1.

A moving coil galvanometer has a resistance of 5 ohm and gives full scale deflection
when carrying 50 milli amperes. The instrument can be used to measure 100 volt by
connecting in series with the instrument a resistance of
(A) 1000 ohm .
(B) 2000 ohm
(C) 1995 ohm
(D) 5000 ohm
2. Rectifier moving coil instruments respond to
(A) peak value, irrespective of the nature of the waveform.
(B) average value, for all waveforms.
(C) mms value for all waveforms.
(D) rms value for symmetrical square waveforms.
3 3. If two spheres of radii R 1 and R2 (R1>R2) are connected by a conducting wire and
each of the spheres has a charge q, which of the following statement is then true?
(A) Sphere of radius R, will have zero potential.
(B) Sphere of radius r, will have greater potential.
(C) Sphere of radius R, will have less potential.
(D) Potentials of both the spheres will be equal.
4. Consider a single crystal of an intrinsic semiconductor. The number of free carriers at
the Fermi level at room temperature is
(A) half the total number of electrons in the crystal.
(B) half the number of free electrons in the crystal.
(C) half the number of atoms in the crystal.
(D) zero.
5. Which of the following loads is not responsible for low power factor?
(A) Arc lamps
(B) Incandescent lamp
(C) Fluorescent tubes .
(D) Induction motors
6. Swamping resistance is used to compensate error due to
(A) stray magnetic field.
(B) temperature variations.
(C) large supply variations.
(D) None of the above
7. Shunt conductance in power transmission is due to
(A) leakage over the poles.
(B) leakage over the insulators.
(C) leakage over the conductors.
(D) leakage between ground and conductors.
8. Two long parallel conductors carry 100A. If the conductors are separated by 20ınm,
the force per metre of length of each conductor will be
(A) 0.1N
(B) 1N
(C) 10N
(D) 100N
9. In a three-phase half-wave rectifier if the input phase voltage is 2001, the PIV required
for each diode will be
(A) 400V
(B) 346V
(C) 370V.
(D) 200V
10. A 150V moving iron voltmeter of accuracy class 1.0 reads 75V when used in a circuit
under standard conditions. The maximum possible percentage error in the reading is
(A) 0:5
(B) 1:0
(C) 2.0
(D) 4.0
11. A diode having breakdown voltage of greater than 5V and a +ve temperature
coefficient is
(A) Zener diode
(B) Avalanche diode
(C) Tunnel diode
(D) P-N junction diode
12. The bandwidth of a feedback amplifier
(A) remains unaffected.
(B) increases by the same amount as the gain decreases.
(C) decreases by the same amount as the gain decreases.
(D) decreases by the same amount as the gain increases.
13. A PMMC type ammeter and a moving iron type ammeter are connected in series in a
resistive circuit fed from output of a half wave rectifier voltage source. If the moving iron
type reads 5A, the PMMC type instrument is likely to read
(A) Zero
(B) 2:5 A
(C) 3.18A
(D) 5A
14. Two identical stages of amplifiers are cascaded in R-C coupling. If 10 is the mid band
voltage gain of each stage, then the overall gain of cascade configuration will be
(A) 40 dB
(B) 20 dB
(C) 100 dB
(D) 20 log20dB
15. A Wheatstone bridge requires a change of 6 ohm in the unknown arm of the bridge to
produce a change in deflection of 3mm of the galvanometer. The sensitivity of the
instrument is
(A) 1.5%
(B) 2%
(C) 0.5%
(D) 2-5%
16. The effects of power factor and frequency variations in wattmeter can be reduced if
(A) pressure coil induction is zero.
(B) a capacitance is connected in parallel to pressure coil.
(C) damping is not provided.
(D) voltage coil resistance is zero.
17. Total inductance of a group of two series connected and unshielded inductance when
flux produced by one opposes the flux produced by the other is equal to i
(A) L+L,
(B) 2M
(C) L,+L+2M
(D). L,+L2-2M
18. In a microprocessor, the address of the next instruction to next executed, is sorted in
(A) Stack pointer
(B) Address latch
(C) Program counter
(D) General purpose register
19. Corona loss increases when the density of air
(A) increased.
(B) decreased.
(C) remains uniform.
(D) is uniform.
20. Which relay is used in protection of long transmission lines?
(A) Mho relay
(B) Reactance relay
(C) Impedance relay
(D) None of the above
21. Insulation resistance of high voltage circuit breakers is more than
(A) IM ohm
(B) 20M ohm
(C) 100M ohm
(D) 500M ohm
22. An average emf of 10V is induced in a 100 turn solenoid as the result of a change in
flux which occurs in 0-5 second. The total flux change is
(A) 0-05 Wb
(B) 0-5 Wb
(C) 5 Wb
(D) 50 Wb
23. Scottky barrier diode can be used as
(A) low noise amplifier.
(B) variable capacitance device
(C) power supply rectifier.
(D) low level detector.
24. A conductor 0-2 m long carries a current of 3 amperes at right angle to a magnetic
field of O-5 tesla. The force acting on the conductor will be
(A) 0:3N
(B) 1.0N
(C) 3.0N
(D) 30 N
25. When the power is to be transmitted over a distance of 300km, the transmission
voltage should be in the range of
(A) 33kV
(B) 66kV
(C) 132kV
(D) 220/400kV
26. Two infinitely long parallel conductors in vacuum and separated 1 metre between
centres when a current of 1 ampere flows through each conductor, produce on each
other a force
(A) 2 x 10-7N/m
(B) 2 x 10 N/m
(C) 2 x 10-N/m
(D) 2 x 10-2N/m
27. In a shunt generator the voltage builds up till constrained by
(A) saturation of iron.
