-hole packages types of packages except A. Ceramic package B. Dual in-line package C. Zig-zag in-line package D. Dual in-line package
A. Ceramic package
Pierce oscillator is a derivative of the __________. A. Colpitts oscillator B. Armstrong oscillator C. Clapp oscillator D. Phase-shift oscillator
A. Colpitts oscillator
What transistor configuration has the lowest current gain? A. Common base B. Common collector C. Common emitter D. Emitter-follower
A. Common base
The meter movement in an illumination meter measures: A. Current B. Energy C. Voltage D. Power
A. Current
What is the function of a decade counter digital IC? A. Decode a decimal number for display on a seven-segment LED display B. Produce one output pulse for every ten input pulses C. Produce ten output pulses for every input pulse D. Add two decimal numbers
A. Decode a decimal number for display on a seven-segment LED display
The power gain of an amplifier A. Equals output power divided by input power B. Equals load power C. Is the same as the voltage gain D. Is smaller than the voltage gain
A. Equals output power divided by input power
A thermocouple: A. Gets warm when the current flows through it B. Is a thin, straight, special wire C. Generates dc when expose to the light D. Generates ac when heat
A. Gets warm when the current flows through it
Measured by the output impedance Zo (the driving-point impedance looking into the output port with the load removed) A. Impedance match B. Voltage amplification C. Power amplification D. Power transfer ability
A. Impedance match
In which of the following a transformer will work on? A. In ac only B. In ac as well as dc C. In dc only D. In pulsating dc
A. In ac only
The symbol Icbo signifies the current that flows when some dc voltage is applied A. In the reverse direction to the collector junction with the emitter open-circuited B. In the forward direction to the collector junction with the emitter open-circuited C. In the reverse direction to the emitter junction with the collector open-circuited D. In the forward direction to the emitter junction with the collector open-circuited
A. In the reverse direction to the collector junction with the emitter open-circuited
What is the purpose of the bypass capacitor in a common-emitter amplifier? A. It increases voltage gain B. It decreases voltage gain C. It provides ac grounding D. No effect in the circuit
A. It increases voltage gain
In a chemical cell, what is current? A. It is the movement of positive and negative ions B. It is the movement of positive charges C. It is the movement of positive ions only D. It is the movement of negative ions only
A. It is the movement of positive and negative ions
If the load impedance for the oscillator is too high: A. It's not a cause for worry; it can't be too high B. The frequency might drift C. The power output might be reduce D. The oscillator might fail to start
A. It's not a cause for worry; it can't be too high
A vector is a quantity that has a A. Magnitude and direction B. Resistance and inductance C. Resistance and reactance D. Inductance and reactance
A. Magnitude and direction
When should a fuse be replaced with a higher rated unit? A. Never B. When the original value is not available C. If it blows D. When fuses of the original value are small in size
A. Never
The principal disadvantage of the voltage multiplier A. Poor regulation B. Insufficient rectification C. Excessive current D. Excessive voltage
A. Poor regulation
On combinational circuit design, which of the following have dynamic nodes? A. Pseudo-nMOS B. Complementary Pass Transistor Logic C. LEAP D. Domino
A. Pseudo-nMOS
What component of dielectric current is proportional to the rate of accumulation of electric charges within the dielectric? A. Reactive current B. Apparent current C. Inductive current D. Absorption current
A. Reactive current
A defect than can be described as a pair of vacant lattice sites, an anion site and a cation site. A. Schottky defect B. planer defect C. line defect D. Frenkel defect
A. Schottky defect
What is the other term thermoelectric effect? A. Seebeck effect B. Hall effect C. Photoelectric effect D. Thermal effect
A. Seebeck effect
The first stage of a preamp is A. Small signal B. A tuned RF stage C. Large signal D. A dc amplifier
A. Small signal
The characteristic of UJT that determines its turn-on point. A. Standoff ratio B. DC current ratio C. Trigger current D. Transfer gain
A. Standoff ratio
What happens to photoconductive material when light shines on it? A. The conductivity of the material increases B. The conductivity of the material decreases C. The conductivity of the material stays the same D. The conductivity of the material becomes temperature dependent
A. The conductivity of the material increases
What is the characteristic of the current flow in a parallel R-L-C circuit at resonance? A. The current circulating in the parallel elements is at a minimum B. The current circulating in the parallel elements is at a maximum C. The current circulating in the parallel elements is DC D. The current circulating in the parallel elements is zero
A. The current circulating in the parallel elements is at a minimum
Assuming a power source to have a fixed value of internal impedance, maximum power will be transferred to the load when: A. The load impedance equals the internal impedance of the source B. The load impedance is greater than the source impedance C. The load impedance is less than the source impedance D. The fixed values of internal impedance is not relative to the power source
A. The load impedance equals the internal impedance of the source
Which of the digital IC is least susceptible to noise? A. Transistor-transistor logic B. Base-coupled logic C. Emitter-coupled logic D. N-channel-couple logic
A. Transistor-transistor logic
The ripple frequency of the full-wave rectifier is A. Twice that of the half-wave circuit B. The same as that of the full-wave circuit C. Half that of the half-wave circuit D. One-fourth that from a half-wave circuit
A. Twice that of the half-wave circuit
A volume-enclosing group of atoms that can be used to describe the lattice by repeated translations. A. Unit cell B. Lattice C. Lattice points D. Primitive cell
A. Unit cell
What is fast charge? A. Used in emergency only B. Used periodically as part of a maintenance routine C. Used to keep a battery at full charge while the battery is idle D. Used after electrolyte is added to a dry shipped battery
A. Used in emergency only
A device that can characterize active devices such as transistors and amplifiers using S-parameters, as long as they are operating in their linear mode of operation A. Vector Network analyzer B. Spectrum analyzer C. Vectorscope D. Sweep generator
A. Vector Network analyzer
An OTA is basically A. Voltage-to-controlled amplifier B. Current-to-voltage amplifier C. Current-to-controlled amplifier D. Voltage-to-voltage amplifier
A. Voltage-to-controlled amplifier
What cell is otherwise known as Galvanic cell? A. Voltaic cell B. Secondary cell C. Primary cell D. Solar cell
A. Voltaic cell
Series resonance occurs when A. XL=Xc B. Z=R C. XL=R D. Both A and C
A. XL=Xc and B. Z=R
A class-A circuit would not work well as: A. a television transmitter PA B. a stereo hi-fi amplifier C. a low-level microphone preamplifier D. the first stage in radio receiver
A. a television transmitter PA
The ac system is preferred to dc system because A. ac voltage system can be easily changed B. dc voltage system is not applicable for domestic appliances C. dc systems are very difficult to control D. all systems depend on ac supply
A. ac voltage system can be easily changed
For a UJT, the intrinsic standoff ratio is A. always less than 1 B. always greater than 1 C. equal to 1 D. usually around 1k or so
A. always less than 1
Varactor diodes are commonly used A. as a voltage controlled capacitance B. as a constant current source C. as voltage multiplier D. as a common voltage source
A. as a voltage controlled capacitance
Varactor diodes are commonly used A. as a voltage controlled capacitance B. as a constant current source C. as voltage multiplier D. as a constant voltage source
A. as a voltage controlled capacitance
The magnetic field of a magnetized iron bar when strongly heated A. becomes weaker B. becomes stronger C. reverses in direction D. is unchanged
A. becomes weaker
A hot-wire ammeter: A. can measure ac as well as dc B. can indicate very low voltages C. measure electrical energy D. works only when current flows in one direction
A. can measure ac as well as dc
Asynchronous circuits has no __________ signal A. clock B. event C. pulse D. flop
A. clock
Synchronous circuits that are synchronized to a specific ____________ signal A. clock B. event C. pulse D. flop
A. clock
The force between two magnetic poles is ___________ their pole strengths A. directly proportional to B. the sum of C. inversely proportional to D. the product of
A. directly proportional to
The charging of a capacitor through a resistance obeys A. exponential law B. linear law C. logarithmic law D. square law
A. exponential law
The current going into a point in a dc circuit always equal to the current: A. flowing out of the point B. delivered by the power supply C. through any one of the resistances D. at any other point
A. flowing out of the point
For a certain magnetic material, the ___ the area inside the hysteresis loop, the __ the hysteresis losses. A. greater, larger B. smaller, larger C. greater, smaller D. smaller, smaller
A. greater, larger
What is the value of current below which the SCR switches from the conduction state to the forward blocking region under stated conditions? A. holding current B. forward current C. reverse current D. trigger current
