chapter 2 4k1 elecs
Loop currents should be assumed to flow in which direction A. Straight B. Clockwise C. Counter-clockwise D. Either B or C arbitrarily selected
D
Points to be considered in choosing a capacitor A. Working voltage B. Type of dielectric C. Capacitance D. All of the above
D
If three 9 mH inductors are connected in parallel without mutual inductance then the total inductance is A. 3 mH B. 9 mH C. 27 mH D. 18 mH
A
If two complex conjugates are added, components results. A. In-phase B. Quadrature C. Complex D. Out-of-phase
A
In a circuit, an active element is one which A. Supplies energy B. Receives energy C. Both supplies and receives energy D. Amplifies signal
A
In a complex number 5 + j 10, 10 is called part. A. Imaginary B. Real C. Conjugate D. Integer
A
In a multiple capacitor, the plate area is A. Increased B. The same C. Decreased D. Variable
A
In a pure capacitance, A. Current leads voltage by 90° B. Current leads voltage by 180° C. Current lags voltage by 90° D. Current lags voltage by 180° 97. The ohmic value of a resistor with
A
In a series RLC circuit A. The current lags VL by 90° B. The current leads VL by 90° C. XL leads Xc by90° D. Z = jXL at resonance
A
In a series circuit with unequal resistances the A. Highest R has the highest V B. Lowest R has the highest V C. Lowest R has the highest I D. Highest R has the highest I
A
What is a closed path made of several branches of the network called? A. Junction B. Node C. Terminal D. Loop
D
. "Any resistance R in a branch of a network in which a current I is flowing can be replaced by a voltage equal to IR". This states A. Compensation theorem B. Reciprocity theorem C. Millman's theorem D. Superposition theorem
A
. A capacitance of 6 µµF means A. 6 pF B. 6 nF C. 6 fF D. 6 aF
A
. In a resonant circuit, if Q 2: 10 resonant frequency bandwidth. A. Bisects B. Exceeds C. Is less than D. Is equal to
A
. The ratio of W/VA in an ac circuit means A. Power factor D. 90o B. Reactive factor C. Quality factor D. Load factor
A
. The voltage cannot be exactly in phase with the current in a circuit that contains A. Only capacitance B. Only resistance C. Inductance and capacitance D. Inductance, capacitance and resistance
A
. Which one of the following elements serves as a protection against overload? A. Fuse B. Switch C. Resistor D. Relay
A
.How many degrees of phase represents one full cycle? A. 360 B. 180 C. 270 D. 90
A
3. Which of the following is the most popular waveform? A. Sinusoidal B. Square wave C. Triangular D. Sawtooth
A
5. For a parallel AC circuit, is used as a reference phasor. A. Voltage B. Power C. Current D. Resistance
A
What is the reading of an ohmmeter for a shorted capacitor? A. Zero B. Infinity C. k n D. M n
A
A capacitive load always has a power facto A. Leading B. Lagging C. Zero D. Unity
A
A capacitor is basically constructed of A. Two conductors separated by a dielectric B. Two dielectric separated by a conductor C. Conductors and dielectric D. Conductors and semiconductors
A
A capacitor is used to A. Block dc current B. Pass dc current C. Open voltage source D. Short the voltage source
A
A capacitor opposes change in A. Voltage B. Current C. Voltage and current D. Neither voltage nor current
A
A circuit whose parameters change with voltage or current. A. Non-linear circuit B. Linear circuit A. CV2 /2 C. Complex circuit D. Passive circuit
A
A coil of inductance L has an inductive reactance of XL in an ac circuit in which the effective current is I. The coil is made from a superconducting material. The rate at which power is dissipated in the coil is A. 0 B. I 2 XL C. IXL D. IXL
A
A lead conductor has a resistance of 25 n at 0 °C. Determine its resistance at -30 °C A. 22 Q B. 24 n C. 12 n D. 11 n
A
A neon glow lamp used as a night light ionizes at approximately A. 70 V B. 80 V A. Q2 /V C. 90 V D. 100 V
A
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
A rheostat is a form of A. Variable resistor B. Variable capacitor C. Potentiometer D. Thermocouple
A
A series RL circuit has R of 10 Q and XL of 5 Q, its impedance in rectangular form is given by A. 10 + j s n B. 10 + j 10 Q C. 10 - j 5 Q D. 10 - j 10
A
A series RLC circuit consists of a 10 Q resistor in series with L = 10 µH, and C = 100 µF. Determine a new value of I, for which the resonant frequency is one -half the original value. A. 40 µH B. 40 mH C. 40 pH D. 40 nH
A
A series-parallel combination of identical resistors will A. Increase the power rating compared with one resistor alone B. Increase the voltage rating compared with one resistor alone C. Reduce the voltage rating compared with resistor alone D. Result in an expensive circuit
A
A tank circuit is a A. Parallel LC circuit B. Series LC circuit C. A resonant circuit D. A non-resonant circuit
A
A term used to express the amount of electrical energy stored in electrostatic field. A. Joules B. Coulombs C. Watts D. Electron-volt
A
A wire of one kilometre length has a resistance of 20 n. If the length is halved, then the the new resistance is the original resistance. A. Half B. Twice C. One-fourth D. Three times
A
According to Gauss theorem, flux can be equated to A. Charge B. Field intensity C. Current D. Voltage
A
An alloy composed of 84 % copper, 12 % manganese and 4 % nickel. A. Manganin B. Constantan C. Nichrome D. German silver wire
A
An inductance of 1 mH is A. 0.001 H B. 0.01 H C. 0.0001 H D. 0.10 H
A
An inductor carries 2 A dc. If its inductance is 100 µH, then what is its inductive reactance? A. Zero B. 1.3 kn C. 628 n D. -628 n
A
