1. The
two windings of a transformer is linked B. inductively linked C. not linked at all D. electrically linked A. conductively
2.
A salient pole synchronous motor is running at no load. Its field current is switched off. The motor will A. come to stop B. continue
to run at synchronous speed to run at a speed slightly more than the synchronous speed D. continue to run at a speed slightly less than the synchronous speed C. continue
3. The
DC series motor should always be started with load because no load, it will rotate at dangerously high speed B. it will fail to start C. it will not develop high starting torque D. all is true A. at
4. In
a stepper motor the angular displacement be precisely controlled B. it cannot be readily interfaced with microcomputer based controller C. the angular displacement cannot be precisely controlled D. it cannot be used for positioning of work tables and tools in NC machines A. can
5. The
power factor of a squirrel cage induction motor is at light load only B. low at heavy load only C. low at light and heavy load both D. low at rated load only A. low
6. The
generation voltage is usually 11 KV and 33 KV B. between 132 KV and 400 KV A. between
C. between 400 KV and D. none of the above
700 KV
7. When
a synchronous motor is running at synchronous speed, the damper winding produces torque B. eddy current torque C. torque aiding the developed torque D. no torque A. damping
8. If
a transformer primary is energized from a square wave voltage source, its output voltage will be square wave B. a sine wave C. a triangular wave A. a
D.
a pulse wave
9. In
a DC series motor the electromagnetic torque developed is proportional to
A. Ia B. Ia
2
C. 1/Ia D. 1/Ia 10. In
2
a three phase induction motor running at slip ‘s’ the mechanical power developed in terms of air
gap power Pg is A. (s-1)P g
B. C. D.
Pg/(1-s) (1-s)Pg (s)(Pg)
11. In
a three phase induction motor the maximum torque proportional to rotor resistance r2 B. does not depend on r2 C. is proportional to sq. rt of r 2 2 D. is proportional to r 2 A. is
12. In
a DC machine, the armature MMF is w.r.t. armature B. rotating w.r.t. field C. stationary w.r.t. field D. rotating w.r.t. brushes A. stationary
13. In
a transformer the voltage regulation will be zero when it operates at p.f. B. leading p.f. C. lagging p.f. D. zero p.f. leading A. unity
14. The
maximum power in cylindrical and salient pole machines is obtained respectively at load angles
of A. 90
o
, 90o o
o
B. < 90 o , 90o C. 90 , > 90 D. 90 15. The
o
, < 90
o
EMF induced in the primary of a transformer in phase with the flux B. lags behind the flux by 90 degree C. leads the flux by 90 degree D. is in phase opposition to that of flux A. is
16. The
current from the stator of an alternator is taken out to the external load circuit through rings B. commutator segments C. solid connections D. carbon brushes A. slip
17. A
motor which can conveniently be operated at lagging as well as leading power factors is the
A.
squirrelrotor cage induction induction motor motor motor D. DC shunt motor B. wound
C. synchronous
18. A
hysteresis motor not a self-starting motor B. is a constant speed motor C. needs dc excitation D. cannot be run in reverse speed A. is
19. The
most suitable servomotor for low power applications is DC series motor B. a DC shunt motor C. an AC two-phase induction motor D. an AC series motor A. a
20. The
size of a conductor used in power cables depends on the voltage B. power factor C. current to be carried D. type of insulation used A. operating
21. Out
of the following methods of heating the one which is independent of s upply frequency is arc heating B. induction heating C. electric resistance heating A. electric
D. dielectric 22.
heating
In a DC shunt motor the terminal voltage is halved while the torque is kept constant. The resulting approximate variation in speed ' ' and armature current ' Ia ' will be and Ia are doubled A. Both is constant and Ia is doubled B. C. ω is doubled while Ia is halved is constant but Ia is halved D.
23.
An alternator is delivering rated current at rated voltage and 0.8 power-factor lagging case. If it is required to deliver rated current at rated voltage and 0.8 power-factor leading, the required excitation will be A. less B. more C. more or less D. the same
24. A
ceiling fan uses motor B. capacitor start and capacitor run motor C. universal motor D. capacitor start motor A. split-phase
25. A
stepper motor is DC motor B. a single-phase ac motor C. a multi-phase motor D. a two phase motor A. a
26. The
‘sheath’ is used in cable to strength to the cable B. provide proper insulation C. prevent the moisture from entering the cable D. avoid chances of rust on strands A. provide
27. The
drive motor used in a mixer-grinder is a motor B. induction motor C. synchronous motor D. universal motor A. DC
28. In
a three phase synchronous motor speed of stator MMF is always more than that of rotor MMF
A. the
B. the speed of stator MMF is always less than that of rotor MMF C. the speed of stator MMF is synchronous speed while that of rotor D. rotor 29. In
MMF is zero
and stator MMF are stationary with respect to each other
a capacitor start single-phase induction motor, the capacitor is connected series with main winding B. in series with auxiliary winding C. in series with both the windings D. in parallel with auxiliary winding A. in
30. A
synchro has three phase winding on rotor and a single-phase winding on stator B. a three phase winding on stator and a commutator winding on rotor C. a three phase winding on stator and a single-phase winding on rotor D. a single-phase winding on stator and a commutator winding on rotor A. a
31. As
the voltage of transmission increases, the volume of conductor
A.
increases not change
B. does
C. decreases D. increases
proportionately
32. The
size of the feeder is determined primarily by current it is required to carry B. the percent variation of voltage in the feeder C. the voltage across the feeder D. the distance of transmission A. the
33. The
boundary of the protective zone is determined by the of CT B. sensitivity of relay used C. location of PT D. none of these A. location
34.
