1. Four equal resistors are connected parallelly with 5V power source across the circuit. If 2.5mA is measured from the source, the value of each resistor is equal to
a. 2 ohm
b. 4 ohm
c. 5 ohm
d. 8 ohm
2. The DC and AC values of β of the transistor are
a. Nearly equal to zero
b. Nearly equal to unity
c. Less than unity
d. Greater than unity
3. Which of the following statements is a wrong one?
a. Current gain provided by common collector configuration is much less than the circuit gain of common base configuration
b. Current gain provided by common collector configuration is much greater than the circuit gain of common base configuration
c. Current gain provided by common collector configuration is equal to the circuit gain of common base configuration
d. Current gain provided by common collector configuration is nearly equal to the circuit gain of common emitter configuration
4. Two types of breakdown mechanism of transistor are
a. Avalanche and Zener breakdowns
b. Zener and tunnel breakdowns
c. Zener and Reach-through breakdowns
d. Avalanche and Reach-through breakdowns
5. Why CE configuration is widely preferred for amplifier circuits?
a. Provides a voltage gain greater than unity
b. Provides a current gain greater than unity
c. Provides power gain greater than CC & CB configurations
d. All
6. A Push-pull amplifier can be constructed using
a. 2 NPN transistors
b. 2 PNP transistors
c. One PNP and one NPN transistor
d. Both a & b
7. The maximum theoretical efficiency of a push-pull amplifier is
a. 65%
b. 68.4%
c. 78.5%
d. 89.5%
8. The reference voltage VR in zero crossing detectors is found to be
a. 1 V
b. 12 V
c. 20 V
d. 200 V
9. An op-amp can be classified as
a. Linear amplifier
b. Low-voltage amplifier
c. Positive feed back amplifier
d. RC coupled amplifier
10. During discharge of a capacitor
I. Voltage across it decreases
II. Current decreases
III.Charge decreases
a. I & II
b. II & III
c. III only
d. I, II & III
11. Identify the negative resistance based oscillator
a. Hartley oscillator
b. Clap oscillator
c. Tunnel diode oscillator
d. Wein bridge oscillator
12. A capacitor that stores 1 coloumb at 10 V has a capacitance of
a. 10 µf
b. 1 µf
c. 0.1 µf
d. 0.1 f
13. To increase the capacitance of acapacitor , the plates must be
a. Distanced
b. Brought closer
c. Smaller in size
d. Kept in series
14. Which one of the following exhibits non-ohmic resistance?
a. Aluminum
b. Silver
c. Copper
d. Diode
15. Due to the negative feedback, an amplifier circuit experiences
a. Reduced harmonic distortion
b. Reduced bandwidth
c. Increased noise ratio
d. All
16. Class B amplifier has less efficiency compared to
a. Class A
b. Class AB
c. Class C
d. All
17. The phase angle θ of an RLC circuit is
a. Arctan((XL+Xc)/R)
b. Arctan((XL-Xc)/R)
c. Arctan(XL/R)
d. Arctan((XL/Xc)/R)