An intermittent and non-symmetrical alternating current like that obtained from the secondary winding of an induction coil A. Faradic current B. Transient ac current C. Inductive current D. Capacitive current
A
Another term of the quality factor of the resonant circuit. A. Figure of merit B. Figure of demerit C. Noise factor D. Noise figure
A
At what frequency will an inductor of 5mH have the same reactance as a capacitor of 0.1 µF? A. 7.12 kHz B. 7.12 Hz C. 7.12MHz D. 7.12 GHz
A
At what frequency will the current in a series RLC circuit reach its maximum value for an applied voltage of 15 V with R = 500 n, L = 100 µH and C = 0.001 µF? A. 503 kHz B. 403 kHz C. 603 kHz D. 303 kHz
A
Barium-strontium titanite dielectric material is also called A. Ceramic B. Polyster C. Electrolytic D. Bakelite
A
Capacitance increase with A. Larger plate area and less distance between plates B. Larger plate area and greater distance between plates C. Smaller plate area and less distance between plates D. Higher values of applied voltage
A
Conventional flow assumes charges flow from A. Positive to negative B. Positive to positive C. Negative to positive D. Negative to negative
A
Electron flow assumes charges flow from A. Negative to positive B. Negative to negative C. Positive to negative D. Positive to positive
A
For a carbon composition resistor, typical resistance values range from A. 2.7 Q to 22 MQ B. 1000 n to 10000 n C. 10 n to 10Mn D. 2.7 n to 2.7Gn
A
For a linear circuit, voltage or current is used to calculate average power. A. Rms B. Peak C. Average D. Instantaneous
A
For a series AC circuit, is not used as a reference phasor. A. Voltage B. Impedance C. Current D. Conductance
A
For multi-plate capacitor, capacitance is proportional to A. Number of plates less one(n - 1) B. Number of plates plus one(n + 1) C. Number of plates less two(n - 2) D. Number of plates (n)
A
For parallel capacitors, total charge is A. The sum of individual charges B. Equal to the charge of either capacitors C. Equal to the product of the charges D. The quotient of the charges
A
How many coulombs are delivered by a storage battery in 25 hours if it is supplying current at the rate of 3 A? B. 2.592 x 103 C C. 2.592 x 108 C D. 2.592 x 1012 C 184. When frequen
A
If a coil has a Q of 10, it means that A. The energy stored in the magnetic field of the coil is 10 times the energy wasted in its resistance B. The energy wasted in its resistance is 10 times the energy stored in the magnetic field of the coil C. It is a low Q coil D. It is a high Q coil
A
If one resistance in a series connection is open, then A. The current is zero in all the other resistances B. The current is maximum in all the other resistances C. The voltage is zero across the open resistance D. The voltage is infinite across the open resistance
A
If resonant frequency is 10 kHz and quality factor is 50, then A. Bandwidth is 200 Hz B. XL = is 50,000n C. R is 50 n D. XC = is 50,000n
A
If the output resistance of a voltage source is 4 Q, it internal resistance should be A. 4 n B. 8 Q C. 2 Q D. Infinite
A
In an RL series circuit, A. Current lags voltage by less than 90° B. Current lags voltage by 180° C. Current lags voltage by 90° D. Current leads voltage by 90°
A
In an inductive coil, the rate of rise of current is maximum A. Near the final maximum value of current B. At mid-value of current C. At half-power points D. After one time constant
A
In calculating maximum instantaneous power voltage or current is used. A. Peak B. Average C. Rms D. Instantaneous
A
In dividing or multiplying phasor quantities, form is used. A. Polar B. Rectangular C. Trigonometric D. Exponential
A
In the 5-band method of capacitor color coding, the first band indicates A. Temperature coefficient B. Tolerance C. 1st digit D. Capacitance value
A
It is impossible to change the voltage across a capacitor instantly, as this would produce current. A. Infinite B. Zero C. Low D. High
A
Leakage resistance in a capacitor results into A. Internal heating B. Internal bleeding C. Shorter useful life D. Short-circuiting
A
Of the equivalent combination of units, which one is not equal to watt? A. Q2 /V B. AV C. A2 Q D. J/s
A
Permeability is otherwise known as A. Magnetic conductivity B. Magnetic susceptibility C. Electric conductivity D. Electric susceptibility
A
Rationalizing the denominator of a complex number means A. Eliminating the j component in the denominator B. Adding j component in the denominator C. Eliminating the j component in the numerator D. Adding j component in the numerator
A
The Q-factor of a parallel resonant circuit is also known as A. Current magnification factor B. Voltage magnification factor C. Load factor D. Leakage factor
A
The arc across a switch when it open an RL circuit is a result of the A. Large self-induced voltage across L B. Long time constant C. Low resistance of the open switch D. Surge of resistance
A
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
The capacitance of a capacitor is relativepermittivity. A. Directly proportional to B. Inversely proportional to C. Equal to D. Inversely proportional to the square of
A
The charging of a capacitor through a resistance obeys A. Exponential law B. Logarithmic law C. Linear law D. Square law
A
The current is times the maximum current at half-power points of a resonance curve. A. 0.707 B. 1.414 C. 0.5 D. 0.632
A
The electric field strength between capacitor plates has a unit of A. Volts per meter B. Volts per mil C. Amperes per meter D. Amperes per miL
A