In a three phase transformer, if the primary side is connected in star and secondary side is connected in delta, what is the angle difference between phase voltages in the two cases? A. delta side lags by -30° B. star side lags by -30° C. delta side leads by 30° D. star side leads by -30°
35. To
achieve low PT error, the burden value should be ____________.
A. low B. high C. medium D. none of the
above
36. The
synchronous reactance of the synchronous machine is ______________. between open circuit voltage and short circuit current at constant field current B. ratio between short circuit voltage and open circuit current at constant field current C. ratio between open circuit voltage and short circuit current at different field current D. ratio between short circuit voltage and open circuit current at different field current A. ratio
37. In
case of a universal motor, torque pulsation is minimized by _________. inertia B. rotor inertia C. both rotor and load inertia A. load
D.
none of the above
38. Oil-filled
cable has a working stress of __________ kV/mm.
A. 10 B. 12 C. 13 D. 15 39. Inverse
definite minimum time lag relay is also called ___________.
A.
pilot relay relay current relay D. directional overcurrent relay B. differential C. over
40. Mass
of a proton is how many times greater th an mass of an electron
A. 184000 B. 18400 C. 1840 D. 184 41.
The speed-torque characteristics of a DC series motor are approximately similar to those of the _________motor. A. universal B. synchronous C. DC shunt D. two-phase
42. The
torque-speed characteristics of an AC operated universal motor have ______ characteristic and it______ be started under no-load condition. A. an inverse, can B. a nearly inverse, can C. an inverse, cannot D. a nearly inverse, cannot
43.
In the heating process of the ________type a simple method of temperature control is possible by means of a special alloy which loses its magnetic properties at a particular high temperature and regains them when cooled to a temperature below this value. A. indirect induction over B. core type induction furnace C. coreless induction furnace D. high frequency eddy current
44. In
order to reduce the harmful effects of harmonics on the AC side of a high voltage DC transmission system ______are provided. A. synchronous condensers B. shunt capacitors C. shunt filters D. static compensators
45. An
AC tachometer is just ________with one phase excited from the carrier frequency. two-phase AC servomotor B. a two-phase induction motor C. an AC operated universal motor D. a hybrid stepper motor A. a
46. The
torque, in a _____________is proportional to the square of the armature current
A.
DC shuntmotor motor
B. stepper C. two D. DC 47.
phase servomotor series motor
The maximum power for a given excitation in a synchronous motor is developed when the power angle is equal to o A. 0 o B. 45 o C. 60 o D. 90
48. A
commutator in a DC machine power loss in armature B. reduces power loss in field circuit C. converts the induced AC armature voltage into direct voltage D. is not necessary A. reduces
49. The
speed of a DC shunt motor at no-load is ____________ higher than its speed at rated load. to 10% B. 15 to 20% C. 25 to 30% D. 35 to 40% A. 5
50. The
efficiency of a transformer is mainly dependent on losses B. copper losses A. core
C. stray losses D. dielectric losses 51. When
two transformers are operating in parallel, they will share the load as under: to their impedances B. inversely proportional to their impedances C. 50% - 50% D. 25%-75% A. proportional
52. If
the voltage is reduced to half, the torque developed by an induction motor will be reduced to ¼ of srcinal torque B. ½ of srcinal torque C. 1/8 of srcinal torque A.
D.
1/16 of srcinal torque
53.
o
If the phase angle of the voltage coil of a directional relay is 50 , the maximum torque angle of the relay is o A. 130 o B. 100 o C. 50 o D. 25
54.
A 220/440 V, 50 Hz, 5 KVA, single phase transformer operates on 220V, 40Hz supply with secondary winding open circuited. Then A. both eddy current and hysteresis losses decreases B. both eddy current and hysteresis losses increases C. eddy current loss remains the same but hysteresis loss increases D. eddy current loss increases but hysteresis loss remains the same 55. Which
of the following may be value of resistivity of copper? X 10 – 6 –5 B. 1.7 X 10 –4 C. 1.7 X 10 –3 D. 1.7 X 10 A. 1.7
56. The
introduction of inter poles in between the main pole improves the performance of DC machines, because A. the inter pole produces additional flux to augment the developed torque. B. the flux waveform is improved with reduction in harmonics. C. the inequality of air flux on the top and bottom halves of armature is removed. D. a counter EMF is induced in the coil undergoing commutation.
57. The
direction of rotation of hysteresis motor is reversed by shaded pole with respect to main pole B. reversing supply lead C. either A or B D. neither A nor B A. shift
58. Low
head plants generally use
A. Pelton Turbines B. Francis Turbine C. Pelton
or Francis Turbine
D. Kaplan Turbines 59. Electric
ovens using heating elements of _______________ can produce temperature up to 3000°C.