18. In parallel RL circuit
a. The inductive current is real and lies on the +j axis
b. The inductive current is imaginary and lies on the +j axis
c. The inductive current is real and lies on the -j axis
d. The inductive current is imaginary and lies on the -j axis
19. Which one of the transistor configurations provides the maximum power gain?
a. Common emitter
b. Common base
c. Common collector
d. Both a & b
20. The FET can be used as voltage controlled current source when
a. The gate is grounded
b. The gate is shorted to drain
c. The gate is shorted to source
d. The gate is left free
21. Common collector transistor configuration is best suited for
a. Input stage of multistage amplification
b. Audio signal amplification
c. Video signal amplification
d. Impedance matching
22. The width of the channel of the JFET can be controlled by varying
a. Source voltage
b. Drain voltage
c. Gate voltage
d. Emitter voltage
23. A complementary symmetry class B amplifier has
a. Two NPN transistors
b. Two PNP transistors
c. One NPN and one PNP transistors
d. Cascaded emitter-follower network
24. A push-pull transformer coupled class B amplifier is a\same as complementary class B amplifier except
a. It is transformerless
b. Enhanced efficiency
c. Impedance matching property
d. High gain characteristics
25. An inverting amplifier has Rf = 2 Mohm and R=2kohm, its scale factor is
a. +1000
b. -1000
c. +100
d. -100
26. The output frequency of wein bridge oscillator corresponds to
a. Audio range
b. Microwave range
c. Radio frequency range
d. Supersonic range
27. An instrument amplifier is used for
a. Amplifying a signal from Vcb
b. Amplifying a signal from an oscillator
c. Amplifying a signal from transducer
d. None
28. Two resistors of 4 ohms and 12 ohms are connected in parallel. Their combined resistance R is
a. 3 ohm
b. 4 ohm
c. 5 ohm
d. 9 ohm
29. Resistors are said to be connected in series when
a. All carry the same value of current
b. Total current is equal to the sum of branch currents
c. Sum of potential drops across all resistors forming a closed circuit equals to the emf applied across the circuit
d. The resistors are connected in an end –to –end chain so that current leaving one resistor enters the next in the chain
30. When a transistor is operated in cut-off and saturation regions, it acts as
a. Linear amplifier
b. Switch
c. Variable resistor
d. Variable capacitor
31. The superposition theorem is essentially base on the concept of
a. Quantity
b. Linearity
c. Reciprocity
d. On-linearity
32. In a series resonance circuit , the current at resonance
a. Is minimum
b. Is maximum
c. Zero
d. Oscillates between max and min values
33. Law of electrolysis was proposed by
a. Faraday
b. Newton
c. Seebeck
d. Peltier
34. Two parallel wires separated by a distance d carries a DC current I in the same direction. The magnetic field along a line running parallel to these wires and midway between them
a. Depends upon the current I
b. Is zero
c. Depends upon the distance d
d. Depends upon the permeability of the medium between the wires
35. Kirchhoff’s first law at a junction deals with conservation of
a. Energy
b. Momentum
c. Power
d. Charge
36. The mobility of an electron in a conductor is expressed in terms of
a. Sqcm/Vs
b. Cm/Vs
c. Sqcm/V
d. Sqcm/s
37. When R=10 ohm, Xc=18 ohm & Xc=12 ohm, then the current
a. Leads the applied voltage
b. Lags behind the applied voltage
c. Is in phase with the applied voltage
d. None
38. If the power factor is zero, the current to the reactive load is
a. 90 out of phase with voltage
b. 180 out of phase with voltage
c. 360 out of phase with voltage
d. None
39. To use FET as an amplifier, it is operated in
a. Ohmic region
b. Active region
c. Saturation region
d. Cutoff region
40. The practical unit of transconductance gm ¬ is
a. mS
b. mA/V
c. mV
d. both a & b
41. JFET can be used as
a. Voltage source
b. Voltage variable resistor
c. Voltage independent resistor
d. Voltage sink
42. For power amplifiers, the use of MOSFET is more advantageous than the use of transistor because of
a. Less cost
b. Simplified biasing