The farad is not equivalent to which of the following combination of units B. C2 /J C. C/V D. J/V2
A
The hot resistance of an incandescent lamp is about times its cold resistance. 2 A. 10 B. 5 C. 50 D. 100
A
The internal resistance of an ideal current source is A. Infinite B. Zero C. Equal to the load resistance D. To be determined
A
The of an alternating quantity is defined as the fractional part of a period or cycle through which the quantity has advanced from selected origin. A. Phase B. Frequency C. Amplitude D. Waveform
A
The potential gradient in a cable is maximum in A. Conductor B. Outer sheath C. Insulation D. Uniformly all over
A
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. Capacitance C. Resistance D. Impedance
A
The ratio of the flux density to the electric field intensity in the dielectric is called A. Permittivity B. Field intensity C. Permeability D. Elasticity
A
The reactance curve is a plot of frequency versus for a series RLC circuit A. Current B. Voltage C. Gain D. Impedance
A
The reciprocal of a complex number is A. A complex number B. A real number C. An imaginary number D. A whole number
A
The resistance of an insulator when its temperature is increased. A. Decreases B. Remains the same C. Increases D. Varies
A
The rms value of a triangular or sawtooth waveform is times its peakvalue. A. 0.577 B. 0.500 C. 0.25 D. 0.707
A
The temperature coefficient of resistance of electrolytes is A. Negative B. Positive C. Zero D. Infinite
A
The temperature-resistance coefficient of pure gold is A. 0.0034 B. 0.0037 C. 0.0038 D. 0.0039
A
The usual load of a dc circuit is a/an A. Resistor B. Capacitor C. Inductor D. Both inductor and capacitor
A
The value of temperature coefficient (a) is dependent upon A. The nature of material and temperature B. The length of material C. The cross-sectional area of the material D. The volume of the material
A
Transient period is considered over after A. 5 T B. 1 r C. 100 r D. 6 r
A
Tungsten filament of bulbs has a hot resistance higher than its cold resistance due to its temperature coefficient which is A. Positive B. Negative C. Zero D. Infinite
A
Two complex numbers or phasors are said to be conjugate if they A. Differ only in the algebraic sign of their quadratic components B. Differ only in the algebraic sign of their real components C. Are equal in their real and quadrature components including algebraic signs D. Are equal in their real components but differ in their quadrature components including algebraic signs.
A
VL = VC in a series RLC circuitwhen A. The value of the impedance is minimum B. The power factor is zero C. The current leads the total voltage by 90° D. The total voltage is zero
A
Voltage resonance means A. Series resonance B. Parallel resonance C. Current magnification D. Gain magnification
A
What is considered as the most important value of a sine wave? A. Effective value B. Peak value C. Average value D. Instantaneous value
A
What is the conductance of a circuit having three 10 n resistors in parallel? A. 0.3 S B. 3.33 S C. 0.33 S D. 30 S
A
What is the efficiency under the conditions of maximum power transfer? A. 50 % B. 100 % C. 25 % D. 75 %
A
What is the form factor of a triangular wave? A. 1.16 B. 1.11 C. 1.73 D. 1.41
A
What is the most common non-sinusoidal waveform? A. Square wave B. Triangular wave C. Trapezoidal wave D. Sawtooth wave
A
What is the most convenient way of achieving large capacitance? A. By using multiplate construction B. By using air as dielectric C. By decreasing distance between plates D. By using dielectric of low permittivity
A
What is the peak factor for alternating current or voltage varying sinusiodally? A. 1.4142 B. 0.707 C. 0.636 D. 1.11
A
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
What is the specific resistance of a pure germanium? A. 55 !!-cm B. 55 !2-m C. 55 !2-mm D. 55 k!2-m
A
What is the time constant for L of 240 mH in series with R of 20 n? A. 12 ms B. 4.8 s C. 83.3s D. 12 s
A
What is the total effective capacitance of two 0.25 µF capacitors connected in series? A. 0.125 µF B. 1.25 µF C. 0.50 µF D. 2.5 if
A
What rating of a resistor determines its ability to absorb heat? A. Wattage B. Ohmic C. Current D. Voltage
A
When capacitors are connected in parallel, the total capacitance is A. Greater than the largest capacitor B. Smaller than the largest capacitor C. Smaller than the smallest capacitor D. Greater than the smallest capacitor
A
When capacitors are connected in series, the total capacitance is A. Smaller than the smallest capacitor B. Smaller than the largest capacitor C. Greater than any of the capacitor D. Greater than the largest capacitor
A
When frequency of an ac wave decreases, the value of XL in a coil A. Approaches zero B. Gets larger positively C. Gets larger negatively D. Stays constant
A
When resistance are connected in parallel, the total resistance is A. Less than the smallest resistance in the connection B. Greater than the smallest resistance in the connection C. Between the smallest and greatest resistance in the connection D. Increasing and decreasing depending upon the supply voltage
A
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. Capacitive C. Resistive D. Infinite
A
When the temperature of copper wire is increased its resistance is A. Increased B. Decreased C. Constant D. Zero
A
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
When two complex conjugates are subtracted, the result is a A. Quadrature component only B. Complex component C. In-phase component D. Real component
A