A. holding current
An RLC series circuit is underdamped. To make it overdamped, the value of R has to be ________. A. increased B. decreased C. increased to infinity D. reduced to zero
A. increased
When negative current feedback is applied to an amplifier, its output impedance A. increases B. remains unchanged C. decreases D. becomes zero
A. increases
An SCR differs from the 4-layer diode because A. it has a gate terminal B. it is not a thyristor C. it does not have four layers D. it cannot be turned on and off
A. it has a gate terminal
The value of negative feedback fraction is always ___________. A. less than 1 B. more than 1 C. equal to 1 D. none of the above
A. less than 1
The only way to stop an SCR that is conducting is by A. low-current drop out B. reverse-bias triggering C. a positive trigger D. breakover
A. low-current drop out
The electrons in the largest orbit travel _____________ than the electrons in the smaller orbits. A. more slowly B. faster C. in the same velocity D. a little bit slower
A. more slowly
When the number of free electrons is increased in doped semiconductor , it becomes a/an _____________ semiconductor. A. n type B. pn type C. p type D. np type
A. n type
Capacitance is defined as the property of a circuit that A. opposes a change in voltage B. aids a change in voltage C. opposes a change in current D. aids a change in current
A. opposes a change in voltage
The output signal of a CE amplifier is always A. out of phase with the input signal B. equal to the input signal C. in phase with the input signal D. larger than the input signal
A. out of phase with the input signal
The rms value is the same as the peak value of A. perfect square waves B. sawtooth waves C. perfect triangle waves D. perfect sine waves
A. perfect square waves
Conventional flow assumes charges flow from A. positive to negative B. positive to positive C. negative to positive D. negative to negative
A. positive to negative
The ratio of W/VA in an ac circuit means A. power factor B. quality factor C. reactive factor D. load factor
A. power factor
The time interval that a waveform is high (or low) is the ___________ of the signal. A. pulse width B. pulse position C. pulse length D. duty cycle
A. pulse width
Wave A = 100sinwt and wave B = 100coswt. Then A. rms values of the two waves are equal B. rms values of A is more than that of B C. rms values of A is less than that of B D. rms values of the two waves may or may not be equal
A. rms values of the two waves are equal
Drain current in the constant-current region increases when A. the gate-to-to-source bias voltage decreases B. the gate-to-source bias voltage increases C. the drain-to-source voltage increases D. the drain-to-source voltage decreases
A. the gate-to-to-source bias voltage decreases
A p-channel MOSFET operating in the enhancement mode is characterized by Vt=-3V and Idq= -8 mA when Vgsq= -4.5V. Find Vgsq if Idq= -16mA. A. -0.80V B. -0.88V C. -0.94V D. -0.78V
B. -0.88V
If the ratio of Xc/R is -1, the phase angle is: A. 0deg B. -45deg C. -90deg D. 45deg
B. -45deg
The lowest frequency passed by a low-pass filter is A. 1 Hz B. 0 Hz C. 10 Hz D. Dependent on critical frequency
B. 0 Hz
The output and input voltages of an emitter follower have a phase difference of ____________. A. 180 degrees B. 0 degrees C. 90 degrees D. 270 degrees
B. 0 degrees
A certain passive network has equivalent impedance Z=3+4i ohms and an applied voltage v=42.5cos(1000t+30deg)V. Determine the power factor. A. 0.6 lagging B. 0.6 leading C. 0.7 lagging D. 0.7 leading
B. 0.6 leading
If a circuit has an input admittance of 40 + j20 and the applied voltage of 180 V, what is the power factor? A. 0.922 leading B. 0.894 leading C. 0.894 lagging D. 0.922 lagging
B. 0.894 leading
In Boolean algrebra, a high signal added to another low signal is A. 10 B. 1 C. 11 D. 0
B. 1
The gain of an amplifier without feedback is 50 whereas with negative voltage feedback, it falls to 25. If due to ageing, the amplifier gain falls to 40, find the percentage reduction in stage gain with negative feedback. A. 20% B. 11.2% C. 14.5% D. 9.4%
B. 11.2%
The collector voltage of a Class B push pull amplifier with Vcc=40 Volts swings down to a minimum of 4 volts. The total power dissipation in both the transistors is 36 watts. Compute the total dc power input. A. 123.32 W B. 122.85 W C. 155.65 W D. 199.56 W
B. 122.85 W
A logic circuit has four inputs A, B, C, and D. How many possible input combination are there? A. 4 B. 16 C. 8 D. 32
B. 16
What is the half-power bandwidth of a parallel resonant circuit which has a resonant frequency of 3.6 MHz and Q of 218? A. 1.65 kHz B. 16.5 kHz C. 16.5 MHz D. 165 kHz
B. 16.5 kHz
How much energy in joules is required to move a charge of 6 C through a difference in potential of 3 V? A. 17 J B. 18 J C. 19 J D. 20 J
B. 18 J
A series RC circuit is to have an initial charging current of 4mA and a time constant of 3.6 sec when connected to a 120V DC source. Calculate the values of "R" and "C" respectively. A. 20kohms, 100uF B. 30kohms, 120uF C. 20kohms, 60uF D. 30kohms, 20uF
B. 30kohms, 120uF
The gain of a transistor in a common-emitter circuit is 100 at a frequency of 1000Hz. The gain is 70.7 at 335kHz. The gain drops to 1 to 210Mhz. The alpha cut-off is : A. 1kHz B. 335kHz C. 210kHz D. 70.7kHz
B. 335kHz
A device has a voltage gain of 23dB. The input voltage is 3.3V. The output voltage is: A. 76V B. 47V C. 660V D. 56V
B. 47V
If a wire coil has 10 turns and carries 500 mA of current, what is the magnetic force in ampere-turn? A. 5000 B. 5 C. 50 D. 0.02
B. 5
A certain bipolar transistor PA is 66 percent efficient. The output power is 33W. The dc collector power input is: A. 22W B. 50W C. 100W D. 2.2kw
B. 50W
A wattmeter shows 57 watts of VA power in a circuit. The resistance is known to be 50 ohms, and the true power is known to be 40 watts. What is the absolute-value impedance? A. 50 ohms B. 71 ohms C. 57 ohms D. 65 ohms
B. 71 ohms
A electric power line carries a current of 1400A in a location where the earth's magnetic field is 5.0x10^-5T. The line makes an angle of 75deg with respect to the field. Determine the magnitude of the magnetic force pm a 120-m length of line. A. 8.50N B. 8.11N C. 7.82N D. 8.66N
B. 8.11N
How can a class C amplifier be made linear? A. By reducing the bias B. A class C amplifier cannot be made linear C. By increasing the drive D. By using two transistor in push-pull
B. A class C amplifier cannot be made linear
The bipolar transistor or JFET in the multi-vibrator is A. Class B B. A common-emitter or common-source arrangement C. Class C D. A common-collector or common-drain arrangement
B. A common-emitter or common-source arrangement
What type of linear regulator is used in applications requiring efficient utilization of the primary power source? A. A constant current source B. A series regulator C. A shunt regulator D. A shunt current source
B. A series regulator
Transformer coupling is an example of A. Direct coupling B. AC coupling C. DC coupling D. Impedance coupling
B. AC coupling
A charge atom is known as: A. A molecule B. An ion C. An isotope D. An electron
B. An ion
What order of Q is required by a tank-circuit sufficient to reduce harmonics to an acceptable level? A. Approximately 120 B. Approximately 12 C. Approximately 1200 D. Approximately 1.2
B. Approximately 12
What factors determine the capacitance of a capacitor? A. Area of the plates, voltage on the plates and distance between the plates B. Area of the plates, distance between the plates and the dielectric constant of the material between the plates C. Area of the plates, voltage on the plates and the dielectric constant of the material between the plates D. Area of the plates, amount of charge on the plates and the dielectric constant of the material between the plates
B. Area of the plates, distance between the plates and the dielectric constant of the material between the plates
What are considered as the main types of battery? A. Lithium cell and alkaline B. Carbon-zinc dry cell and lead-sulfuric wet cell C. Leclanche cell and carbon-zinc D. Voltaic cell and lithium cell
B. Carbon-zinc dry cell and lead-sulfuric wet cell
It is a two-port transistor arrangement in which the base shares a common point with the input and output terminals. A. Common-Emitter B. Common-Base C. Common-Collector D. Common-Ground
B. Common-Base
A moving system force in analog instruments which ensures that the deflection of the pointer for a given value of measured quantity always has the same value. A. Damping force B. Controlling force C. NRZ force D. Deflecting force
B. Controlling force
The meter movement in an illumination meter measures A. Voltage B. Current C. Power D. Energy
B. Current
The meter movement in an illumination meter measures: A. Voltage B. Current C. Power D. Energy
B. Current
Which is the best type of meter movement? A. Iron-wave B. D' Arsonval C. Dynamometer D. Moving iron
B. D' Arsonval
One of the effects of negative feedback in amplifier is to A. Increase the noise B. Decrease the harmonic distortion C. Decrease the bandwidth D. Increase the harmonic distortion
B. Decrease the harmonic distortion
In a phototransistor, the base current is A. Set by a bias voltage B. Directly proportional to the light C. Inversely proportional to the light
B. Directly proportional to the light
Which of the following is not a primary cell? A. Carbon-zinc B. Edison cell C. Zinc chloride D. Mercuric oxide
B. Edison cell
A positive electric pole A. Has a deficiency of electrons B. Has a fewer electrons than a negative pole C. Has an excess of electrons D. Has more electrons than the negative pole
B. Has a fewer electrons than a negative pole
If the waves has the same frequency and the same phase, the composite wave: A. Has a magnitude equal to the difference between the two originals B. Has a magnitude equal to the sum of the two originals C. Is a complex, with the same frequency of the original D. Is zero
B. Has a magnitude equal to the sum of the two originals
A simple pi network with inductors on each leg and a capacitor in the center is a: A. Bandpass filter B. High pass filter C. Low pass filter D. Notch filter
B. High pass filter
What are the majority current carriers in the PNP transistor and the NPN transistor? A. Holes; holes B. Holes; electrons C. Elements; holes D. Electrons; electrons
B. Holes; electrons
A CMOS integrated circuit: A. Can only work at low frequencies B. Is susceptible to damage to static C. Requires considerable power to function D. Need very high voltage
B. Is susceptible to damage to static
What is the major advantage of a Pierce oscillator? A. It is easy to neutralize B. It doesn't require an LC tank circuit C. It can be tuned over a wide range D. It has a high output power
B. It doesn't require an LC tank circuit
What is the purpose of a multiplier resistor used with a voltmeter? A. A multiplier resistor is not used with a voltmeter B. It is used to increase the voltage indicating range of the voltmeter C. It is used to decrease the voltage indicating range of the voltmeter D. It is used to increase the current indicating range of an ammeter not a voltmeter
B. It is used to increase the voltage indicating range of the voltmeter
At series resonance, the voltage across L or C is A. Equal to the applied voltage B. Less than the applied voltage C. Much more than the applied voltage D. Equal to the voltage across R
B. Less than the applied voltage
If X is low, what is the state of X AND Y? A. Not enough information to tell B. Low C. High D. This logic makes no sense
B. Low
An IC constructed entirely on a single silicon chip A. Thin-film B. Monolithic C. Thick-film D. Hybrid
B. Monolithic
Which of the following is a way of decreasing mutual inductance? A. Moving the coils closer B. Moving the coils apart C. Decreasing the number of turns of either coil D. Increasing the number of turns of either coil
B. Moving the coils apart
An ideal amplifier has A. Noise figure of less than 1 dB B. Noise factor of unity C. Output S/N more than input S/N D. Noise figure of more than 0 dB
B. Noise factor of unity
Which of the following types of capacitors are referred to as self-healing? A. Ceramic B. Oil C. Paper D. Mica
B. Oil
Which of the following does NOT have rail-to-rail output? A. Static CMOS B. PPL C. Pseudo-nMos D. CMOSTG
B. PPL
What process takes place within the semiconductor to cause hole flow? A. The breaking of covalent bonds B. The combining of valence bands C. The flexing of the material D. The splitting of atoms
B. The combining of valence bands
In a series-connected string of holiday ornamental bulbs, if one gets shorted out, which of these is most likely? A. All the other bulb will go out B. The current is the string will go up C. The current is the string will go down D. The current is the string will go stay the same
B. The current is the string will go up
An advantage of high frequency operation of a DC-DC converter is: A. A small filter capacitor may be used B. The output does not need to be filtered C. Less RFI is generated D. Fewer components are required
B. The output does not need to be filtered
What determines whether a substance is an insulator, semi-conductor, or conductor? A. The separation between the valence and forbidden bands B. The separation between the conduction and valence bands C. The separation between the conduction and forbidden bands D. The separation between the forbidden band and the energy gap
B. The separation between the conduction and valence bands
The transistor terminal voltage is consider positive if A. The terminal is more negative than the common terminal B. The terminal is more positive than the common terminal C. The terminal is the output terminal D. The terminal is connected to P-type material
B. The terminal is more positive than the common terminal
A film of material with a thickness that is at least 10 times greater than the mean free path of an electron in that material. A. Thin film B. Thick film C. Vacuum evaporation film D. Hybrid microcircuit
B. Thick film
What is equalizing charge? A. Used in emergency only B. Used periodically as part of a maintenance routine C. Used to keep a battery at full charge while the battery is idle D. Used after electrolyte is added to a dry shipped battery
B. Used periodically as part of a maintenance routine
What type of dielectric is least sensitive to power dielectric-hysteresis losses? A. Pure water B. Vacuum C. Air D. Mica
B. Vacuum
In an N-channel JFET, pinchoff occurs when the gate bias is A. Slight positive B. Very negative C. Zero D. Slight negative
B. Very negative
In nMOS transistor, which operation is for saturation mode? A. Vgs = 0 and Vgd is high B. Vgs > Vt, Vgs < Vgc and Vds > Vgs - Vt C. Vgs > Vt, Vgd = Vgs, and Vds = 0 D. Vgs > Vt, Vgs>Vgc>Vt, and 0<Vds<Vgs-Vt
B. Vgs > Vt, Vgs < Vgc and Vds > Vgs - Vt
In nMOS transistor, which operation is for saturation mode? A. Vgs>Vo, Vgs>Vgd>Vth, and 0<Vds<Vgs-Vth B. Vgs>Vth, Vgs<Vgd, and Vds>Vgs-Vth C. Vgs>Vth, Vgd=Vgs and Vds=0 D. Vgs=0 and Vgd is high
B. Vgs>Vth, Vgs<Vgd, and Vds>Vgs-Vth
What is a method of converting chemical energy into electric energy by dissolving two different conducting materials in an electrolyte? A. Battery B. Voltaic cell C. Cell D. Charging
B. Voltaic cell
The UJT may be used as A. an amplifier B. a sawtooth generator C. a rectifier D. a multivibrator
B. a sawtooth generator
Which of the following with not cause a major error in an ohmmeter? A. a small voltage between points under test B. a small change in resistance to be measured C. a slight error in the range switch selection D. a slight change in switchable internal resistance
B. a small change in resistance to be measured
A transformer has a secondary-to-primary turn ratio is 0.6. This transformer is: A. a step-up unit B. a step-down unit C. neither step-up and step-down circuit D. a reversible unit
B. a step-down unit
A class A circuit would not work well as: A. a stereo hi-fi amplifier B. a television transmitter PA C. a low-level microphone preamplifier D. the first stage in the radio receiver
B. a television transmitter PA
For a UJT, the intrinsic standoff ratio is A. equal to 1 B. always less than 1 C. always greater than 1 D. usually around 1k or so
B. always less than 1
An emitter follower is equivalent to A. common emitter amplifier B. common collector amplifier C. common base amplifier D. hybrid connection
B. common collector amplifier
Emitter follower is a _____________ circuit. A. voltage feedback B. current feedback C. both voltage and current feedback D. none of the above
B. current feedback
The pointer of an indicating instrument is in the final deflected position, the ___________ is zero. A. deflecting torque B. damping torque C. controlling torque D. frictional
B. damping torque
The input impedance of an amplifier ____________ when negative current feedback is applied. A. remains unchanged B. decreases C. increases D. becomes zero
B. decreases
An XOR gate produces an output only when its two inputs are A. High B. different C. low D. same
B. different
The major advantage of silicon-on-insulator are the following except: A. low diffusion capacitance B. higher diffusion capacitance C. lower dynamic power consumption D. nominals threshold voltage must be very high
B. higher diffusion capacitance
In a p-channel FET, the charge carriers are __________. A. electrons B. holes C. both holes and electrons D. ions
B. holes
The only way to stop an SCR that is conducting is by A. breakover B. low-current drop out C. reverse bias triggering a positive trigger D. a positive trigger
B. low-current drop out
When the movable plates of a gang capacitor completely overlap the fixed plates, the capacitance of the capacitor is A. halfway between maximum and minimum B. maximum C. minimum D. zero
B. maximum
For the same rating, the size of low-speed alternator is ____________ that of high-speed alternator. A. about the same as B. more than C. less than D. twice
B. more than
When a differential amplifier is operated single-ended A. the output is grounded B. one input is grounded and a signal is applied to the other C. both inputs are connected together D. the output is not inverted
B. one input is grounded and a signal is applied to the other
The capacitors are considered _______________ in the dc equivalent circuit of a transistor amplifier. A. short B. open C. partially short D. partially open
B. open
For enhancement mode MOSFET, Vgs is always A. negative B. positive C. zero D. dependent on the application of the device
B. positive
When current and voltage are in-phase in an ac circuit, the ___________ is equal to zero A. resistance B. reactance C. inductance D. capacitance
B. reactance
The input signal to a transistor amplifier results in saturation during part of the cycle. This produces: A. the greatest possible amplification B. reduced efficiency C. avalanche effect D. nonlinear output impedance
B. reduced efficiency
What maximum voltage can be applied across the capacitor for very short period of time? A. working voltage B. surge voltage C. stray voltage D. peak voltage
B. surge voltage