c. High efficiency
d. Elimination of thermal runaway
43. Which one of the following is voltage independent device?
a. BJT
b. FET
c. JFET
d. MOSFET
44. For a class A amplifier, the maximum collector efficiency is
a. 35 %
b. 50 %
c. 75%
d. 90.1%
45. When a transistor is operated in cutoff and saturation region it acts like a
a. Linear amplifier
b. Switch
c. Variable resistor
d. Variable capacitor
46. The quality factor of a coil is given by
a. Q=ώL/R
b. Q=ώLR
c. Q=R/ώL
d. Q=1/ώLR
47. The necessary condition for maintaining oscillation in an oscillator is
a. βA=1<0 data-blogger-escaped----------="" data-blogger-escaped-100hz="" data-blogger-escaped-10="" data-blogger-escaped-12.7="" data-blogger-escaped-18.5="" data-blogger-escaped-180="" data-blogger-escaped-1="" data-blogger-escaped-200v="" data-blogger-escaped-20="" data-blogger-escaped-23.3="" data-blogger-escaped-260="" data-blogger-escaped-27.7="" data-blogger-escaped-2="" data-blogger-escaped-2a="" data-blogger-escaped-360="" data-blogger-escaped-3="" data-blogger-escaped-3db="" data-blogger-escaped-48.="" data-blogger-escaped-49.="" data-blogger-escaped-4="" data-blogger-escaped-50.="" data-blogger-escaped-51.="" data-blogger-escaped-52.="" data-blogger-escaped-53.="" data-blogger-escaped-54.="" data-blogger-escaped-55.="" data-blogger-escaped-90="" data-blogger-escaped-a.="" data-blogger-escaped-a="" data-blogger-escaped-across="" data-blogger-escaped-all="" data-blogger-escaped-amp="" data-blogger-escaped-amps="" data-blogger-escaped-and="" data-blogger-escaped-angle="" data-blogger-escaped-answer="" data-blogger-escaped-around="" data-blogger-escaped-at="" data-blogger-escaped-average="" data-blogger-escaped-b.="" data-blogger-escaped-band="" data-blogger-escaped-be="" data-blogger-escaped-below="" data-blogger-escaped-between="" data-blogger-escaped-bilateral="" data-blogger-escaped-branch="" data-blogger-escaped-by="" data-blogger-escaped-c.="" data-blogger-escaped-case="" data-blogger-escaped-circuit="" data-blogger-escaped-codes="" data-blogger-escaped-correct="" data-blogger-escaped-cosine="" data-blogger-escaped-current="" data-blogger-escaped-d.="" data-blogger-escaped-depends="" data-blogger-escaped-diode="" data-blogger-escaped-dual="" data-blogger-escaped-effective="" data-blogger-escaped-equivalent="" data-blogger-escaped-excited="" data-blogger-escaped-exhibits="" data-blogger-escaped-factor="" data-blogger-escaped-frequency="" data-blogger-escaped-gain="" data-blogger-escaped-given="" data-blogger-escaped-half="" data-blogger-escaped-has="" data-blogger-escaped-i="" data-blogger-escaped-if="" data-blogger-escaped-ii="" data-blogger-escaped-in="" data-blogger-escaped-inductor="" data-blogger-escaped-is="" data-blogger-escaped-it="" data-blogger-escaped-l="" data-blogger-escaped-linearity="" data-blogger-escaped-list="" data-blogger-escaped-load="" data-blogger-escaped-loop="" data-blogger-escaped-match="" data-blogger-escaped-mesh="" data-blogger-escaped-netphase="" data-blogger-escaped-node="" data-blogger-escaped-none="" data-blogger-escaped-norton="" data-blogger-escaped-of="" data-blogger-escaped-one="" data-blogger-escaped-open="" data-blogger-escaped-out="" data-blogger-escaped-p-1="" data-blogger-escaped-p-4="" data-blogger-escaped-p="" data-blogger-escaped-phase="" data-blogger-escaped-power="" data-blogger-escaped-q-2="" data-blogger-escaped-q-3="" data-blogger-escaped-q="" data-blogger-escaped-r-2="" data-blogger-escaped-r-3="" data-blogger-escaped-r-4="" data-blogger-escaped-r-l-c="" data-blogger-escaped-r="" data-blogger-escaped-reciprocity="" data-blogger-escaped-recovery="" data-blogger-escaped-rectified="" data-blogger-escaped-resistive="" data-blogger-escaped-resonance="" data-blogger-escaped-reverse="" data-blogger-escaped-rms="" data-blogger-escaped-s-1="" data-blogger-escaped-s-3="" data-blogger-escaped-s-4="" data-blogger-escaped-s="" data-blogger-escaped-secant="" data-blogger-escaped-select="" data-blogger-escaped-series="" data-blogger-escaped-shift="" data-blogger-escaped-sine="" data-blogger-escaped-sinusoidal="" data-blogger-escaped-source="" data-blogger-escaped-square="" data-blogger-escaped-structure="" data-blogger-escaped-superposition="" data-blogger-escaped-symmetrical="" data-blogger-escaped-tangent="" data-blogger-escaped-tellegen="" data-blogger-escaped-the="" data-blogger-escaped-theorem="" data-blogger-escaped-to="" data-blogger-escaped-tree="" data-blogger-escaped-upon="" data-blogger-escaped-using="" data-blogger-escaped-v="" data-blogger-escaped-value="" data-blogger-escaped-variable="" data-blogger-escaped-voltage="" data-blogger-escaped-wave="" data-blogger-escaped-when="" data-blogger-escaped-width="" data-blogger-escaped-will="" data-blogger-escaped-with="">1
b. <1 data-blogger-escaped-1="" data-blogger-escaped-br=""> c. 1, 1
d. 1, <1 data-blogger-escaped-br=""> 56. A class A amplifier has a very high output impedance and if it has to be used for low impedance loads like loudspeaker, then it has to include
a. Transformer
b. Coupling capacitor
c. Diode with resistor in parallel
d. An inductor in series with capacitor
57. A cascade amplifier is
a. Two common emitter amplifier stage in series
b. Two commom base amplifier stage in series
c. Common emitter amplifier stage in series with common base amplifier stage
d. Common stage amplifier stage in series with common collector amplifier stage
58. The maximum efficiency possible in case of directly coupled series fed class A amplifier is
a. 25%
b. 50%
c. 75%
d. 98%
59. When amplifiers are subjected to AC signal of high frequency
a. The coupling capacitor acts as open circuit
b. The bypass capacitor acts as open circuit
c. The junction capacitance reduces the current gain
d. Has no effect on circuit capacitance
60. Positive going input signal becomes a negative going output signalin a
a. Common emitter
b. Common base
c. Common collector
d. None
61. The reverse biased PN junction exhibits a capacitance effect known as
a. Diffused capacitance
b. Translational capacitance
c. Transition capacitance
d. Differential capacitance
62. Which one is an RC phase shift based oscillator?
a. Colpitt’s oscillator
b. Wein bridge oscillator
c. Clap oscillator
d. Tunnel oscillator
63. If “turn on” time of a transistor is decreased, then its “turn-off” time
a. Increases
b. Decreases
c. Remains unchanged
d. Cannot be defined
64. A complementary symmetry amplifier has
a. A PNP and an NPN transistor
b. 2 PNP transistors
c. 2 NPN transistors
d. 2 N-channel FETs
65. The dc current output voltage drop from 48 V with no load is to 46 V at full load. Regulation is
a. 1.02%
b. 2.15%
c. 4.2%
d. 8.4%
66. High cut-off frequency can be expected from
a. Common collector amplifier
b. Common base amplifier
c. Common emitter amplifier
d. All
67. When a resistor R is connected to a current source, it consumes a power of 18 W. When the same resistor R is connected to a voltage source having the same magnitude as the current source, the power absorbed by resistor R is 4.5 W. The magnitude of the current source and the value of R are
a. √18 A & 1 ohm
b. 3 A & 2 ohm
c. 1 A & 18 ohm
d. 6 A & 0.5 ohm
68. The phasor combination of resistive power and reactive power is known as
a. True power
b. Average power
c. Apparent power
d. Reactive power
69. Currents I1, I2, & I3 meet at a junction (node) in a circuit. All currents are marked as entering the node. If I1=-6 sin(ώt) mA and I2=8 sin(ώt) mA tehn I3 will be
a. 10 cos(ώt+36.87) m A
b. 14 cos(ώt+36.87) m A
c. -14 sin(ώt+36.87) m A
d. -10 cos(ώt+36.87) m A
70. A source has an emf of 10 V and an impedance of 500+j100 ohm. The amount of maximum power transferred to the load will be
a. 0.05 m ohm
b. 0.05 ohm
c. 0.5 m ohm
d. 0.5 ohm
71. A cascade amplifier exhibits
a. High input impedance
b. High frequency performance
c. Good voltage gain
d. All
72. A decrease in base width of a transistor causes
X: The transport factor β and αdc to increase with increase in the magnitude off the collector junction voltage
Y: the charge gradient to increase with in the base, thus current due to minority carriers injected across the junction increases
Which of these statements occur(s)?