When voltage is applied across a ceramic dielectric the electrostatic field produced is 50 times greater than air dielectric. The dielectric constant of ceramic therefore is A. 50 B. 100 C. 16.67 D. 5
A
Which is considered as the effect of a dielectric material? A. Increasing capacitance B. Decreasing capacitance C. Reducing the working voltage D. Increasing the distance between the plates
A
Which of the following conditions is not true for a series RLC circuit at resonance? A. Z = jXL B. XL = XC C. The power factor is one D. The magnitude of Z is -/R2 + (XL - XC )2
A
Which of the following describes the action of a capacitor? A. Stores electrical energy B. Opposes changes in current flow C. Creates a dc resistance D. Converts ac to dc
A
Which of the following does not refer to electrical energy? A. Volt-ampere B. Joule C. Watt-second D. Volt-coulomb
A
Which of the following has negative temperature coefficient? A. Carbon B. Nickel C. Brass D. Constantan
A
Which of the following is a common material used in wire-wound resistors? A. Manganin B. Carbon C. Bronze D. German silver wire
A
Which of the following is a disadvantage of a wire-wound resistor? A. It has reactance in radio-frequency circuits B. It cannot handle much power C. It draws a large amount of current D. It cannot handle high voltage
A
Which of the following is also known as anti-resonant circuit? A. Parallel resonant circuit B. Series resonant circuit C. Tuned circuit D. Tank circuit
A
Which of the following is neither a basic physical law nor deliverable from one? A. Ohm's law B. Coulomb's law C. Kirchhoff's first law D. Kirchhoff's second law
A
Which of the following is not a factor affecting dielectric strength? A. Mass B. Moisture content C. Temperature D. Thickness
A
Which of the following represents the energy stored in a capacitor? A. CV^2 /2 B. 2Q^2 IC C. C^2 IV D. CV
A
Which statement is true about a passive circuit? A. A circuit with neither a source of current nor a source of potential difference B. A circuit with a voltage source C. A circuit with a current source D. A circuit with only resistance as a load 111. What is a closed path made of several branches
A
Which waveform in which the rms value and the mean value are equal? A. Square wave B. Triangular wave C. Sine wave D. Sawtooth
A
. An ac series circuit is composed of a resistance of 20 n, inductive reactance of 40 n, and a capacitive reactance of 15 n. If a current of 1 ampere is flowing, what is the applied voltage A. 320 V B. 32 V C. 220 V D. 22 V
B
. An open inductor has A. Zero resistance and infinite inductance B. Infinite resistance and zero inductance C. Infinite resistance and infinite inductance D. Zero resistance and zero inductance
B
. Resistor with colored bands in the body A. Wire-wound resistor B. Carbon-composition resistor C. Potentiometer D. Rheostat
B
. The unit of elastance is A. Farad B. Daraf C. Siemen D. Henry
B
.The ratio between the active power and the apparent power of a load in an ac circuit is called A. Quality factor B. Power factor C. Power ratio D. Power reactive
B
For a triangular and sawtooth waveform the rms voltage or current equals A. 0.707 times peak value B. 0.577 times peak value C. 0.577 times average value D. 0.707 times rms value
B
7.For greater accuracy, the value of phase angle 0 should be determined from A. Cos 0 B. Tan 0 C. Sin 0 D. Sec 0
B
A capacitance of 0.05 µF equals A. 0.05 x 106 F B. 0.05 x 10-6 F C. 0.05 x 10-12 F D. 0.05 x 1012 F
B
A law which states that when a constant electromotive force is applied to a circuit consisting of a resistor and capacitor connected in series, the time taken for the potential on the plates of the capacitor to rise to any given fraction of its final value depends only on the product of capacitance and resistance. A. Child's law B. CR law C. Coulomb's law D. Debye T3 law
B
A trigger circuit consisting of a capacitor of 0.01 µF is connected in series with a resistor. If the circuit requires 100 Vdc to operate, determine the value of the resistor when time constant is 0.009s. A. 900 Q B. 900 k!! C. 900 MQ D. 900 GQ
B
An inductive circuit of resistance 16.5 Q and inductance of 0.14 H takes a current of 25 A. if the frequency is 50 Hz, find the supply voltage. A. 1501 V B. 1174 V C. 1877 V D. 991 V
B
An inductive load always has a power factor A. Leading B. Lagging C. Zero D. Unity
B
An open resistor when checked with an ohmmeter reads A. Zero B. Infinite C. High but within the tolerance D. Low but not zero
B
For a series circuit, the higher the quality factor A. The greater the bandwidth B. The narrower the passband C. The broader the resonance curve D. The wider the passband
B
For series capacitors, total charge is A. The sum of individual charges B. Equal to the charge of either capacitors C. Equal to the product of the charges D. The quotient of the charges
B
If the capacitance of mica capacitor is 5 times the capacitance of air capacitor, then the relative permittivity of mica is A. 2.5 B. 5 C. 10 D. 25
B
In Norton's theorem, the short circuit current is obtained by A. Opening the load terminals B. Shorting the load terminals C. Opening the voltage source D. Shorting the voltage source
B
In a circuit, a passive element is one which A. Supplies energy B. Receives energy C. Both supplies and receives energy D. Attenuates signal
B
In a parallel bank with unequal branch resistances A. The highest R has the highest I B. The lowest R has the highest V C. The lowest R has the highest V D. The highest R has the highest V
B