In a CE amplifier, A. both ac and dc load lines have the same slope B. the ac load line has more slope than dc load line C. the ac load line has less slope than dc load line D. the two load lines may have slope more than the other
B. the ac load line has more slope than dc load line
Photoconductive effect means A. the decreased conductivity of an illuminated semiconductor junction B. the increased conductivity of an illuminated semiconductor junction C. the conversion of photonic energy to electromagnetic energy D. the conversion of an electromagnetic energy to photonic energy
B. the increased conductivity of an illuminated semiconductor junction
In negative-edge triggering, the change of state occurs when: A. the pulse level is high B. the pulse level is going high to low C. the pulse level is going from low to high D. the pulse level is low
B. the pulse level is going high to low
Delta to wye or wye to delta transformation technique is applied to a _____________ network. A. one-terminal B. three-terminal C. two-terminal D. complex
B. three-terminal
The three terminals of a triac are A. drain, source, gate B. two main terminals and a gate terminal C. cathode, anode, gate D. anode, source, gate
B. two main terminals and a gate terminal
The term "semiconductor" arises from A. resistor-like properties of metal oxides B. variable conductive properties of some materials C. the fact that there's nothing better to call silicon D. insulator properties of silicone and GaAs
B. variable conductive properties of some materials
In an N-channel JFET, pinchoff occurs when the gate bias is A. slightly negative B. very negative C. slightly positive D. zero
B. very negative
In an ac circuit with XL and R in series, the A. voltages across R and XL are in phase B. voltage across R lags the voltage across XL by 90 degrees C. voltages across R and XL are 180 degrees out-of-phase D. voltage across R leads the voltage across XL by 90 degrees
B. voltage across R lags the voltage across XL by 90 degrees
In an ac circuit with XL and R in series, the A. voltages across R and XL are in phase B. voltage across R lags the voltage across XL by 90 degrees C. voltages across R and XL are 180 degrees out-of-phase D. voltage across R leads the voltage across XL by 90 degrees
B. voltage across R lags the voltage across XL by 90 degrees
What is the voltage drop across the resistor in an RC charging circuit when the charge on the capacitor is equal to the battery voltage? A. 0.10 volt B. zero C. 1.0 volt D. 10 volts
B. zero
The permeability of permalloy is A. slightly less than permeability of air B. slightly greater than permeability of air C. very much larger than permeability of air D. equal to the permeability of air
C very much larger than permeability of air
From the op-amp circuit, calculate Vo. A. -12 V B. -8 V C. -10 V D. -14 V
C. -10 V
A relay coil having a pick up current of 10 mA is connected in series with an inductance. The total resistance is 100 mH. If 20V DC source is applied at time t=0, at which time will the relay pick up? A. 6.93 x 10^-5 sec B. 1 x 10^-3 sec C. 1 x 10^3 sec D. 5.13 x 10^-5 sec
C. 1 x 10^3 sec
For an P-channel enhancement type MOSFET, determine the drain current if K=0.278 x 10^-3 A/V^2, Vgs=4 V, Vt=2 V, Voltage equivalent at 27 C = 26 mV. A. 10 mA B. 0.751 mA C. 1.11 mA D. 46.98 mA
C. 1.11 mA
A phase difference of 180 degrees in the circular model: A. 1/4 revolution B. A full revolution C. 1/2 revolution D. Two full revolutions
C. 1/2 revolution
An amplifier exhibits distortion in the form of voltage fluctuations of ~ 10%. These fluctuations are to be restricted to ~ 1% by incorporating negative feedback in the amplifier circuit. If ultimate gain is desired to be 120, what should be the open loop gain of the amplifier? A. 2400 B. 600 C. 1200 D. 120
C. 1200
A 100-kVA transformer is at 80 percent of rated load at power factor 0.85 lagging. How many kVA in additional load at 0.60 lagging power factor will bring the transformer to full rated load? A. 21.8 kVA B. 22.2 kVA C. 21.2 kVA D. 22.4 kVA
C. 21.2 kVA
Find the counter emf of a motor when the terminal voltage is 240V and the armature current is 50A. The armature resistance is 0.08ohms. The field current is negligible. A. 244V B. 240V C. 236V D. 232V
C. 236V
The transistor of following figure in Si diode with a base current of 40 uA and Icbo=0, if Vgs=6V, Re=2kohms and B=90, Ibq=20uA then Rb= A. 200 kohms B. 150 kohms C. 265 kohms D. 100 kohms
C. 265 kohms
What current is required in the windings of a long solenoid that has 1000 turns uniformly distributed over a length of 0.40m in order to produce a magnetic field of magnitude 1x10^-4 T at the center of the solenoid A. 29.8mA B. 31.3mA C. 31.8mA D. 32.3mA
C. 31.8mA
A silicon diode has a maximum allowable junction temperature of 150 C. Find the maximum allowable power dissipation at 25 C ambient temperature if the diodes thermal resistance is 0.4 C/mW. A. 238 mW B. 566 mW C. 313 mW D. 117 mW
C. 313 mW
An ac series circuit is composed of a resistance of 20 ohms, inductive reactance of 40 ohms, and a capacitive reactance of 15 ohms. If a current of 1 ampere is flowing, what is the applied voltage? A. 320 V B. 220 V C. 32 V D. 22 V
C. 32 V
Three resistance of 15 ohms each are connected in delta. The resistance of equivalent star will have a value of A. 15 ohms B. 5/3 ohms C. 5 ohms D. 45 ohms
C. 5 ohms
Two capacitors of capacitance 9 uF and 18 uF in series with each other have a total capacitance of A. 27 uF B. 162 uF C. 6 uF D. 180 uF
C. 6 uF
A silicon power transistor is operated with a sink (0sa= 1,.5degC/W). The transistor, rated at 150W(25degC) has 0jc=0.5degC/W, and the mounting insulation has 0cs=0.6degC/W. What maximum power can be dissipated if the ambient temperature is 40degC and tjmax=200degC? A. 63.5W B. 57.5W C. 61.5W D. 58.2W
C. 61.5W
A cell of 1.5V supplies 100 mA for seven hours and twenty minutes, and then it is replaced. It has supplied: A. 7.33 Ah B. 7.33 Wh C. 733 mAh D. 733 mWh
C. 733 mAh
Find Q of a circuit when the resonant frequency is 14.128 MHz, the inductance is 2.7 uH and the resistance is 18,000 ohms are in parallel A. 751 B. 7.51 C. 75.1 D. 71.5
C. 75.1
Convert 111101.01101 to octal A. 75.23 B. 76.32 C. 75.32 D. 75.22
C. 75.32
Convert 111101.01101 to octal A. 78.32 B. 75.23 C. 75.32 D. 75.22
C. 75.32
In the circuit below, the Zener diode has a breakdown voltage Vzt=8.0V and a measurement has shown that Vz=8.6V when Iz=30mA. What is the value of Vout when Rl becomes infinitely large? A. 0V B. 8.2V C. 8.8V D. 8.4V
C. 8.8V
The impedance of R-C series circuit is 100ohms. If circuit current leads the applied voltage by 60 degrees, the capacitive reactance is ______________. A. 50 ohms B. 70.7 ohms C. 86.6 ohms D. 200 ohms
C. 86.6 ohms
Suppose that an ion source in a mass spectrometer produces doubly ionized gold ions each with a mass of 3.27x10^-25 kg. The ions are accelerated from rest rhrough a potential difference of 1.00kV. Then, a 0.500-T magnetic field causes the ions to follow a circular path. Determine the radius of the path. A. 8.0 cm B. 8.5 cm C. 9.0 cm D. 9.5 cm
C. 9.0 cm
What is a CMOS IC? A. A chip with only bipolar transistors B. A chip with n-channel transistors C. A chip with p-channel (pmos) and n-channel (nmos) transistors D. A chip with p-channel transistors
C. A chip with p-channel (pmos) and n-channel (nmos) transistors
Which type of IC is used to determine whether voltage levels are the same or not? A. An op-amp B. A timer C. A comparator D. A multiplexer demultiplexer
C. A comparator
What is the principal characteristic of a zener diode? A. A constant current under conditions of varying voltage B. A high forward current rating C. A constant voltage under conditions of varying current D. A very high PIV
C. A constant voltage under conditions of varying current
What is the principal characteristic of a tunnel diode? A. A high forward resistance B. A very high PIV (peak inverse voltage) C. A negative resistance region D. A high forward current rating
C. A negative resistance region
An advantage of rheostat over a potentiometer is that A. A rheostat is more precise B. A rheostat can handle higher frequencies C. A rheostat can handle more current D. A rheostat work better with dc
C. A rheostat can handle more current
Which of the following will not cause a major error in an ohmmeter? A. A small voltage between points under test B. A slight change in switchable internal resistance C. A small change in the resistance to be measured D. A slight error in the range switch selection
C. A small change in the resistance to be measured
A material with a high dielectric constant: A. Acts to decrease capacitance per unit volume B. Has no net effect on capacitance C. Acts to increase capacitance per unit volume D. Cause a capacitance to become polarize
C. Acts to increase capacitance per unit volume
Which of the following dielectric materials makes the lowest-capacitance capacitor? A. Paper B. Mica C. Air D. Electrolyte
C. Air
What is the common name for manganese dioxide-alkaline-zinc cell? A. Manganese-dioxide cell B. Long-life cell C. Alkaline cell D. Moz cell
C. Alkaline cell
Lines of magnetic flux are said to originate A. In charge carriers B. Where the lines converge to a point C. At a north magnetic pole D. In atoms of ferromagnetic materials
C. At a north magnetic pole
The number of protons in the nucleus of an element is the: A. Electron number B. Valence number C. Atomic number D. Proton number
C. Atomic number
Capacitance and inductance in a circuit are similar in which of the following ways? A. Both oppose current B. Both aid voltage C. Both cause the storage of energy D. Both prevent the storage of energy
C. Both cause the storage of energy