A. nickel B. graphite C. chromium D. iron
60. In
DC generators, armature reaction is produced actually by field current B. armature conductors C. field pole winding D. load current in armature A. its
61. Two
transformers operating in parallel will share the load depending upon their
A.
rating
B. leakage
reactance
C. efficiency D. per-unit impedance 62.
As compared to shunt and compound DC motors, the series DC motor will have the highest torque because of its comparatively ____________ at the start. A. lower armature resistance B. stronger series field C. fewer series turns D. larger armature current
63. Reduction
in the capacitance of capacitor-start motor, results in reduced
A. noise B. speed C. starting
torque reaction
D. armature
64. Regenerative
braking be used for stopping a motor B. cannot be easily applied to DC series motors C. can be easily applied to DC shunt motors D. cannot be used when motor load has overhauling characteristics A. can
65. At
present level of technology, which of the following method of generating electric power from sea is most advantageous? A. tidal power B. ocean C. ocean
thermal energy conversion currents D. wave power 66. If
the field circuits of an unloaded salient pole synchronous motor gets suddenly open circuited, then motor stops B. it continues to run at the same speed C. it runs at the slower speed D. it runs at a very high speed A. the
67. Electric
resistance seam welding uses __________ electrodes.
A. pointed B. disc C. flat D. domed 68. For LV
applications (below 1 kV), ______________ cables are used.
A.
paper insulated
B. plastic C. single
core cables
D. oil filled 69. No
load current in a transformer: the applied voltage by 90° B. lags the applied voltage by somewhat less than 90° C. leads the applied voltage by 90° D. leads the applied voltage by somewhat less than 90° A. lags
70. In
a salient pole synchronous machine (usual symbols are used): > xd B. xq = xd C. xq < xd D. xq = 0 A. xq
71. The
armature of a dc machine is laminated to reduce: current loss B. hysteresis loss C. copper losses D. friction and windage losses A. eddy
72.
The resistance representing mechanical output in the equivalent circuit of an induction motor as seen from the stator is: A. r2’[(1/s) – 1] B. r2’/s 2
C. r2 [(1/s) D. r2/s
– 1]
73. A
single phase Hysteresis motor run at synchronous speed only B. can run at sub synchronous speed only C. can run at synchronous and super synchronous speed D. can run at synchronous and sub synchronous speed A. can
74. The
temperature of resistance furnaces can be controlled by changing the:
A. applied voltage B. number C. circuit
of heating elements configuration
D.
all of the above
75. The
line trap unit employed in carrier current relaying: high impedance to 50 Hz power frequency signal B. offers high impedance to carrier frequency signal C. offers low impedance to carrier frequency signal D. both A & C A. offers
76. For
a line voltage V and regulation of a transmission line R
A.
Rα α (1/V) V
B. R
α V2 2 D. R α (1/V ) C. R
77. The
breakdown mechanism in a lightly doped p-n junction under reverse biased condition is called breakdown B. zener breakdown C. breakdown by tunneling D. high voltage breakdown A. avalanche
78.
In a CE-connected transistor amplifier with voltage-gain A , the capacitance C bc is amplified by a factor A. Av B. 1 + Av C. sq. rt. of (1 + A v) 2 D. Av
79. For
a large values of |VDS|, a FET behaves as controlled resistor B. current controlled current source C. voltage controlled current source D. current controlled resistor A. voltage
80. Removing
bypass capacitor across the emitter leg resistor in a CE amplifier causes in current gain B. decrease in current gain A. increase
C. increase in voltage gain D. decrease in voltage gain 81. For
an op-amp having differential gain A and common-mode gain Ac the CMRR is given by + Ac B. Av / Ac C. (Av / Ac) + 1 D. Ac / Av A. Av
82. When
a step-input is given to an op-amp integrator, the output will be ramp B. a sinusoidal wave C. a rectangular wave A. a
D.
a triangular wave with DC bias
83. Hysteresis
is desirable in Schmitt-trigger, because is to be stored/discharged in parasitic capacitances B. effects of temperature would be compensated C. devices in the circuit should be allowed time for saturation and desaturation D. it would prevent noise from causing false triggering A. energy
84. In
a full-wave rectifier without filter, the ripple factor is
A.
0.482
B. 1.21 C. 1.79
D. 2.05 85. The
minimum number of flip-flops required to construct a mod-75 counter is
A. 5 B. 6 C. 7 D. 8 86. Space
charge region around a p-n junction not contain mobile carriers B. contains both free electrons and holes C. contains one type of mobile carriers depending on the level of doping of the p or n regions D. contains electrons only as free carriers A. does
87. The
important characteristic of emitter-follower is input impedance and high output impedance B. high input impedance and low output impedance C. low input impedance and low output impedance D. low input impedance and high output impedance A. high
88. In
a JFET, at pinch-off voltage applied on the gate drain current becomes almost zero B. the drain current begins to decrease C. the drain current is almost at saturation value. A. the
D. the
drain-to-source voltage is close to zero volts
89. When
an amplifier is provided with current series feedback, its impedance increases and output impedance decreases B. input and output impedances both decrease C. input impedance decreases and output impedance increases D. input and output impedances both increase A. input
90. The
open-loop gain of an op-amp available in the market may be around.