In adding or subtracting phasor quantities, form is the most convenient. A. Polar B. Rectangular C. Trigonometric D. Exponential
B
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° C. Voltages across R and XL are 180° out-of-phase D. Voltage across R leads the voltage across XL by 90°
B
In an ac circuit with a resistive branch and an inductive branch in parallel, the A. Voltage across the inductance leads the voltage across the resistance by 90° B. Resistive branch current is 90° out of phase with the inductive branch current C. Resistive and inductive branch currents have the same phase D. Resistive and inductive branch currents are 180° out-of-phase
B
In an ac wave, 30 degrees of phase is of a cycle. A. ½ B. 1/12 C. 1/3 D. 1/30
B
In liquids and gases, ionization current results from a flow of A. Positive or negative ions B. Free electrons C. Ions that are lighter in weight than electrons D. Protons
B
Metal tin becomes superconductor at approximately A. 6 K B. 3.7 K C. 5 K D. 4.7 K
B
Norton's theorem is Thevenin's theorem. A. The same as B. The converse of C. Older that D. More accurate than
B
Norton's theorem is what form of an ac equivalent circuit? A. Voltage B. Current C. Both voltage and current D. Neither voltage nor current
B
Parallel resonant circuit is sometimes called as A. Acceptor circuit B. Rejector circuit C. Inductive circuit D. Capacitive circuit
B
Series resonant circuit is sometimes known as A. Rejector circuit B. Acceptor circuit C. Inductive circuit D. Capacitive circuit
B
The Q-factor of a parallel resonant circuit is also known as A. Current magnification factor B. Voltage magnification factor C. Load factor D. Leakage factor
B
The Q-factor of a parallel resonant circuit is also known as A. Voltage magnification factor B. Current magnification factor C. Gain magnification factor D. Resonance magnification factor
B
The average value of a triangular or sawtooth wave is times its peak value. A. 0.577 B. 0.500 C. 0.318 D. 0.637
B
The charge in the capacitor is stored at the A. Terminals B. Plates C. Dielectric D. Air
B
The maximum power transfer theorem is used in A. Power system B. Electronic system C. Refrigeration D. Air conditioning
B
The ohmic value of a resistor with negative temperature coefficient A. Increases with increasing temperature B. Increase with decreasing temperature C. Stays unchanged with temperature change D. Stays unaffected even with increasing temperature
B
The presence of an electric current is made known by A. Electric shock B. Effects produced C. Magnetic shock D. Flashing
B
The ratio of maximum value to the effective value of an alternating quantity is called A. Form factor B. Peak factor C. Dynamic factor D. Leakage factor
B
The reason why electrical appliances are connected in parallel. A. It is a simple circuit B. This makes the operation of appliances independent with each other C. This results in reduced power consumption D. All of the above
B
The second strip of an electronic resistor color-code represents A. The multiplier B. The second digit of the value C. The temperature D. The tolerance
B
The symbol Q refers to A. Resonance quotient B. Quality factor C. Power quotient D. Qualification test
B
Thevenin's theorem is what form of an equivalent circuit? A. Current B. Voltage C. Both current and voltage D. Neither current nor voltage
B
Under the conditions of maximum power transfer, a voltage source is delivering a power of 15 W to the load. What is the power generated by the source? A. 60 W B. 30 W C. 15 W D. 4 W
B
What can be used to estimate resonant frequency and to find reactance at any frequency for any value of capacitor or inductor? A. Smith chart B. Reactance chart C. Impedance chart D. Resonance chart
B
What capacitance exists not through design but simply because two conducting surfaces are relatively close to each other? A. Surge B. Stray C. Natural D. Normal
B
What dielectric is generally employed by a variable capacitor? A. Mica B. Air C. Electrolyte D. Ceramic
B
What does a capacitor store? A. Voltage B. Charge C. Current D. Power
B
What is the peak factor of a triangular wave? A. 1.16 B. 1.73 C. 1.41 D. 1.11
B
What is the resonant frequency of a circuit when L of 25 microhenrys and C of 10 picofarads are in parallel? A. 10.1 kHz B. 10.1 MHz C. 101 MHz D. 101 kHz
B
What is the total capacitance of 10 capacitors, each of 20 µF in series? A. 200µF B. 2 µF C. 100 µF D. 0.5 µF
B
What is the value of a carbon composition resistor with the following color code: Brown, white, orange, red A. 190 Q; 10 % B. 19 kQ; 2 % C. 19 kQ; 20 % D. 1.9 kQ; 2 %
B
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
When current and voltage arte in phase in an ac circuit, the is equal to zero. A. Resistance B. Reactance C. Inductance D. Capacitance
B
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
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. Twice C. Four times D. One-fourth
B
When two unequal values of resistors are connected in parallel across a dc source, greater current flows through the A. Higher resistance B. Lower resistance C. Higher wattage resistance D. Lower wattage resistance
B
Which of the following dielectric materials makes the highest-capacitance capacitor? A. Air B. Barium-strontium titanite C. Mica D. Electrolyte
B
Which of the following has a positive temperature coefficient? A. Mica B. Manganin C. Silicon D. Carbon
B
Which of the following is a preferred resistor value? A. 520 B. 47 C. 43,000 D. 54,321
B
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