a. X only
b. Y only
c. Both X and Y
d. Either X or Y
73. Which of the following is/are not detectable by human ears?
a. Amplitude distortion
b. Frequency distortion
c. Phase distortion
d. Harmonic distortion
74. As the order of the harmonic frequency increases, its amplitude
a. Decreases
b. Increases
c. Is independent of harmonic frequency
d. Remains unaltered
75. A push-pull circuit requires
a. One transformer
b. One transformer which is center tapped
c. Two transformers which are centre tapped
d. No transformer for its operation
76. The forward biased PN junction exhibits a capacitive effect known as
a. Diffusion capacitance
b. Translational capacitance
c. Differential capacitance
d. Transition capacitance
77. Which parameter is widely used in transmission line theory?
a. Z parameter
b. Y parameter
c. ABCD parameter
d. H parameter
78. The voltage phasor of a circuit is 10∟15 V and the current phasor is 2 ∟-45 A. The active and reactive powers in the circuit are
a. 10 W & 17.32 V Ar
b. 5 W & 8.66 V Ar
c. 20 W & 60 V Ar
d. 20√2 W & 10√2 V Ar
79. Which of the following is apassive element?
a. Voltage source
b. Current source
c. Inductor
d. Transistor
80. A 555 timer can be used function as
a. Free running multivibrator
b. Monostable multivirator
c. Stable multivibrator
d. All
81. In an astable multivibrator, each stage is cut-off for 1 µs, and then the oscillation frequency is
a. 10 MHz
b. 5 MHz
c. 1 MHz
d. 0.5 MHz
82. When a 5 K ohm resistor , 200 ohm resistor , 1 Kohm resistor are in parallel , the total resistance is less than
a. 50 ohm
b. 100 ohm
c. 150 ohm
d. 170 ohm
83. Norton’s theorem is -------------- of Thevenin’s theorem.
a. Same as that
b. Equal
c. Converse
d. None
84. A constant AC voltage source
a. Has very high internal impedance as compared to external load impedance
b. Has very low internal impedance as compared to external load impedance
c. Has very high internal resistance as compared to external load impedance
d. Has very low internal resistance as compared to external load impedance
85. The maximum power transfer theorem is true for
a. AC power only
b. DC power only
c. Both AC and DC powers
d. Either AC or DC
86. When a human skin is moist or cut, its resistance to the flow of electricity
a. Is not affected at all
b. Remains same
c. Can increase drastically
d. Stray inductance
87. The collector output in a class C amplifier is a
a. Sine wave
b. Rectified sine wave
c. Pulse
d. Square wave
88. The collector output in aclass C amplifier is a
a. Sine wave
b. Rectified sine wave
c. Pulse
d. Square wave
89. In which class of amplifier transistor more or less acts like a switch
a. Class A
b. Class B
c. Class C
d. Class D
90. The static resistance of a PN junction germanium diode at a temperature 27 C having I=2.27mA for an applied forward bias of 0.3 volts is found to be
a. 13.2 *10^-5 ohm
b. 13.2 *10^-4 ohm
c. 13.2 *10^-3 ohm
d. 13.2 *10^-6 ohm
91. A potential difference of 400 volts is maintained across a capacitor of 25µf. The charge acquired by it is
a. 0.01 coulombs
b. 0.001 coulomb
c. 0.1 coulomb
d. 1 coulomb
92. In a Zener diode circuit , the supply voltage in a volts and the Zener current that can safely flow is 20 mA, then the value of series resistance R is found to be
a. 100 ohm
b. 150 ohm
c. 200 ohm
d. 250 ohm
93. The effect of rise in temperature is
a. To increase the resistance of pure conductors
b. To increase the resistance of alloys
c. To decrease the resistance of electrolytes
d. All
94. In a transistor, for normal operation, which of the following statements is/are correct?
Statement I: Collector and base must have same polarity with respect to emitter
Statement II: Collector and base must have opposite polarity with respect to emitter.