How can electrical currents be induced with a coil and a magnet? A. By placing the coil parallel to the magnetic field B. By placing the coil at right angles with the magnetic field C. By moving either the magnet or the coil D. By keeping the coil and the magnet perfectly stationary
C. By moving either the magnet or the coil
In a class A amplifier, condition extends over 360 degrees because Q-point is A. Located on load line B. Located near saturation point C. Centered on load line D. Located at or near cut-off point
C. Centered on load line
What class of amplifier is distinguished by the flow of current in the output essentially in 180 degree pulses? A. Class A B. Class C C. Class B D. Class D
C. Class B
The quiescent collector current is the same as the A. AC collector current B. Total collector current C. DC collector current D. Voltage-divider current
C. DC collector current
To amplify dc signals, multistage amplifier uses what coupling? A. RC B. Transformer C. Direct D. Resistor
C. Direct
In a phototransistor, base current is A. Set by a bias voltage B. Inversely proportional to the light C. Directly proportional to the light D. Not a factor
C. Directly proportional to the light
When used for an ac current control, during which alternation of the ac cycle does the TRIAC control current flow? A. During positive alternations B. During negative alternations C. During both alternations D. Fixed current
C. During both alternations
All voltmeters except one of the following are operated by the passage of current. A. Moving-iron B. Dynamometer C. Electrostatic D. Permanent-magnet moving coil
C. Electrostatic
A diac has how many semiconductor layers? A. Three B. Two C. Four D. Five
C. Four
A diac has how many semiconductor layers? A. Three B. Two C. Four D. Five
C. Four
Which of the following can vary with AC, but not DC? A. Power B. Voltage C. Frequency D. Magnitude
C. Frequency
To flush a hydrometer, which of the following liquids should be used? A. Sulfuric acid B. Salt water C. Fresh water D. A solution of baking soda and water
C. Fresh water
If an electron moves from right to left across this page and suddenly is subjected to a magnetic field directed into the page, what is the direction of the magnetic force on the electron? A. into the page B. Out of the page C. From the bottom to the top of the page D. From the top to the bottom of the page
C. From the bottom to the top of the page
An autotransformer: A. Work automatically B. Has a center-tapped secondary C. Has one tapped winding D. Is useful only for impedance matching
C. Has one tapped winding
A semiconductor device with four alternating layers (P-N-P-N) taht are controlled by a metal-oxide-semiconductor (MOS) gate structure without regenerative action. A. SCR B. thyristor C. IGBT D. triac
C. IGBT
An oscillator might fail to start for any of the following reasons except: A. Low power supply voltage B. Low stage gain C. In-phase feedback D. Very low output impedance
C. In-phase feedback
What is automatically compensated in a wattmeter? A. Line resistance B. Overdamping C. Inductive reactance D. Power factor
C. Inductive reactance
What do you call a semiconductor in its purest form? A. Pure semiconductor B. Doped semiconductor C. Intrinsic semiconductor D. Extrinsic semiconductor
C. Intrinsic semiconductor
The maximum voltage output from a voltage divider A. Is a fraction of the power supply B. Depends on the total resistance C. Is equal to the supply voltage D. Depends on the ratio of the resistances
C. Is equal to the supply voltage
A ammeter shunt is useful because A. It prevents overheating of the meter B. It makes a meter more physically rugged C. It allows for measurements of a wide range of current D. It increases meter sensitivity
C. It allows for measurements of a wide range of current
According to Lenz's Law, the induced emf produced by a change in current in an inductive circuit tends to have what effect on the current? A. It aids a rise in current and opposes fall in current B. It aids a fall in current and opposes a rise in current C. It opposes either a rise or a fall in current D. It aids either a rise or fall in current
C. It opposes either a rise or a fall in current
To increase the brightness of a desk lamp a student replaces a 50 W light bulb with a 100 W light bulb. Compared to the 60 W light bulb, the 100 W light bulb has? A. More resistance and draws more current B. More resistance and draws less current C. Less resistance and draws more current D. Less resistance and draws less current
C. Less resistance and draws more current
Of the following types of cells, which one is a primary cell? A. Nickel cadmium B. Silver zinc C. Lithium organic D. IDK
C. Lithium organic
A logic gate which produces an output which is false only if all its inputs are true A. NOR B. OR C. NAND D. AND
C. NAND
A logic circuit has an output 0 when the input is 1 and vice versa. A. NOR gate B. OR gate C. NOT gate D. XOR gate
C. NOT gate
Inductive susceptance is A. Equal to capacitive reactance B. The measure of the opposition a coil offers to ac C. Negative imaginary D. The reciprocal of inductance
C. Negative imaginary
The electric flux through a surface of fixed area is maximum when the surface is A. Parallel to the electric field B. Antiparallel to the electric field C. Perpendicular to the electric field D. At an angle of 45 degrees to the electric field
C. Perpendicular to the electric field
What diode modeling circuit considers the threshold voltage, average resistance and switch as the diode's equivalent circuit? A. Ideal model B. Simplified model C. Piecewise linear model D. Real model
C. Piecewise linear model
DC shunt motors are used in those applications where what is required? A. High starting torque B. High no-load speed C. Practically constant speed D. Variable speed
C. Practically constant speed
The smallest possible unit cell A. Face Center Cubic B. Simple Cubic Cell C. Primitive Cell D. Body Center Cubic Cell
C. Primitive Cell
If all the delta connected resistor are identical, what is the equivalent value of the resistor in WYE connection? A. R B. R/2 C. R/3 D. R/4
C. R/3
It can also be used to locate the source of a field, and to measure the performance of radio frequency shielding. A. oscilloscope B. logic analyzer C. RF meter D. spectrum analyzer
C. RF meter
The primary cause on linear distortion in amplifier is A. Change of gain with frequency B. Unequal phase shift in component frequencies C. Reactances associated with the circuit and active amplifying element D. Inherent limitations of the active device
C. Reactances associated with the circuit and active amplifying element
If the angle of incident of a light ray is greater than the critical angle, the light will be A. Absorbed B. Amplified C. Reflection D. Refraction
C. Reflection
What drives high-speed alternators? A. Diesel engines B. Hydraulic turbines C. Steam turbines D. Diesel engines
C. Steam turbines
The advantage of J-K over R-S flip-flop is that A. The J-K flip-flop is faster B. The J-K can attain more states C. The J-K always has predictable output D. An R-S flip-flop is superior to a J-K
C. The J-K always has predictable output
After the junction recombination process has reached equilibrium, what is the area that surrounds the junction called? A. The anode B. The free ion space C. The depletion region D. The electrostatic field
C. The depletion region
The ac load line differs from the dc load line because A. The effective dc collector resistance is less than the dc collector resistance B. The effective ac collector resistance is less than the ac collector resistance C. The effective ac collector resistance is less than the dc collector resistance D. The effective ac collector resistance is greater than the dc collector resistance
C. The effective ac collector resistance is less than the dc collector resistance
Which is the following units can represent magnetic flux density? A. The volt-turn B. The ampere-turn C. The gauss D. The gauss-turn
C. The gauss
The signal handling capacity of an amplifier is high if A. The operating point is selected near the cut-off region B. The operating point is selected near the saturation region C. The operating point is selected near the biasing region D. The operating point is selected near the operating point
C. The operating point is selected near the biasing region
The damping factor of an active filter determines A. The voltage gain B. The critical frequency C. The response characteristic D. The roll-off rat
C. The response characteristic
Which of the following is the main function of a dc motor? A. To generate power B. To change mechanical energy to electrical energy C. To change electrical energy to mechanical energy D. To change chemical energy to mechanical energy
C. To change electrical energy to mechanical energy
What is the purpose of capacitors in a transistor amplifier? A. To protect the transistor B. To cool the transistor C. To couple or bypass ac component D. To provide biasing
C. To couple or bypass ac component
The state of JK latch when both signals are " 1 ". A. No change B. Reset C. Toggle D. Set
C. Toggle
A ___________ is like two parallel SCRs having a common gate and connected opposite directions. A. UJTs B. PUTs C. Triacs D. Diacs
C. Triacs
The PUT is A. Much like the UJT B. Not a four-layer device C. Trigger on and off by the gate-to-anode D. Not a thyristor
C. Trigger on and off by the gate-to-anode
Negative peak of emitter with class A the output voltage should be A. Clipped on positive voltage peak B. Clipped on negative voltage peak C. Unclipped D. Clipped on negative current peak
C. Unclipped