A. 10
–1
B. 10 C. 10
5
D. 10
2
91.
The control terminal (pin5) of 555 timer IC is normally connected to ground through a capacitor (~0.01 F). This is to A. protect the IC from inadvertent application of high voltage B. prevent false triggering by noise coupled onto the pin C. convert the trigger input to sharp pulse by differentiation D. suppress any negative triggering pulse
92.
The value of ripple factor of a half-wave r ectifier without filter is approximately A. 1.2 B. 0.2 C. 2.2 D. 2.0 93. The
fan-out of a MOS-logic gate is higher than that of TTL gates because of its input impedance B. high output impedance C. low output impedance D. high input impedance A. low
94. In
an intrinsic semiconductor, the Fermi-level is to the valence band B. midway between conduction and valence band C. closer to the conduction band D. within the valence band A. closer
95. The
reverse – saturation current of a silicon diode for every 10°C increase in temperature B. does not change with temperature C. halves for every 1°C decrease in temperature D. increases by 1.5 times for every 2°C increment in temperature A. doubles
96. The
common collector amplifier is also known as follower B. base follower A. collector
C. emitter follower D. source follower 97. In
class –A amplifier, the output current flows for part of the cycle or the input signal B. the full cycle of the input signal C. half the cycle of the input signal D. 3/4th of the cycle of the input signal A. a
98. In
an amplifier with negative feedback the gain of the amplifier is affected B. only the gain and bandwidth of the amplifier are affected C. only the input and output impedances are affected A. only
D.
All of the four parameters mentioned above would be affected
99. Wien
bridge oscillator can typically generate frequencies in the range of – 1MHz B. 1 MHz – 10MHz C. 10MHz – 100MHz D. 100MHz – 150MHz A. 1KHz
100. A
differential amplifier, amplifies
A.
and differentiates mathematically differentiates the average of the voltages on the input lines the input waveform on one line when the other linetwo is grounded
B. and C. the
difference of voltages between the two input lines differentiates the sum of the two input waveforms
D. and 101. The
transformer utilization factor of a half-wave rectifier is approximately
A. 0.6 B. 0.3 C. 0.9 D. 1.1 102.
It is required to construct a counter to count up to 100 (decimal). The minimum number of flipflops required to construct the counter is A. 8 B. 7 C. 6 D. 5
103. The
power conversion efficiency of an output stage is defined as_______. power + supply power) / supply power B. (load power + supply power) / (load power - supply power) C. load power / supply power D. supply power / load power A. (load
104. A
highly stable resonance characteristic is the property of a ____ oscillator.
A. Hartley B. Colpitts C. Crystal D. Wien bridge 105.
The gate that assumes the 1 state, if and only if the input does not take a 1 state is called ________. A. AND gate B. NOT gate C. NOR gate D. Both B & C
106. The
width of depleted region of a PN junction is of the order of a few tenths of a ___________. A. millimeter B. micrometer C. meter D. nanometer
107.
For NOR circuit SR flip flop the not allowed condition is ________. A. S=0, R=0 B. S=0, R=1 C. S=1, R=1 D. S=1, R=0 108. In
negative feedback the return ratio is __________.
A. 0 B. 1 C. greater D. greater
than 0 than 1
109. A
phase shift oscillator uses __________________. tuning B. piezoelectric crystal C. balanced bridge D. variable frequency operation A. LC
110. The
voltage gain of basic CMOS is approximately _________.
A. (gmro)/2 B. 2gmro C. 1
/ (2gmro) / gm
D. 2ro
111. Transistor
is a controlled current device B. current controlled voltage device A. current
C. voltage controlled current device D. voltage controlled voltage device 112. A
bistable multivibrator is a running oscillator B. triggered oscillator C. saw tooth wave generator D. crystal oscillator A. free
113. For
a JFET, when VDS is increased beyond the pinch off voltage, the drain current
A. increases B. decreases C. remains
constant.
D.
first decreases and then increases
114. The
type of power amplifier which exhibits crossover distortion in its output is A B. Class B C. Class AB D. Class C A. Class
115. The
main advantage of a crystal oscillator is that its output is
A.
50Hz to 60Hz frequency
B. variable C. a
constant frequency
D. DC 116. The
lowest output impedance is obtained in case of BJT amplifiers for configuration B. CE configuration C. CC configuration D. CE with RE configuration A. CB
117. N-channel
FETs are superior to P-channel FETs, because have higher input impedance B. they have high switching time C. they consume less power D. mobility of electrons is greater than that of holes A. they
118. The
upper cutoff frequency of an RC coupled amplifier mainly depends upon capacitor B. emitter bypass capacitor C. output capacitance of signal source D. inter-electrode capacitance and stray shunt capacitance A. coupling
119. Just
as a voltage amplifier amplifies signal-voltage, a power amplifier power B. amplifies signal current C. merely converts the signal ac power into the dc power A. amplifies
D. merely
converts the dc power into useful ac power
120. A
radio frequency signal contains three frequency components, 870 KHz, 875 KHz and 880 KHz. The signal needs to be amplified. The amplifier used should be A. audio frequency amplifier B. wide band amplifier C. tuned voltage amplifier D. push-pull amplifier
121. An
oscillator of the LC type that has a split capacitor in the circuit is oscillator B. Colpitts oscillator C. Wien bridge oscillator A. Hartley
D.