a. Statement I alone
b. Statement II alone
c. Both Statements I and II
d. Either Statement I or II
95. The expression IE=IB+IC is true for
a. NPN transistor
b. PNP transistor
c. Both NPN & PNP
d. Depends only on transistor configuration
96. For an NPN transistor
a. Ic = positive & IE=negative
b. Ic = negative & IE=positive
c. Both Ic & IE are positive
d. Both Ic & IE are negaitive
97. Pick out the wrong statement with respect to common-base amplifier
a. Very low input resistance
b. Very high output resistance
c. PHASE reversal between inputs & output voltages
d. Large voltage gain
98. Thyristor is derived from the words
a. Thyratron and transistor
b. Thyratron and resistors
c. Thyratrons and capacitors
d. Thyratrons and thermister
99. A transistor is said to be in saturation when
a. Ic(sat) = Vcc/R
b. VCE =0
c. VCC=Ic RL
d. All
100. A transistor is said to be in cut-off when
a. IB =0
b. IC=0
c. VCE=V
d. All
101. A series circuit is said to be in electrical resonance when its net reactance is
a. Unity
b. Zero
c. Infinity
d. Sinθ=1
102. Which is not a method used to solve circuits having impedance in parallel configuration?
a. Scale method
b. Vector method
c. Admittance method
d. Complex algebra method
103. The admittance method has two rectangular components and they are
a. Conductance and susceptance
b. Resistance and capacitor
c. Impedance and reactance
d. None
104. Identify the wrong relationship based on ohm’s law
a. I=V/R
b. R=V*V/W
c. V=√WR
d. I=V*V/R
105. During charging of the capacitor
I) Voltage across it rises
II) Charging increases
III) Charging current increases
Which of the following is/are not true?
a. I alone
b. II alone
c. III alone
d. I, II & III
106. Time constant of an RC circuit is defined as
a. The time during which capacitor voltage rises to 63.2% of its final value steady value
b. The time during which capacitor voltage rises to 70.7% of its final steady value
c. The time during which capacitor voltage rises to 50.5% of its final steady value
d. The time during which capacitor voltage rises to 10% of its final steady value
107. Ohm’s law is applicable to
a. DC circuits
b. AC circuits
c. AC & DC circuits
d. None
108. In an inductive circuit, the current rises according to the relation
a. i=
b. i=
c. i=
d. i=
109. The permeability of free space is
a. 4π*10^-7 H/m
b. 4π*10^-6 H/m
c. 4π*10^-3 H/m
d. 4π H/m
110. During discharge of a capacitor, which of he following decreases ?
a. Voltage across it
b. Charge in it
c. Current through it
d. All
111. Field strength has
a. Magnitude
b. Direction
c. Both magnitude and direction
d. Weight
112. In an inductive circuit, the current is expressed according to the rlation
a. I=IM[1-e^-t/λ]
b. I=IM[e^-t/λ]
c. I=IM-[e^-t/λ]
d. I=IM/e^-t/λ]
113. A power amplifier
a. Amplifies the power
b. Does not amplify the power
c. Is the first stage of an audio signal
d. None
b. <1 data-blogger-escaped-1="" data-blogger-escaped-br=""> c. 1, 1
d. 1, <1 data-blogger-escaped-br=""> 56. A class A amplifier has a very high output impedance and if it has to be used for low impedance loads like loudspeaker, then it has to include