What is floating charge? A. Used in emergency only B. Used periodically as part of a maintenance routine C. Used to keep a battery at full charge while the battery is idle D. Used after electrolyte is added to a dry shipped battery
C. Used to keep a battery at full charge while the battery is idle
Suppose a certain current in the galvanometer causes the needle to deflect 20 degrees, and the current is doubled. The needle deflection: A. Will decrease B. Will stay the same C. Will increase D. Will reverse direction
C. Will increase
The superposition theorem is used when the circuit contains ______________ A. a single voltage source B. passive elements only C. a number of voltage sources D. active elements only
C. a number of voltage sources
How can electrical currents be induced with a coil and a magnet? A. by placing the coil parallel to the magnetic field B. by placing the coil at right angles with the magnetic field C. by moving either the magnet or the coil D. by keeping the coil and the magnet perfectly stationary
C. by moving either the magnet or the coil
To prevent a DC return between source and load, it is necessary to use A. resistor between source and load B. inductor between source and load C. capacitor between source and load D. Either A or B
C. capacitor between source and load
If a transistor is operated in such a way that output current flows for 160 degrees of the input signal, then its is ______________ operation. A. class A B. class B C. class C D. class AB
C. class C
The distance between the capacitor plates increases two times, then its capacitance A. increases two times B. increases four times C. decreases two times D. decreases four times
C. decreases two times
A linear circuit is one whose parameters A. change with change in voltage B. change with change in current C. do not change with voltage and current D. change with change in voltage and current
C. do not change with voltage and current
The period of an ac wave is A. the same as the frequency B. not related to the frequency C. equal to 1 divided by the frequency D. equal to the amplitude divided by the frequency
C. equal to 1 divided by the frequency
For a full-wave rectifier, the output frequency A. equals one-half the input frequency B. equals the line frequency C. equals two times the input frequency D. is three times the line frequency
C. equals two times the input frequency
A multiplexer A. stores data in multiple bits B. multiplies four 4-bit words C. has multiple inputs and a single output D. has a single input and multiple outputs
C. has multiple inputs and a single output
The output voltage of a thermocouple A. remains constant with temperature B. decreases with applied voltage C. increases with temperature D. increases with applied voltage
C. increases with temperature
In a two stage CE amplifier circuit, the ac collector resistance of the first stage depends on A. load resistance B. input impedance of first stage C. input impedance of second stage D. All of the above
C. input impedance of second stage
The maximum voltage output from a voltage divider: A. is a fraction of the power supply B. depends on the total resistance C. is equal to the supply voltage D.depends on the ratio of the reistances
C. is equal to the supply voltage
An SCR differs from the 4-layer diode because A. it is not a thyristor B. it does not have four layers C. it has a gate terminal D. it cannot be turned on and off
C. it has a gate terminal
A Zener diode has the specifications Vz = 5.2 V and Pdmax = 260 mW. Assume Rz = 0. Find the maximum allowable current iz when the Zener diode is acting as a regulator A. iz = 30mA B. iz = 45mA C. iz = 50mA D. iz = 60mA
C. iz = 50mA
If X is low, what is the state of X AND Y? A. not enough information to tell B. high C. low D. this logic makes no sense
C. low
A transistor has two p-n junctions. The batteries should be connected such that A. both junctions are forward biased B. both junctions are reverse biased C. one junction is forward biased and the other is reverse biased D. either A or B
C. one junction is forward biased and the other is reverse biased
A silicon sample at room temperature has an intrinsic carrier concentration of a = 5 x 10^9 cm^-3. It is doped with Nd = 6.1 x 10^15 arsenic atoms/cm^3 and Na = 6 x 10^12 boron atoms/cm^3. The electron mobility is measured as us = 1600 cm^2/V-s and the hole mobility is ud = 480 cm^2/V-s. What is the hole concentration? A. p = 6 x 10^12 /cm^3 B. p = 2.5 x 10^17 /cm^3 C. p = 4.1 x 10^2 /cm^3 D. p = 6.1 x 10^15 /cm^3
C. p = 4.1 x 10^2 /cm^3
A normally operated SCR has an anode which is ___________ with respect to cathode A. negative B. at zero potential C. positive D. at infinite potential
C. positive
The number of protons in the nucleus of an element is the: A. electron number B. valence number C. proton number D. atomic number
C. proton number
To turn off the SCR, which of the following is done? A. reduce gate voltage to zero B. reverse bias the gate C. reduce anode voltage to zero D. deuce cathode voltage to zero
C. reduce anode voltage to zero
If a certain circuit has a current that is lagging the voltage by 45 degrees, then it displays A. pure inductive reactance B. resistance and capacitive reactance C. resistance and inductive reactance D. pure capacitive reactance
C. resistance and inductive reactance
If a certain circuit has a current that is lagging the voltage by 45deg, then it displays A. pure inductive reactance B. resistance and capacitive reactance C. resistance and inductive reactane D. pure capacitive reactance
C. resistance and inductive reactane
The magnetic flux through a wire loop in a magnetic field does not depend on the___. A. area of the loop B. magnitude of the field C. shape of the loop D. angle between the plane of the loop and the direction
C. shape of the loop
CE amplifier is characterized by A. a low voltage gain B. moderate power gain C. signal phase reversal D. very high output impedance
C. signal phase reversal
When the SCR is OFF, the current in the circuit is A. exactly zero B. large leakage current C. small leakage current D. thermal current
C. small leakage current
Which of these is not a required condition for a balanced system? A. Ia + Ib + Ic = 0 B. Van + Vbn + Vcn = 0 C. source voltages are 120 degrees out of phase with each other D. load impedances for the three phases are equal
C. source voltages are 120 degrees out of phase with each other
A MOSFET differs from a JFET mainly because A. of the power rating B. the MOSFET has two gates C. the JFET has a pn junction D. MOSFETs do not have a physical channel
C. the JFET has a pn junction
In a P-channel JFET: A. the drain is forward-biased B. the gate-source junction is forward biased C. the drain is negative relative to the source D. the gate must be at the dc ground
C. the drain is negative relative to the source
A Wheatstone bridge is balanced if A. the ratio of resistors on one side of the bridge is one while the ratio of resistors on the other side is infinity B. the ratio of resistors on one side of the bridge is greater than the ratio of resistors on the other side C. the ratio of resistors on one side of the bridge equals the ratio of resistors on the other side D. the bridge uses identical resistors
C. the ratio of resistors on one side of the bridge equals the ratio of resistors on the other side
An unimportant factor concerning the frequency at which a P-N junction will work effective is: A. the type of semiconductor materials B. the cross-sectional area of the junction C. the reverse current D. the capacitor with reverse bias
C. the reverse current
Calculate the gain of an inverting amplifier, If V = 4mV, calculate the output voltage A. 10, 40mV B. -10, 40mV C. 10, -40mV D. -10, -40mV
D. -10, -40mV
In the circuit of figure, the switch is closed at t = 0. At t = 0, what is the current through C? A. 4 A B. 3.1 A C. 2.5 A D. 0
D. 0
There are three resistor in parallel, with values of 22 ohms, 27 ohms and 33 ohms. A 12-V battery is connected across this combination. What is the current drawn by the 33 ohms resistor. A. 1.36 A B. 0.82 A C. 0.99 A D. 0.37 A
D. 0.37 A
A degree of phase represents: A. 6.28 cycles B. 1/6.28 cycles C. 57.3 cycles D. 1/360 cycles
D. 1/360 cycles
Calculate the total harmonic distortion for the amplitude components given D2=0.10, D3=0.04 and D4=0.02 A. 115 B. 10.75% C. 11.95% D. 10.95%
D. 10.95%
What is the minimum fan-out of TTL? A. 5 B. 20 C. 10 D. 2
D. 2
For either germanium or silicon diodes, the barrier potential decreases ____________ for each Celsius degree rise A. 1 mV B. 4 mV C. 3 mV D. 2 mV
D. 2 mV
The rate of gain reduction in operational amplifiers. A. 5 dB per decade (-5dB/decade) B. 6 dB per decade (-6dB/decade) C. 10 dB per decade (-10db/decade) D. 20 dB per decade (-20db/decade)
D. 20 dB per decade (-20db/decade)
A coil is represented by a series combination of L=50mH and R=15ohms. Calculate the quality factor at 10khz. A. 1047 B. 845 C. 326 D. 209
D. 209
Three resistors are connected in series to a 25V-battery. The resistances are 8ohms, R, and 16ohms. If the 16ohms resistor absorbs 5W, the ohmic value of R is closest to A. 40ohms B. 26ohms C. 3ohms D. 20ohms
D. 20ohms
Two inductors, each of 100 uH, are in series. The coefficient of coupling is 0.40. The net inductance, if the coil fields reinforce each other, is: A. 50 uH B. 200 uH C. 120 uH D. 280 uH
D. 280 uH
The resistor of 51 ohms, an inductor of 22 uH and a capacitance of 150 pF are in parallel. The frequency is 1 Mhz. What is the complex impedance, R + jX? A. 51 - j14.9 B. 46.2 - j14.9 C. 51 + j14.9 D. 46.2 + j14.9
D. 46.2 + j14.9
In a 208V three-phase circuit a balance delta load absorbs 2kW at a 0.8 leading power factor. Find the phase impedance. A. 48.1 <36.9ohms B. 49.9 <36.9ohms C. 50.5 <-36.9ohms D. 51.9 <-36.9ohms