R-C phase shift oscillator
122. The
function of a bleeder resistor in a power supply is same as that of load resistor B. to ensure a minimum current drain in the circuit C. to increase the output dc voltage D. to increase the output current A. the
123. In
a bistable multivibrator circuit, commutating capacitor is used
A.
to provide increaseac the base storage charge coupling
B. to C. to
D. to
increase the speed of response provide the speed of oscillations
124. n-type
silicon is obtained by with tetravalent element B. doping with pentavalent element C. doping with trivalent element D. doping with a mixture of trivalent and tetravalent element A. doping
125. In
the voltage range, Vp < VDS < BVDSS of an ideal JFE T or MOSFET drain current varies linearly with VDS. B. The drain current is constant. C. The drain current varies nonlinearly with VDS. D. The drain current is cut off. A. The
126.
In a voltage shunt negative feedback amplifier system, the input resistance Ri and the output resistance Ro of the basic amplifier are modified as follows: A. Ri is decreased and Ro increased B. both Ri and Ro are decreased C. both Ri and Ro are increased D. Ri is increased and Ro is decreased
127. The
use of crystal in a tunable oscillator frequency stability B. increases the gain of the oscillator A. improves
C. helps to obtain optimum output impedance D. facilitates generation of wide range of frequencies 128. The
large signal bandwidth of an operational amplifier is limited by its gain B. slew rate C. output impedance D. input frequency A. Loop
129. Rectification A. 51% B. 61% C. 71% D.
81%
efficiency of a full wave rectifier without filter is nearly equal to
130. When
the temperature of a doped semiconductor is increased, its conductivity
A. decreases B. increases C. does
not change or decreases depending on whether it is p or n type
D. increases 131. The
main characteristics of a Darlington Amplifier are
A.
highinput inputimpedance, impedance,low highoutput outputimpedance impedanceand andlow high current gain voltage gain input impedance, low output impedance and high current gain D. low input impedance, low output impedance and high current gain B. low
C. high
132. The
transconductance, gm, of a JFET is computed at constant VDS, by the following: / ΔVGS B. ΔVGS / ΔID C. ΔVGS x ΔID D. ΔID / ( VGS + ΔIDS) A. ΔID
133. The
feedback factor
at the frequency of oscillation of a Wien bridge oscillator is
A. 3 B. 1/3 C. 1/29 D.-3/29 134. In
an amplifier with negative feedback, the bandwidth is (where A = gain of the basic amplifier and = feedback factor) A. increased by a factor of B. decreased by a factor of ) C. increased by a factor of (1+A D. not affected at all by the feedback
135. The
‘slew rate’ of an operational amplifier indicates _______________ when a step input signal is given. A. how fast its output current can change B. how fast its output impedance can change C. how fast its output power can change D. how
fast its output voltage can change
136. In
a clamping circuit, the peak-to peak v oltage of the waveform being clamped is by the clamping B. not affected by the clamping C. determined by the clamping voltage value D. determined by the ratio of rms voltage of the waveform and the clamping voltage A. affected
137. Regulation
of a DC power supply is given by of no-load output voltage and full-load current B. ratio of full-load output voltage and full-load current C. change in output voltage from no-load to full-load D. change in output impedance from no-load to full-load A. product
138. A
‘literal’ in Boolean Algebra means
A.
a variable variable with in its its uncomplemented complement form only
B. a C. a
D. a
variable in its complemented form only variable in its complemented or uncomplemented form
139. In
an unclocked R-S flip-flop made of NOR gates, the forbidden input condition is = 0, S = 0 B. R = 1, S = 0 C. R = 0, S = 1 D. R = 1, S = 1 A. R
140. The
current amplification factor in CE configuration is
A. α B. β
+1 β
C. 1/ D. β 141. A
zener diode a high forward voltage rating B. has a sharp breakdown at low reverse voltage C. is useful as an amplifier D. has a negative resistance A. has
142. The
maximum possible collector circuit efficiency of an ideal class A power amplifier is
A. 15% B. 25% C. 50% D. 75% 143. Negative
feedback in an amplifier the voltage gain B. Increases the voltage gain C. Does not affect the voltage gain D. Converts the amplifier into an oscillator A. Reduces
144. For
generating 1 kHz signal, the most suitable circuit is oscillator B. Hartley oscillator C. Tuned collector oscillator D. Wien bridge oscillator A. Colpitts
145. The
output stage of an op-amp is usually a emitter follower B. transformer coupled class B amplifier C. Class A power amplifier D. Class B amplifier A. complementary
146. When
a sinusoidal voltage wave is fed to a Schmitt trigger, the output will be
A.
triangular wave square wave
B. asymmetric C. rectangular D. trapezoidal 147. The
wave wave
logic gate which detects equality of two bits is
A. EX-OR B. EX-NOR C. NOR D. NAND 148. The
overall bandwidth of two identical voltage amplifiers connected in cascade will the same as that of a single stage B. be worse than that of a single stage C. be better than that of a single stage D. be better if stage gain is low and worse if stage gain is high A. remain
149. Field
effect transistor has input impedance B. large output impedance C. large power gain D. large votage gain A. large
150.