a. Transformer
b. Coupling capacitor
c. Diode with resistor in parallel
d. An inductor in series with capacitor
57. A cascade amplifier is
a. Two common emitter amplifier stage in series
b. Two commom base amplifier stage in series
c. Common emitter amplifier stage in series with common base amplifier stage
d. Common stage amplifier stage in series with common collector amplifier stage
58. The maximum efficiency possible in case of directly coupled series fed class A amplifier is
a. 25%
b. 50%
c. 75%
d. 98%
59. When amplifiers are subjected to AC signal of high frequency
a. The coupling capacitor acts as open circuit
b. The bypass capacitor acts as open circuit
c. The junction capacitance reduces the current gain
d. Has no effect on circuit capacitance
60. Positive going input signal becomes a negative going output signalin a
a. Common emitter
b. Common base
c. Common collector
d. None
61. The reverse biased PN junction exhibits a capacitance effect known as
a. Diffused capacitance
b. Translational capacitance
c. Transition capacitance
d. Differential capacitance
62. Which one is an RC phase shift based oscillator?
a. Colpitt’s oscillator
b. Wein bridge oscillator
c. Clap oscillator
d. Tunnel oscillator
63. If “turn on” time of a transistor is decreased, then its “turn-off” time
a. Increases
b. Decreases
c. Remains unchanged
d. Cannot be defined
64. A complementary symmetry amplifier has
a. A PNP and an NPN transistor
b. 2 PNP transistors
c. 2 NPN transistors
d. 2 N-channel FETs
65. The dc current output voltage drop from 48 V with no load is to 46 V at full load. Regulation is
a. 1.02%
b. 2.15%
c. 4.2%
d. 8.4%
66. High cut-off frequency can be expected from
a. Common collector amplifier
b. Common base amplifier
c. Common emitter amplifier
d. All
67. When a resistor R is connected to a current source, it consumes a power of 18 W. When the same resistor R is connected to a voltage source having the same magnitude as the current source, the power absorbed by resistor R is 4.5 W. The magnitude of the current source and the value of R are
a. √18 A & 1 ohm
b. 3 A & 2 ohm
c. 1 A & 18 ohm
d. 6 A & 0.5 ohm
68. The phasor combination of resistive power and reactive power is known as
a. True power
b. Average power
c. Apparent power
d. Reactive power
69. Currents I1, I2, & I3 meet at a junction (node) in a circuit. All currents are marked as entering the node. If I1=-6 sin(ώt) mA and I2=8 sin(ώt) mA tehn I3 will be
a. 10 cos(ώt+36.87) m A
b. 14 cos(ώt+36.87) m A
c. -14 sin(ώt+36.87) m A
d. -10 cos(ώt+36.87) m A
70. A source has an emf of 10 V and an impedance of 500+j100 ohm. The amount of maximum power transferred to the load will be
a. 0.05 m ohm
b. 0.05 ohm
c. 0.5 m ohm
d. 0.5 ohm
71. A cascade amplifier exhibits
a. High input impedance
b. High frequency performance
c. Good voltage gain
d. All
72. A decrease in base width of a transistor causes
X: The transport factor β and αdc to increase with increase in the magnitude off the collector junction voltage
Y: the charge gradient to increase with in the base, thus current due to minority carriers injected across the junction increases
Which of these statements occur(s)?
a. X only
b. Y only
c. Both X and Y
d. Either X or Y
73. Which of the following is/are not detectable by human ears?
a. Amplitude distortion
b. Frequency distortion
c. Phase distortion
d. Harmonic distortion
74. As the order of the harmonic frequency increases, its amplitude
a. Decreases
b. Increases
c. Is independent of harmonic frequency
d. Remains unaltered
75. A push-pull circuit requires
a. One transformer
b. One transformer which is center tapped
c. Two transformers which are centre tapped
d. No transformer for its operation
76. The forward biased PN junction exhibits a capacitive effect known as
a. Diffusion capacitance
b. Translational capacitance
c. Differential capacitance
d. Transition capacitance
77. Which parameter is widely used in transmission line theory?
a. Z parameter
b. Y parameter
c. ABCD parameter
d. H parameter
78. The voltage phasor of a circuit is 10∟15 V and the current phasor is 2 ∟-45 A. The active and reactive powers in the circuit are