D. 51.9 <-36.9ohms
A device that reverses magnetic field polarity to keep a dc motor rotating is: A. A solenoid B. A field coil C. An armature coil D. A commutator
D. A commutator
In a negative-logic circuit, what level is used to represent a logic 0? A. A low level B. A positive-transition level C. A negative-transition level D. A high level
D. A high level
A substance with high retentivity is best suited for making A. An ac electromagnet B. A dc electromagnet C. An electrostatic shield D. A permanent magnet
D. A permanent magnet
Which of the following factors should be considered when selecting a primary cell as a power source? A. Power requirement B. Type of electrolyte used C. Container material D. All of the above
D. All of the above
A fully charged lead-acid battery rated at 500 amp-hours could power a: A. 10 amp receiver for 50 hours B. 50 amp load for 10 hours C. 5 amp load for 100 hours D. All these
D. All these
What is the typical value of the innerbase resistance of UJTs? A. 20 kohms B. 4 kohms C. Between 4 to 4 kohms D. Between 4 to 10 kohms
D. Between 4 to 10 kohms
Which of the following is not a characteristic of UJT? A. Intrinsic standoff ratio B. Negative resistance C. Peak-point voltage D. Bilateral conduction
D. Bilateral conduction
Which of the following is the normal way to turn on an SCR? A. By breakover voltage B. By appropriate anode current C. By appropriate cathode current D. By appropriate gate current
D. By appropriate gate current
Lower cut-off frequency of an amplifier is primarily determined by the A. Internal capacitances of the active device used B. Stray capacitance between its wiring and ground C. AC Beta value of its active devices D. Capacitances of coupling and bypass capacitors
D. Capacitances of coupling and bypass capacitors
An SCS can be turned off by any of the following except A. Positive pulse on the anode gate B. Negative pulse on the cathode gate C. Reduce anode current above holding value D. Completely interrupt anode current
D. Completely interrupt anode current
What is the overall electrical charge of the N-material in a semiconductor? A. Zero B. Some negative value C. Some positive value D. Depending upon the balance of electrons it will be positive or negative
D. Depending upon the balance of electrons it will be positive or negative
The field-effect transistor (FET) A. Has three NP-junctions B. Incorporates a forward-biased junction C. Depends on the variation of a magnetic field for its operation D. Depends on the variation of the depletion-layer width reverse voltage for its operation
D. Depends on the variation of the depletion-layer width reverse voltage for its operation
Which of the following is a characteristic of the Zener diode? A. A PN-junction diode that operates in the reverse-bias breakdown region B. A PN-junction diode that uses the avalanche effect C. A PN-junction diode that uses the Zener effect D. Each of the above
D. Each of the above
In small inductance A. Energy is stored and release slowly B. The current flow is always large C. current flow is always small D. Energy is stored and release quickly
D. Energy is stored and release quickly
An oscillator might fail to start for any of the following reasons except: A. Low power supply voltage B. Low stage gain C. Very low output impedance D. In-phase feedback
D. In-phase feedback
Voltage leads current in which of the following types of circuits? A. Resistive B. Capacitive C. Both A and B above D. Inductive
D. Inductive
A coulomb A. Represents a current of one ampere B. Flows through a 100-watt light bulb C. Is one ampere per second D. Is an extremely large number of charge carriers
D. Is an extremely large number of charge carriers
To measure power supply voltage being by the circuit, a voltmeter: A. Is placed in series with the circuit that works from the supply B. Is placed between the negative pole of the supply and the circuit working from the supply C. Is placed between the positive pole of the supply and the circuit working from the supply D. Is placed in parallel with the circuit that works from the supply
D. Is placed in parallel with the circuit that works from the supply
The features of CASCADE amplifier are A. Reduced distortion B. Small input impedance C. Large output impedance D. Larger bandwidth
D. Larger bandwidth
The state of asynchronous enable SR latch when both signals are ' 1 ' and enable is ' 1 '. A. No change B. Reset C. Set D. Not allowed
D. Not allowed
A spectrum analyzer displays: A. Time as a function of frequency B. Frequency as function of time C. Signal strength as a function of time D. Signal strength as the function of frequency
D. Signal strength as the function of frequency
When a charge builds up without a flow of current, the charge is said to be: A. Inciting B. Electronic C. Molecular D. Static
D. Static
A device that are commonly used to test the frequency response of electronic filter circuits. A. Vector Network analyzer B. Spectrum analyzer C. Vectorscope D. Sweep generator
D. Sweep generator
The SCR is primarily used for what function A. Switch frequency on or off B. Generate current C. Control voltage D. Switching power on or off
D. Switching power on or off
The head of a nail is attracted to the north pole of a magnet and repelled by the magnet's south pole A. The nail is aluminum B. The nail is copper C. The nail is initially not magnetized D. The nail is magnetized
D. The nail is magnetized
What determines the direction of rotation of a dc motor? A. The type of armature B. The method of excitation C. The number of armature coils D. The polarity of armature current and direction of magnetic flux
D. The polarity of armature current and direction of magnetic flux
What determines the magnitude of electric current? A. The rate at which electrons are produced B. The type of material used C. The current carrying capacity of the circuit D. The rate at which electrons pass a given point
D. The rate at which electrons pass a given point
The PUT is A. Not a thyristor B. Much like the UJT C. Not a four-layer device D. Trigger on and off by the gate-to-anode
D. Trigger on and off by the gate-to-anode
Which device exhibits negative resistance region? A. Diac B Transistor C. Triac D. UJT
D. UJT
What is the resistance level of a photodiode in total darkness? A. Very low B. High C. Low D. Very High
D. Very High
Find the Thevenin equivalent circuit at terminal a and b. A. Vth=100 V, Rth=500ohms B. Vth=150 V, Rth=400ohms C. Vth=200 V, Rth=400ohms D. Vth=150 V, Rth=500ohms
D. Vth=150 V, Rth=500ohms
___________ is a thin polished slice of a semiconductor crystal on which integrated circuit can be fabricated often in duplicate, for cutting into individual slice. A. Silicon B. Gallium C. Indium D. Wafer
D. Wafer
What are the two possible breakdown mechanisms in pn junction diodes? A. Reverse and breakdown effects B. Threshold and knee effects C. Avalanche and forward effects D. Zener and avalanche effects
D. Zener and avalanche effects
A theorem which states than an electric current flowing in a circuit produces a magnetic field at external points equivalent to that due to a magnetic shell whose bounding edge is the conductor and whose strength is equal to the strength of the current. A. joules' law B. faraday's law C. volta's theorem D. ampere's theorem
D. ampere's theorem
A current surge take place when a power supply is turned on because A. the transformer core is suddenly magnetize B. the diode suddenly start to conduct C. the filter capacitor must be initially charged D. arcing takes place in the power switch
D. arcing takes place in the power switch
Why is it that the magnitude of magnetomotive force required for air gap is much greater than that required from iron part of a magnetic circuit? A. because air is a gas B. because air has the highest relative permeability C. because air is a conductor of magnetic flux D. because air has the lowest relative permeability
D. because air has the lowest relative permeability
The gigabyte is a unit commonly used to measure of A. data access time B. data transfer time C. data communication accuracy D. data storage capacity
D. data storage capacity
Pure metals generally have A. low conductivity and zero temperature coefficient B. low conductivity and high temperature coefficient C. high conductivity and low temperature coefficient D. high conductivity and large temperature coefficient
D. high conductivity and large temperature coefficient
The input impedance of a MOSFET: A. is lower than the JFET B. is lower than the bipolar transistor C. is between that of the bipolar transistor and a JFET D. is extremely high
D. is extremely high
To measure power-supply voltage being used by a circuit, a voltmeter A. is placed in series with the circuit that works from the supply B. is place between the positive pole of the supply and the circuit working from the supply C. is place between the negative pole of the supply and the circuit working from the supply D. is place in parallel with the circuit that works from the supply
D. is place in parallel with the circuit that works from the supply
Hysteresis refers to the ___ between flux density of the material and the magnetizing force applied. A. ratio B. equality C. leading effect D. lagging effect
D. lagging effect
Which of the following voltmeter has the most inaccurate reading? A. low sensitive, 900 micro ohms B. low sensitive, 90 milli ohms C. low sensitive, 90 micro ohms D. low sensitive, 900 k ohms
D. low sensitive, 900 k ohms
A NAND gate is on only when all its inputs are A. on B. high C. positive D. off