Which of the following parameters is used for distinguishing between a small signal and a large signal amplifier? A. voltage gain B. frequency response C. harmonic Distortion D. input/output impedances
151.
Which of the following parameters is used for distinguishing between a small signal and a large signal amplifier? A. instability B. bandwidth C. overall gain D. distortion
152.
If the feedback signal is returned to the input in series with the applied voltage, the input impedance ______. A. decreases B. increases C. does not change D. becomes infinity
153.
Most of linear ICs are based on th e two transistor differential amplifier because of its A. input voltage dependent linear transfer characteristic B. high voltage gain C. high input resistance D. high CMRR 154. The
waveform of the output voltage for the circuit shown in Fig.1 (RC >> 1) is a
A. sinusoidal wave B. square
wave of spikes D. triangular wave C. series
155.
A single phase diode bridge rectifier supplies a highly inductive load. The load current can be assumed to be ripple free. The ac supply side current waveform will be A. sinusoidal B. constant DC C. square D. triangular
156. Conductance
of any conductor is expressed as
A. ampere/watt B. mho 2
C. volt
/watt 2
D. watt/ampere 157. The
“Superposition theorem” is essentially based on the concept of
A. duality B. linearity C. reciprocity D. non-linearity 158. Cells
are connected in parallel in order to the voltage available B. reduce cost of wiring C. increase the current available D. reduce the time required to fully charge them after use A. increase
159. The
power factor of a purely resistive circuit is
A. zero B. unity C. lagging D. leading 160. The
power taken by a three phase load is given by the expression
A.
3 VLrt. IL of cos3 V I cos L L C. 3 VL IL sin θ D. sq. rt. of 3 V L IL sin θ B. sq.
161. Which
of the following generating stations has the minimum running cost? station B. nuclear power station C. thermal power station D. diesel power plant A. hydro-electric
162. Which
of the following motors has a high starting torque? series motor B. dc series motor C. induction motor D. synchronous motor A. ac
163. A
step-up transformer increases
A. voltage B. current C. power D. frequency 164. The
effect of increasing the length of the air gap in an induction motor will be to increase factor B. speed C. magnetizing current A. power
D. air-gap
flux
165. The
combined resistance of two equal resistors connected in parallel is equal to half the resistance of one resistor B. twice the resistance of one resistor C. four times the resistance of one resistor D. one fourth the resistance of one resistor A. one
166. The
Q- factor of a coil is given by power factor cosine j B. ratio of maximum energy stored & energy dissipated per cycle C. reciprocal of its power factor D. ratio R/Z A. its
167. Voltage
equation of a dc motor is = Eb + IaRa B. Eb = V + I aRa C. V = Eb / I aRa 2 D. V = Eb + Ia Ra A. V
168. The
efficiency of a transformer is maximum when
A.
it runs runs at at full halfload full load
B. it
C. its D. it
Cu loss equals iron loss runs overload
169. The
crawling in an induction motor is caused by design of the machine B. low voltage supply C. high loads D. harmonics developed in the motor A. improper
170. The
starting winding of a single-phase motor is placed in
A. rotor B. stator C. armature D. field 171. Reduction
in the capacitance of a capacitor- start motor results in reduced
A. noise B. speed C. starting
torque reaction
D. armature 172. In
an AC circuit, the ratio of kW / kVA represents factor B. load factor C. form factor A. power
D. diversity 173. The
factor
unit of inductance is
A. ohm B. mho C. farad D. henry 174. Thevenin’s equivalent circuit consists
of _________. combination of RTh, ETh and RL B. series combination of RTh, ETh C. parallel combination of RTh, ETh D. parallel combination of RTh, ETh and R L A. series
175. In
an RLC circuit, the phase of the current with respect to the circuit voltage will be_________.
A. leading B. same C. lagging D. depends 176. The
upon the value of L and C
frequency of D C supply is__________.
A.
zero Hz Hz D. 100 Hz B. 16 C. 50
177. Load
factor is defined as the ratio of _________. Demand / Max. Demand B. Max. Demand / Average Demand C. Average Demand / Connected load D. Connected load / Max. Demand A. Average
178. Static Capacitors
are used for__________. improvement B. current improvement C. voltage improvement D. power factor improvement A. power
179. The
speed of an induction motor__________. too much with the increase of load B. increases with the increase of load C. decreases slightly with the increase of load D. remains constant with the increase of load A. decreases
180. Centrifugal
switch is provided for disconnecting the auxiliary winding in a_______. start motor B. capacitor run motor C. reluctance motor A. capacitor-
D. hysteresis
motor
181. Rotating
magnetic field is produced in a ________. phase induction motor B. three- phase induction motor C. DC series motor D. AC series motor A. single-
182. The
frequency of the secondary voltage of a transformer will be_________. than the frequency of the primary voltage B. equal to the primary voltage C. greater than the frequency of the primary voltage D. very much greater than the frequency of the primary voltage A. less
183. The
demand factor for the electrical system is the ratio of demand to connected load B. maximum demand to average load C. average power to maximum power D. relative power to total power A. maximum
184. When
a low resistance is connected in parallel with a high resistance, the combined resistance is
A.