Which of the following is not a factor affecting capacitance of a basic capacitor? A. Area of plates B. Number of plates C. Distance between plates D. Dielectric material used
B
Which of the following is the statement of Ohm's law? A. Electric current is directly proportional to both voltage and resistance B. Electric current varies directly as the voltage and inversely as the resistance C. Electrical power is directly proportional to the resistance and inversely as the current squared D. Electrical power is directly proportional to both voltage squared and the resistance
B
Which of the following materials has the lowest dielectric strength? A. Glass B. Paper C. Mica D. Teflon
B
he mutual inductance between two coils is the reluctance of magnetic path. A. Directly proportional to B. Inversely proportional to C. Independent to D. Equal to
B
. A gang capacitor is a variable capacitor in which capacitance is varied by changing the A. Dielectric B. Number of plates C. Plate area D. Distance between plates
C
. Two capacitors of capacitance 9 µF and 18 µF in series will have a total capacitance of A. 27 µF B. 162 µF C. 6 µF D. 180 µF
C
2.What theorem is generally used in the analysis of vacuum tubes? A. Superposition theorem B. Millman's theorem C. Thevenin's theorem D. Norton's theorem
C
A 0.09 microfarad capacitor is charged to 220 volts. How long in milliseconds will it discharged resistor has a resistance of 20,000 ohms? A. 1.5 B. 2.5 C. 1.25 D. 0.5
C
A 5 µF capacitor charge to 5V has a stored charge equal to A. 1 µc B. 5 µc C. 25 µC D. 200 µc
C
A capacitor consists of two A. Conductors only B. Dielectric only C. Conductors separated by a dielectric D. Dielectric separated by a conductor
C
A capacitor of 0.5 µF charged to 220 V is connected across an uncharged 0.5 µF capacitor. What is the voltage across each capacitor? A. 220 V B. 150 V C. 110 V D. 22 V
C
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
A real current source has A. Infinite internal resistance B. Zero internal resistance C. Large internal resistance D. Small internal resistance
C
A switch designed to have low capacitance between its terminal when open. A. LOCAP switch B. AntiLOCAP switch C. Anticapacitance switch D. Capacitance switch
C
A three-by-three, series-parallel matrix of resistors, all having the same ohmic value, would have a net resistance of A. One-third the value of a single resistor B. Three times the value of a single resistor C. The same value as a single resistor D. Nine times the value of a single resistor
C
A trimmer is a variable capacitor in which capacitance is varied by changing the A. Number of plates B. Dielectric C. Distance between plates D. Plate area
C
An electric circuit contains A. Passive elements B. Active elements C. Both active and passive elements D. Reactive elements
C
And ideal current source has an internal conductance of -----siemen(s) A. Infinite B. One C. Zero D. One million
C
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
Delta to wye or wye to delta transformation technique is applied to a network. A. One-terminal B. Two-terminal C. Three-terminal D. Complex
C
What is the temperature coefficient of the resistance Eureka? A. Infinity B. Negative C. Almost zero D. Positive
C
Electric energy refers to A. Volt divided by coulomb B. Volt-ampere C. Volt-coulomb D. Watt divided by time
C
For maximum power transfer, what is the relation between load resistance RL and internal resistance R of the voltage source? A. RL = 2 r B. RL = 1.5 r C. RL = r D. RL = 3 r
C
High resistance values are a consequence of the of the film. A. Thickness B. Length C. Thinness D. Area
C
If a capacitor is rated for 200V dc, what is its effective ac working voltage? A. 50 V B. 100 V C. 200 V D. 400 V
C
If a certain circuit has a current that is lagging the voltage by 45°, then it displays A. Pure inductive reactance B. Resistance and capacitance reactance C. Resistance and inductive reactance D. Pure capacitive reactance
C
If a multiplate capacitor has 10 plates, each of area 10 cm 2 , then A. 10 capacitors will be in parallel B. 10 capacitors will be in series C. 9 capacitors will be in parallel D. 9 capacitors will be in series
C
If an emf in circuit A produces a current in circuit B, then the same emf in circuit B produces the same current in circuit A. this theorem is known as A. Maximum power transfer theorem B. Millman's theorem C. Reciprocity theorem D. Norton's theorem
C
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
C
In a complex resistance-reactance plane, XL isrepresented A. By an axis opposite the R axis B. By an axis perpendicular to the XC axis C. By an axis opposite the XC axis D. By an axis parallel to the R axis
C
In a rectangular wave, the form factor is A. 1.11 B. 1.16 C. 1.0 D. 1.73
C
In a series RLC circuit A. Increasing the frequency decreases the resistance B. Increasing the frequency increases the resistance C. Both XL and XC change as frequencychanges D. Impedance will always decrease
C
In an ac circuit with inductive reactance, the A. Phase angle of the circuit is always 45° B. Voltage across the inductance must be 90° out-of-phase with the applied voltage C. Current through the inductance lags its induced voltage by 90° D. Current through the inductance and voltage across it are180° out-of-phase
C
In an ac circuit, the power dissipated as heat depends on A. Impedance B. Capacitive reactance C. Resistance D. Inductive reactance
C
Inductive reactance applies only to sine waves because it A. Increases with lower frequencies B. Increases with lower inductance C. Depends on the factor 2 1t D. Decreases with higher frequencies