a. 10 W & 17.32 V Ar
b. 5 W & 8.66 V Ar
c. 20 W & 60 V Ar
d. 20√2 W & 10√2 V Ar
79. Which of the following is apassive element?
a. Voltage source
b. Current source
c. Inductor
d. Transistor
80. A 555 timer can be used function as
a. Free running multivibrator
b. Monostable multivirator
c. Stable multivibrator
d. All
81. In an astable multivibrator, each stage is cut-off for 1 µs, and then the oscillation frequency is
a. 10 MHz
b. 5 MHz
c. 1 MHz
d. 0.5 MHz
82. When a 5 K ohm resistor , 200 ohm resistor , 1 Kohm resistor are in parallel , the total resistance is less than
a. 50 ohm
b. 100 ohm
c. 150 ohm
d. 170 ohm
83. Norton’s theorem is -------------- of Thevenin’s theorem.
a. Same as that
b. Equal
c. Converse
d. None
84. A constant AC voltage source
a. Has very high internal impedance as compared to external load impedance
b. Has very low internal impedance as compared to external load impedance
c. Has very high internal resistance as compared to external load impedance
d. Has very low internal resistance as compared to external load impedance
85. The maximum power transfer theorem is true for
a. AC power only
b. DC power only
c. Both AC and DC powers
d. Either AC or DC
86. When a human skin is moist or cut, its resistance to the flow of electricity
a. Is not affected at all
b. Remains same
c. Can increase drastically
d. Stray inductance
87. The collector output in a class C amplifier is a
a. Sine wave
b. Rectified sine wave
c. Pulse
d. Square wave
88. The collector output in aclass C amplifier is a
a. Sine wave
b. Rectified sine wave
c. Pulse
d. Square wave
89. In which class of amplifier transistor more or less acts like a switch
a. Class A
b. Class B
c. Class C
d. Class D
90. The static resistance of a PN junction germanium diode at a temperature 27 C having I=2.27mA for an applied forward bias of 0.3 volts is found to be
a. 13.2 *10^-5 ohm
b. 13.2 *10^-4 ohm
c. 13.2 *10^-3 ohm
d. 13.2 *10^-6 ohm
91. A potential difference of 400 volts is maintained across a capacitor of 25µf. The charge acquired by it is
a. 0.01 coulombs
b. 0.001 coulomb
c. 0.1 coulomb
d. 1 coulomb
92. In a Zener diode circuit , the supply voltage in a volts and the Zener current that can safely flow is 20 mA, then the value of series resistance R is found to be
a. 100 ohm
b. 150 ohm
c. 200 ohm
d. 250 ohm
93. The effect of rise in temperature is
a. To increase the resistance of pure conductors
b. To increase the resistance of alloys
c. To decrease the resistance of electrolytes
d. All
94. In a transistor, for normal operation, which of the following statements is/are correct?
Statement I: Collector and base must have same polarity with respect to emitter
Statement II: Collector and base must have opposite polarity with respect to emitter.
a. Statement I alone
b. Statement II alone
c. Both Statements I and II
d. Either Statement I or II
95. The expression IE=IB+IC is true for
a. NPN transistor
b. PNP transistor
c. Both NPN & PNP
d. Depends only on transistor configuration
96. For an NPN transistor
a. Ic = positive & IE=negative
b. Ic = negative & IE=positive
c. Both Ic & IE are positive
d. Both Ic & IE are negaitive
97. Pick out the wrong statement with respect to common-base amplifier
a. Very low input resistance
b. Very high output resistance
c. PHASE reversal between inputs & output voltages
d. Large voltage gain
98. Thyristor is derived from the words
a. Thyratron and transistor
b. Thyratron and resistors
c. Thyratrons and capacitors
d. Thyratrons and thermister
99. A transistor is said to be in saturation when
a. Ic(sat) = Vcc/R
b. VCE =0
c. VCC=Ic RL
d. All
100. A transistor is said to be in cut-off when
a. IB =0
b. IC=0
c. VCE=V
d. All
101. A series circuit is said to be in electrical resonance when its net reactance is
a. Unity
b. Zero
c. Infinity
d. Sinθ=1
102. Which is not a method used to solve circuits having impedance in parallel configuration?
a. Scale method
b. Vector method
c. Admittance method
d. Complex algebra method
103. The admittance method has two rectangular components and they are
a. Conductance and susceptance
b. Resistance and capacitor
c. Impedance and reactance
d. None
104. Identify the wrong relationship based on ohm’s law
a. I=V/R
b. R=V*V/W
c. V=√WR
d. I=V*V/R
105. During charging of the capacitor
I) Voltage across it rises
II) Charging increases
III) Charging current increases
Which of the following is/are not true?
a. I alone
b. II alone
c. III alone
d. I, II & III
106. Time constant of an RC circuit is defined as
a. The time during which capacitor voltage rises to 63.2% of its final value steady value
b. The time during which capacitor voltage rises to 70.7% of its final steady value
c. The time during which capacitor voltage rises to 50.5% of its final steady value
d. The time during which capacitor voltage rises to 10% of its final steady value
107. Ohm’s law is applicable to
a. DC circuits
b. AC circuits
c. AC & DC circuits
d. None
108. In an inductive circuit, the current rises according to the relation
a. i=
b. i=
c. i=
d. i=
109. The permeability of free space is
a. 4π*10^-7 H/m
b. 4π*10^-6 H/m
c. 4π*10^-3 H/m
d. 4π H/m
110. During discharge of a capacitor, which of he following decreases ?
a. Voltage across it
b. Charge in it
c. Current through it
d. All
111. Field strength has
a. Magnitude
b. Direction
c. Both magnitude and direction
d. Weight
112. In an inductive circuit, the current is expressed according to the rlation
a. I=IM[1-e^-t/λ]
b. I=IM[e^-t/λ]
c. I=IM-[e^-t/λ]
d. I=IM/e^-t/λ]
113. A power amplifier
a. Amplifies the power
b. Does not amplify the power
c. Is the first stage of an audio signal
d. None
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