always less more than the high resistance than the low resistance
B. always C. always D. either 185. A
between the high resistance & low resistance lower or higher than low resistance depending on the value of high resistance
DC series motor is best suited for driving
A. lathes B. cranes
and hoists and punches D. machine tools C. shears
186. Transformer
cores are built up from laminations rather than from solid metal so that penetrates the core more easily B. eddy current loss is reduced C. less lamination is required for the windings D. turn ratio is higher than voltage ratio A. oil
187. In
a DC series motor increase in load current results in in speed B. increase in speed C. better commutation D. increase in the back EMF A. decrease
188. The
starting torque of a single phase induction motor is
A. high B. moderate C. low D. zero 189.
An electric motor in which rotor and stator fields rotate simultaneously is called a __________ motor. A. DC B. induction C. synchronous D. universal
190. In
ac circuit the product of voltage and current is known as
A. power B. real
power power
C. resistive D.
apparent power
191. A
network that does not have either voltage or current sources is called network B. passive network C. resistive network D. dummy network A. active
192. The
power factor at resonance in RLC circuit is
A.
zero
B. unity C. 0.5 D. 0.5
lagging leading
193. Transformer
core is laminated to the copper losses B. reduce the core losses C. reduce the eddy current losses D. none of these A. reduce
194. Star
– delta starter of an induction motor resistance in rotor circuit B. inserts resistance in stator circuit C. applies reduced voltage to rotor D. applies reduced voltage to stator A. inserts
195. Stator
core of an induction motor is made of cast iron B. mild steel C. silicon steel stampings D. soft wood A. laminated
196. Watt
hour is the unit of power B. electric capacity C. electric energy A. electric
D. electric
charge
197. A
battery is a source of voltage B. single phase AC voltage C. three phase AC voltage D. AC or DC voltage A. DC
198. Which
DC motors has approximately constant speed? motor B. shunt motor C. cumulatively compound motor D. all of the above A. series
199. Resistance
of a wire is r ohms. The wire is stretched to double its length, then its resistance in ohms
is A. r/2 B. 4r C. 2r D. r/4 200.
An electric machine will have high efficiency when A. input/output ratio is low B. reactive
power is more consumption is low D. losses are low C. kWh
201. Which
type of loss is not common to transformers and rotating machines? current loss B. copper loss C. hysteresis loss D. windage loss A. eddy
202.
The difference between the synchronous speed and the actual speed of an induction motor is known as A. regulation B. back lash C. slip D. lag
203.
In two wattmeter method of power measurement, if one of the wattmeter shows zero reading, then it can be concluded that A. power factor is unity B. power factor is zero C. power factor is 0.5 lagging D. power factor is 0.5 leading
204. Which
of the following will remain the same in all parts of a series circuit?
A. voltage B. current C. power D. resistance 205. Which
single phase motor would you select for a tape recorder? motor B. hysteresis motor C. synchronous motor D. universal motor A. reluctance
206. Under
the condition of resonance, RLC series circuit behaves as a, resistive circuit B. purely inductive circuit C. capacitive circuit D. reactive circuit A. purely
207. During
charging, the electrolyte of a lead acid cell becomes
A.
stronger
B. weaker C. water D. dilute 208. As
compared to shunt and compound motors, series motor have the highest torque because of its comparatively __________ at the start. A. lower armature resistance B. stronger series field C. fewer series turns D. larger armature current
209. The
voltage ratio of the transformer is given as / EP B. TS / TP C. TP / TS D. EP / TS A. ES
210. The
relationship between the frequency of ac wave and the time period is given by =T 2 B. f = 1 / T C. f = 1 / T 2 D. f = T A. f
211. Which
of the following power plant has the maximum efficiency?
A. thermal B. hydroelectric C. nuclear D. diesel 212. Which
of the following components are all active components? resistor and an inductor B. a diode, a BJT and an FET C. a capacitor, and an inductor D. an operational amplifier, a BJT and thermionic triode A. a
213. In
forward mode NPN BJT, if we increase the voltage VCC, the collector current increases to ohm’s law, higher VCC causes higher current B. due to base width decrease less carrier recombines in the base region C. as the gradient of the minority carriers in the base region becomes steeper A. due
D.
B
due to both the reasons
C
and
214. The
barrier voltage (Vr or Vo) in a junction diode is the effect of p-side and n-side of the junction forming a battery the emf required to move the holes fast enough to have the mobility equal to that of the electrons the recombination of charge carriers across the junction leaving behind the opposite charged ions
A. the B.
C.
D.
the voltage needed to make the semiconductor material behave as a conductor 215. An
emitter follower has high input impedance because emitter resistance is used B. large biasing resistance is used C. there is negative feedback in the base emitter circuit D. the emitter-base junction is highly reverse biased A. large
216. In
a differential amplifier an ideal CMRR is
A. infinity B. zero C. –1 D. +1 217. FET
is advantageous in comparison with BJT because of input impedance B. high gain-bandwidth product C. its current controlled behavior D. high noise immunity A. high
218. The
emission of electrons in a vacuum diode is achieved by field B. magnetic field C. heating D. electron bombardment A. electrostatic
219. The
color code of a resistor of nominal value 2.7K
± 10% is
A. red, violet, red and silver B. red, violet, yellow and gold C. red, D. red,
violet, orange and silver violet, red and gold
220. Capacitor
that can have the highest capacitance value is
A. mica B. paper C. electrolytic D. ceramic
221.