C
Kirchhoff's laws (KCL and KVL) are applicable to A. DC circuits B. AC circuits C. DC as well as AC circuits D. Passive networks alone
C
Property of an electric circuit that dissipates electric energy A. Reactance B. Impedance C. Resistance D. Conductance
C
Refers to the outward-curving distortion of the lines of force near the edges of two parallel metal plates that form a capacitor. A. Skin effect B. Night effect C. Edge effect D. Hall effect
C
The capacitor opposes any change in voltage across it by A. Passing a voltage proportional to the rate of change of current B. Acting as a short circuit at time equal to zero C. Passing a current proportional to the rate of change of voltage D. Acting as a short circuit at time equal to infinityC
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
The graph between an alternating quantity and time is called A. Sine wave B. Curve C. Waveform D. A plot
C
The internal resistance of an ideal voltage source is A. Infinite B. Equal to the load resistance C. Zero D. To be determined
C
The reason why electrical appliances are not connected in series. A. Greater electrical power saving B. Power loss is minimum C. Appliances have different current ratings D. All of the above
C
The superposition theorem is used when the circuit contains A. Reactive elements B. Active elements C. Number of voltage sources D. Single voltage source
C
The voltage lags the current by n 2 cycle in a A. Purely resistive circuit B. Purely inductive circuit C. Purely capacitive circuit D. Circuit containing resistance, capacitance and inductance
C
The wavelength of an alternating waveform depends upon the of the variation. A. Period B. Number C. Frequency D. Amplitude
C
What fusion of elements is without chemical action between them? A. Mixture B. Compound C. Alloy D. Ionization
C
What increases the resistance of wire at high frequencies? A. Temperature B. Voltage C. Skin effect D. Insulation
C
What is expected when two 20 kn, 1 watt resistor in parallel are use instead of one 10 kn, 1 watt? A. Provides higher current B. Provides less power C. Provides more power D. Provides wider tolerance
C
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 MHz C. 16.5 kHz D. 165 kHz
C
What is the hot resistance of a 100 W, 220 V incandescent lamp? A. 2.2 n B. 22 n C. 484 n D. 4.84 n
C
What is the purpose of a load in an electric circuit? A. To increase the circuit current B. To decrease the circuit current C. To utilize electrical energy D. To make the circuit complete
C
What is the reciprocal of capacitance? A. Reluctance B. Susceptance C. Elastance D. Conductance
C
What is the reciprocal of quality factor? A. Power factor B. Reactive factor C. Dissipation factor D. 1/Q factor
C
What is the resonant frequency of a circuit when L of 3 microhenrys and C of 40 picofarads are in series? A. 14.5 kHz B. 145 MHz C. 14.5 MHz D. 145 kHz
C
What is the specific resistance of a pure silicon? A. 55 n-mm B. 55 n-m C. 55 n-cm D. 55 kn-m
C
What is the total resistance of a two equal valued resistors in series? A. The difference of both B. The product of both C. Twice as one D. The sum of their reciprocals
C
What refers to the lowest voltage across any insulator that can cause current flow? A. Conduction voltage B. Critical voltage C. Breakdown voltage D. Voltage capacity
C
When the power factor of a circuit is zero, A. Power absorbed is maximum B. Power absorbed is minimum C. Power absorbed is zero D. The impedance is minimum
C
When two pure sine waves of the same frequency and the same amplitude which are exactly 180° out-of-phase are added together, the result is A. A wave with twice the amplitude B. A wave with half the amplitude C. Zero signal D. A wave with twice the frequency
C
Which component opposes voltage change? A. Resistor B. Inductor C. Capacitor D. Transistor
C
Which of the following dielectric materials makes the lowest-capacitance capacitor? A. Paper B. Mica C. Air D. Electrolyte
C
Which of the following does not affect resistance? A. Resistivity B. Cross-sectional area C. Mass D. Length
C
Which of the following is not considered a physical factor affecting resistance? A. Length B. Material type C. Temperature D. Cross-sectional
C
Which of the following is the peakiest? A. Square wave B. Sinusoidal wave C. Triangular wave D. Rectangular wave
C
Which of the statements below is not true? A. Current source is an active element B. Resistor is a linear element C. Voltage source is a passive element D. Diode is a non-linear element
C
Which statement is true? A. A series resonant circuit is of high impedance B. A parallel resonant circuit is of low impedance C. A series resonant circuit is inductive if it operates at a frequency higher than the resonant frequency D. A parallel resonant circuit is inductive if it operates at a frequency higher than the resonant frequency
C
. If three 100-pF capacitors are connected in series, then the total capacitance is A. 300 pF B. 100 pF C. 50 pF D. 33.3 pF
D
. If two equal resistances connected in series across a certain supply are now connected in parallel across the same supply, the power produced will be that of series connection A. One-half B. One-fourth C. Two times D. Four times
D
.The factor 0.707 for converting peak to rms applies only to A. Square waves B. Triangle waves C. Sawtooth waves D. Sine waves
D
At parallel resonance, the currents flowing through L and C are A. Infinite B. Zero C. Unequal D. Equal
D