D. off
A NOR gate is on only when all its inputs are A. on B. positive C. high D. off
D. off
The principal disadvantage of a voltage multiplier is A. excessive current B. excessive voltage C. insufficient rectification D. poor regulation
D. poor regulation
A changing magnetic field A. results from a steady electric current B. magnetizing the earth C. produce an electric current in the insulator D. produce a fluctuation electric field
D. produce a fluctuation electric field
The result of rust in electrical (wire) connection is A. inductance B. impedance C. conductance D. resistance
D. resistance
A small-signal amplifier A. always has an output signal in the mV range B. goes into saturation once on each input cycle C. is always a common-emitter amplifier D. uses only a small portion of its load line
D. uses only a small portion of its load line
When phase shifting an SCR, what two things must be phase shifted? A. variable resistor and gate current B. variable resistor and capacitor C. variable inductor and gate current D. variable capacitance and gate current
D. variable capacitance and gate current
In the figure shown, what is the current supplied by battery immediately after switching on the circuit? A. 1A B. 10A C. 4A D. 0
A. 1A
When a factor of a junction transistor is 0.98, the factor would be equivalent to __________ value of transistor's beta. A. 49 B. 20 C. 60 D. 38
A. 49
A resistor wound with a wire doubled back on itself to reduce the inductance. A. Bifilar resistor B. Wire-wound resistor C. Anti-inductive resistor D. Bleeder resistor
A. Bifilar resistor
Disc is made of what material in eddy current damping? A. Conductor and non-magnetic material B. Conductor and magnetic material C. Non-conductor and non-magnetic material D. Non-conductor and magnetic material
A. Conductor and non-magnetic material
On combinational circuit design, which of the following do not belong to Sense-Amplifier Circuits? A. Dual-Rail Domino B. Sample Set Differential Logic C. Differential Split-Level D. Differential Current Switch Logic
A. Dual-Rail Domino
How is the efficiency of a power amplifier determined? A. Efficiency = (RF power out/DC power in) x 100% B. Efficiency = (RF power in/RF power out) x 100% C. Efficiency = (RF power in/DC power in) x 100% D. Efficiency = (DC power in/RF power in) x 100%
A. Efficiency = (RF power out/DC power in) x 100%
A gain of -15dB in the circuit means A. The input signal is stronger than the output B. the output signal is stronger than the input C. the input signal is 15 times as stronger as the output D. the output signal is 15 times as stronger as the input
A. The input signal is stronger than the output
Consider two copper wires. One has twice the length of the other. How does the resistances of these two wires compare? A. The longer wire has twice the resistance of the shorter wire B. The longer wire has half the resistance of the shorter wire C. Both wires have the same resistance D. None of the above
A. The longer wire has twice the resistance of the shorter wire
What is the main advantage of temporary magnets? A. The magnetic flux can be changed B. Hysteresis can be decreased C. Magnetic materials can be used D. Abundance of ferromagnetic material that can be temporarily magnetized
A. The magnetic flux can be changed
How is the output of a differentiator related to the input in an op-amp? A. The output of a differentiator is proportional to the rate of change of the input. B. The output of a differentiator is inversely proportional to the rate of change of the input C. The two parameters are not related D. The two parameters are always equal to each other
A. The output of a differentiator is proportional to the rate of change of the input.
What is/are the purpose(s) of the PN junction diode? A. To rectify only B. To rectify and amplify C. To amplify only D. To switch
A. To rectify only
As the number of turns in a coil increases, the reactance: A. increases B. decreases C. stay the same D. is stored on the core material
A. increases
The power factor of a certain circuit in which the voltage lags behind the current is 80%. To increase the power to 100%, it is necessary to add ____________ to the circuit. A. inductance B. resistance C. capacitance D. impedance
A. inductance
Electron flow assumes charges flow from A. negative to positive B. negative to negative C. positive to negative D. positive to positive
A. negative to positive
When two coils of identical reactance are in parallel without mutual inductance, the reactance of the combination is _____________ the reactance of each coil. A. one half B. twice C. four times D. one fourth
A. one half
When both deflecting and controlling torque act, the pointer of an indicating instrument comes to A. rest B. mid-position C. maximum position D. three-fourth position
A. rest
Which of the following is not a characteristic of mica capacitors? A. high efficiency B. small size C. capability to handle high voltages D. low loss
B. small size
As the capacitor plate area decreases, all things being equal A. the capacitance increases B. the capacitance decreases C. the capacitance does not change D. the voltage-handling ability increases
B. the capacitance decreases
Drain current in the constant current region decreases when A. the gate-to-source bias voltage decreases B. the gate-to-source bias voltage increases C. the drain-to-source voltage increases D. the drain-to-source voltage decreases
B. the gate-to-source bias voltage increases
In a RAM: A. It's hard to get data out and easy to put it in B. It's easy to get data out and hard to put it in C. It's easy to get data out and put it in D. It's hard to get data out and put it in
C. It's easy to get data out and put it in
Magnetic flux can always be attributed to: A. Ferromagnetic materials B. Align atoms C. Motion of charge particles D. The geomagnetic fields
C. Motion of charge particles
The coefficient of coupling between two coils is a measure of what factor? A. The turns ratio of the coils B. The distance between the coils C. The relative positive of the coils D. The magnetic flux ratio linking the coils
D. The magnetic flux ratio linking the coils
The power rating of a transistor can be increased by A. Raising the temperature B. Using a derating curve C. Operating with no input signal D. Using a heat sink
D. Using a heat sink
For a UJT, the intrinsic standoff ratio is A. usually around 1k or so B. equal to 1 C. always greater than 1 D. always less than 1
D. always less than 1
Which of the following formulas is used to calculate the oscillating frequency of an LC oscillator? A. f=0.4/(2piLC)^2 B. f=1/(2pi(LC)^2 C. f=1/(2piRLC) D. f=1/(2pi(LC)^1/2)
D. f=1/(2pi(LC)^1/2)
At what frequency will the current lead the voltage by 30 degrees in a series circuit with R = 8ohms and C = 30uF? A. f=1109 Hz B. f=1123 Hz C. f=1178 Hz D. f=1149 Hz
D. f=1149 Hz
Hysteresis refers to the ___ between flux density of the material and the magnetizing force applied. A. leading effect B. ratio C. equality D. lagging effect
D. lagging effect
Power absorbed in a pure capacitive circuit is zero because A. reactive and active components of the current cancel out B. reactive component of the current is zero C. active component of the current is maximum D. power factor of the circuit is zero
D. power factor of the circuit is zero
The power in the reactance is: A. Radiated power B. True power C. Imaginary power D. Apparent power
C. Imaginary power
The voltage and current in an ac circuit are v=200sin(377t+30degrees) and i=10sin(377t+60degrees). Determine the average power. A. 822 W B. 866 W C. 938 W D. 892 W
B. 866 W
A device that reverses magnetic field polarity to keep a dc motor rotating is: A. A solenoid B. A commutator C. An armature coil D. A field coil
B. A commutator
Which of the following describes the speed of a dc motor? A. It is directly proportional to flux per pole B. It is inversely proportional to flux per pole C. It is inversely proportional to applied voltage D. It is inversely proportional to armature current
B. It is inversely proportional to flux per pole
An alternative name for a diac is: A. Silicon unilateral switch (SUS) B. Silicon bilateral switch C. Bidirectional trigger diode D. Four-layer diode
C. Bidirectional trigger diode
The v-i characteristics of a FET is shown in figure. In which region is the device biased for small signal amplification A. AB B. CD C. BC D. BD
C. BC
Power absorbed in a pure inductive circuit is zero because A. Reactive components of the current is zero B. Active components of the current is maximum C. Power factor of the circuit is zero D. Reactive and active components of the current cancel out
C. Power factor of the circuit is zero
In an ac circuit with inductive reactance, the A. phase angle of the circuit is always 45degrees B. voltage across the inductance must be 90degrees out-of-phase with the applied voltage C. current through the inductance lags its induced voltage by 90degrees D. current through the inductance and voltage across it are 180degrees out-of-phase
C. current through the inductance lags its induced voltage by 90degrees
Two RC coupled amplifiers are connected to form a 2 stage amplifier. If the lower and upper cutoff frequencies of each individual amplifier respectively are 100 Hz and 20 kHz, what these frequencies are for the 2 stage amplifier? A. 153.5 Hz and 12.3 kHz B. 145.5 Hz and 12.8 kHz C. 153.5 Hz and 11.3 kHz D. 155.5 Hz and 12.8 kHz
D. 155.5 Hz and 12.8 kHz
Determine how long a battery will last whose rating is 100Ah; 24Volts and will run a 300W electronic equipment and a 60W light. A. 3.33 hrs B. 6.33 hrs C. 3.67 hrs D. 6.67 hrs
D. 6.67 hrs