The equivalent current-source representation for a voltage-source with open circuit voltage 12 V and internal resistance 3 ohms is A. a current-source of strength 4A in shunt with a resistance of 6 B. a current –source of strength 4A in series with a resistance of 3 C. a current-source of strength 4A in shunt with a resistance of 3 ohms D. a current-source of strength 4A in shunt with a resistance of 36 ohms
222.
An intrinsic semiconductor at absolute zero temperature A. has a large number of holes B. behaves
like an insulator like a metallic conductor D. has few holes and same number of electrons C. behaves
223. For
the operation of a depletion-type N-MOSFET, the gate voltage has to be positive B. high positive C. high negative D. zero A. low
224. The
typical operating voltage for LED’s ranges from V to 0.6 V B. 6 V to 10 V C. 1.5 V to 2.5 V D. 9 V to 10 V A. 0.2
225. Capacitors
for integrated circuits be made using diffusion techniques B. can be made with very high values of capacitance C. are always discrete components connected externally D. can be made using silicon dioxide as the dielectric A. cannot
226. Which
one of the following statements is not true? is a measure of a capacitor’s capability to store charge. B. a capacitor offers high impedance to ac but very low impedance to dc. A. capacitance
C. a capacitor is also used as bypass capacitor. D. capacitors are used to couple alternating voltages
from one circuit to another and at the same time to block dc voltage from reaching the next circuit.
227. In
a Zener diode large reverse current is due to
A. collision B. presence
of impurities of bonds D. lower resistance in reverse biased region C. rupture
228. JFET
has main drawback of low input impedance B. having high output impedance C. being noisy D. having small gain-bandwidth product A. having
229. A
UJT has
A.
stable negative resistance characteristics firing current as a waveform generator D. all of the above B. low C. use
230. For
thermionic emission material with high work function is preferable B. a material with low work function is preferable C. the work function of the material has no importance D. none of these is true A. a
231. Ideal
operational amplifier has input impedance of
A. 1MW B. infinity C. zero D. 1Ω 232.
The CE configuration amplifier circuits are preferred over CB configuration amplifier circuits because they have A. lower amplification factor B. larger amplification factor C. high input resistance and low output resistance D. none of these
233. The
most commonly used type of electron emission in electron tubes is emission B. thermionic emission A. photo-electron
C. field emission D. secondary emission 234. A
device whose characteristics are very close to that of an ideal current source is gas diode B. a BJT in CB mode C. a BJT in CE mode D. a triode A. a
235. In
an N-type semiconductor, the concentration of minority carriers mainly depends upon doping technique B. the number of donor atoms C. the temperature of the material A. the
D.
the quality of the intrinsic material, Ge or Si
236. When
forward bias is applied to a junction diode, it the potential barrier B. decreases the potential barrier C. reduces the majority-carrier current to zero D. reduces the minority-carrier current to zero A. increases
237.
The theoretical maximum efficiency of a Bridge rectifier circuit is A. 48.2% B. 81.2% C. 82% D. 40.6% 238. A
switching voltage regulator can be of the following type:
A. step-down B. step-up C. inverting D. none
of these
239. A
UJT contains pn junctions B. three pn junctions C. two pn junctions D. one pn junction A. four
240. The
foundation on which an IC is built is called insulator B. a base C. a wafer D. a plate A. an
241. X-ray
tubes make use of emission B. secondary emission A. thermionic
C. high field emission D. photoelectric emission 242. Which
of the following components are all active components? resistor and a capacitor B. a microphone, a LCD and a Thyratron C. an electric bulb, a transformer and a varactor diode D. an SCR, a vacuum diode and an LED A. a
243. Doping
materials are called impurities because they the number of charge carriers B. change the chemical properties of semiconductors C. make semiconductors less than 100 percent pure A. decrease
D.
alter the crystal structures of the pure semiconductors
244. Avalanche
breakdown is primarily dependent on the phenomenon of
A. collision B. doping C. ionization D. recombination 245. In
a rectifier, larger the value of shunt capacitor filter
A.
larger the the peak peak-to-peak value of ripple voltage current in the rectifying diode
B. larger
C. longer
the time that current pulse flows through the diode the dc voltage across the load
D. smaller 246. The
main reason why electrons can tunnel through a P-N junction is that have high energy B. barrier potential is very low C. depletion layer is extremely thin D. impurity level is low A. they
247. If
a change in base current does not change the collector current, the transistor amplifier is said to be A. Saturated B. Cut-off C. Critical D. Complemented
248. The
extremely high input impedance of a MOSFET is primarily due to the of its channel B. negative gate-source voltage C. depletion of current carriers D. extremely small leakage current of its gate capacitor A. absence
249. After
firing an SCR, the gating pulse is removed. The current in the SCR will the same B. immediately fall to zero A. remains
C. rise up D. rise a little 250. In
and then fall to zero
the context of IC fabrication, metallization means metallic wires B. forming interconnecting conduction pattern and bonding pads C. depositing Sio2 layer D. covering with a metallic cap A. connecting