A capacitor requires 12 µC of charge to raise its potential of 3 V. What is the capacitance of the capacitor? A. 36 µF B. 15 µF C. 0.25 µF D. 4µF
D
A factor that states how much the resistance changes for a change in temperature? A. Resistivity B. Specific resistance C. Coefficient of temperature change D. Temperature coefficient of resistance
D
A series RLC circuit has a power factor at its half-power points A. Unity B. Leading C. Lagging D. Either B or C
D
An impedance given by 90L-45° is a/an impedance. A. Inductive B. Conductive C. Resistive D. Capacitive
D
Another term for superconductor. A. Generic conductor B. Ultraconductor C. Cryotron D. Cryogenic conductor
D
Effects of capacitance A. It opposes any change in the amount of voltage B. Voltage is lagged behind the current by a quarter cycle C. Electric energy is stored in the capacitor in the form of electrostatic field D. All of the above
D
Form its definition, the unit of electric field, { is the N/C and equivalent unit of { is the A. V(m)2 B. V(m) C. V/m2 D. V/m
D
If two resistances of 9 Q and 6 Q are connected in parallel, the total resistance is A. 54 Q B. 0.3 Q C. 15 Q D. 3.6 Q
D
If voltage across the plates of 2 F capacitor is increased by 4 V, then charge on the plates will A. Decrease by 2 C B. Increase by 2 C C. Decrease by 4 C D. Increase by 4 C
D
In a rectangular wave, the peak factor is A. 1.16 B. 1.73 C. 1.11 D. 1.0
D
Liquids that are good conductors because of ionization are called A. Electrolytic B. Bases C. Acid D. Electrolytes
D
Refers specifically to steady state values of quantities in ac circuits which are complex numbers. A. Domain B. Scalar quantity C. Vector quantity D. Phasor quantity
D
Series resonance occurs when A. XL = XC B. XL = R C. Z = R D. Both A and C
D
The admittance of a parallel RLC circuit is found to be the sum of conductance and susceptances. A. Algebraic B. Arithmetic C. Vector D. Phasor
D
The charging of a capacitor through a resistance follows what law? A. Linear law B. Hyperbolic law C. Inverse-square law D. Exponential law
D
The curve between current and frequency is termed as A. Voltage curve B. Gain curve C. Power curve D. Resonance curve
D
The impedance in the study of electronics is represented by resistance and A. Inductance B. Capacitance C. Inductance and capacitance D. Reactance
D
The open-circuit voltage at the terminal of load RL is 60V. Under the condition of maximum power transfer, the load voltage will be A. 60 V B. 15 V C. 20 V D. 30 V
D
The power factor of a circuit is equal to A. RZ B. XC/Z C. XL/Z D. R/Z
D
The ratio between the reactive power and the apparent power of an ac load is called A. Quality factor B. Power factor C. Power ratio D. Reactive power
D
The reason why alternating current can induce voltage is A. It has 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
The result of rust in electrical (wire) connection is A. Inductance B. Conductance C. Impedance D. Resistance
D
What determines the direction of induced emf in a conductor or coil? A. Cork screw rule B. Fleming's left hand rule C. Ampere's circuital law D. Fleming's right hand rule
D
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
What is a rotating vector whose projection can represent either current or voltage in an ac circuit? A. Polar diagram B. Scalar quantity C. Velocity D. Phasor
D
What is the complex impedance of a circuit with an absolute resistance of 300 Q? A. 0 + j 300 Q B. 300 + j 90 Q C. 0 - j 300 Q D. 300 + j 0 n
D
What is the cross-sectional are of a conductor whose diameter is 0.001 inch? A. One micron B. One angstrom C. One steradian D. One circular mil
D
What is the other name of relative permittivity? A. Dielectric strength B. Potential gradient C. Breakdown voltage D. Specific inductance capacity
D
What refers to such work at very low temperatures, near absolute zero? A. Cryogenics B. Superconductivity C. Subsonic D. Thermionic
D
What theorem is usually used in the analysis of transistor circuit? A. Superposition theorem B. Millman's theorem C. Thevenin's theorem D. Norton's theorem
D
What value of R is needed with a 0.05 µF C for an RC time constant of 0.02 s? A. 400 n B. 400 Mn C. 400 Gn D. 400 k!!
D
Which factor does not affect resistance? A. Length B. Resistivity C. Cross-sectional area D. Mass
D
Which of the following capacitors are used only in dc circuits? A. Mica B. Ceramic C. Mylar D. Electrolytic
D
Which of the following capacitors has the highest cost per µF? A. Plastic B. Air C. Mica D. Electrolytic
D
Which of the following capacitors is suitable for dc filter circuits? A. Mica B. Ceramic C. Paper D. Electrolytic
D
Which of the following combination of length and cross-sectional area will give a certain volume of copper the least resistance? A. 2L and1/2 A B. Does not matter because the volume of copper remains the same C. L and A D. ½ L and 2 A
D
Which of the following does not generally affect the value of a capacitor? A. The dielectric material used B. The surface area of the plates C. The thickness of the dielectric D. The voltage applied to the plate
D
Which of the following elements is active? A. Resistor B. Inductor C. Capacitor D. Ideal voltage source
D
Why are inductance and capacitance not relevant in a dc circuit? A. Because it is a simple circuit B. Because dc circuits require only resistance as load C. Because they do not exist in a dc circuit D. Because frequency of dc is zero
D
With double the number of turns by the same length and area, the inductance is A. The same B. Doubled C. Quartered D. Quadrupled
D