(B) speed limitation.
(C) armature' heating.
(D) insulation restrictions.
28. In Ward Leonard control change in speed of motor can be obtained by varying
(A) supply voltage of the dc motor.
(B) field excitation of dc motor.
(C) armature voltage of dc motor.
(D) armature current of dc motor.
29. In a highly capacitive circuit the
(A) actual power is more than its reactive power.
(B) reactive power is more than the actual power.
(C) reactive power is more than the apparent power.
(D) apparent power is equal to the actual power.
30. In a series circuit on resonance, following will occur:
(A) X=Xc
(B) V, =VC
(C) Z=R and V = V.
{D) All of the above
31. The surface integral of electric field intensity gives
(A) net flux imanating out from the surface.
(B) net charge enclosed by the surface.
(C) flux density.
(D) None of the above
32. A conductor of axial length 30cm carries a current of 100A and lies at right angles to
a magnetic field of strength 0.4 Tesla. What is the force in newtons exerted on it?
(A) 10 N
(B) 12 N
(C) 1.2N
(D) ON
33. Which of the following waves has unity form factor?
(A) Triangular wave
(B) Square wave
(C) Sine wave
(D) None of the above
34. Compensating windings are used in DC generators
(A) to provide path for the circulation of cooling air,
(B) to neutralise the cross magnetising effect of the armature reaction.
(C) mainly to reduce the eddy currents by providing local short circuits.
(D) None of the above
35. A solenoid produces a flux of 12m Wb and a flux density of 0.9 tesla. The inside
diameter of the solenoid must be
(A) 5 cm
(B) 10 cm
(C) 13 cm
(D) 130 cm
36. A 2004H coil has Q of 250 at resonance frequency of 800kHz. The effective resistance
of coil is
(A) 8 ohm
(B) 4 ohm .
(C) 2 ohm
(D) 1 ohm
37. In a parallel R-C circuit, the supply current always ___ the applied voltage.
(A) leads
(B) lags ·
(C) remains in phase with :
(D) None of the above
38. What is the rms value of rectangular voltage wave with amplitude of 100V?
(A) 50√ 2V .
(B) 100V
(C) 110V
(D) (100/√ 2)V
39. The inductance of a coil can be increased by
(A) choosing core material having high relative permeability. .
(B) increasing core length.
(C) decreasing the number of turns.
(D) decreasing the diameter of the factor.
40. The peak factor of a triangular ac voltage wave is
(A) 1
(B) 1:11
(C) 1:41
(D) 1.732
41. In Hopkinson's test for dc motors
(A) speeds of the motors are separately controlled.
(B) both motors are run as generators.
(C) both machines are mechanically coupled.
(D) both motors run at their respective rated speeds.
42. Pure inductive circuit takes power from the ac line when
(A) applied voltage increases but current decreases.
(B) applied voltage decreases but current increases.
(C) both applied voltage and current rise.
(D) both applied voltage and current decrease.
43. If the voltage at a dc shunt motor terminal is halved, load torque being the armature
current will be
(A) Halved
(B) Doubled
(C) Unaltered
(D) Zero
44. In a pure inductive circuit if the supply frequency is reduced to half, the current will
be
(A) reduced to one fourth.
(B) reduced by half. ..
(C) doubled.
(D) four times at high.
45. The electric field intensity of an equipotential surface is.
(A) always perpendicular to the surface.
(B) always parallel to the surface.
(C) zero...
(D) None of the above .
46. Which of the following DC generator can build up without any residual magnetism in
the poles?
(A) Compound generator
(B) Self-excited generator
(C) Series generator
(D) Shunt generator
47. The negative maximum value of a cosine wave form occurs at
(A) 270 degree
(B) 180 degree
(C) 90 degree
(D) O degree
48. The load current of a dc series motor is 50A, when supplying a 'full load torque. If the
current is reduced to 25A, the torque will be
(A) 25% of full load torque.
(B) 50% of full load torque.
(C) 150% of full load torque.
(D) same as full load torque.
49. Which of the following frequencies has the longest time period?
(A) 1 Hz
(B) 1 kHz
(C) 10 Hz
(D) 10 kHz
50. for copper is lower as compared to aluminium
(A) Resistivity
(B) Specific Gravity
(C) Melting Point
(D) All of the above
51. If copper loss of a transformer at 1/4th full load · is 100W, then its full load copper
loss would be
(A) 100W
(B) 400W
(C) 800W
(D) 1600W
52. In an interconnected power system the increase in the field current in any generating
unit causes
(A) increase in active power flow from the unit to rest of the system.
(B) increase in reactive power flow from the unit to the rest of the system.
(C) decrease in active power and increase in reactive power flow from the unit. .
(D) increase in both active and reactive power flow from the unit.
53. A 66 kV system has string insulator having five discs and the earth to disc
capacitance ratio of 0.10. The string efficiency will be
(A) 89%
(B) 75%
(C) 67%
(D) 55%
54. A differentially compounded dc motor runs at a full load speed of 480 rpm. If the
series field of a differentially wound compound dc motor is short circuited, then the
speed will be
(A) less than full load speed.
(B) more than full load speed.
(C) same to full load speed.
(D) zero.
55. In a power station, the cost of generation of power reduces most effectively when
(A) diversity factor alone increases.
(B) both diversity factor and load factor increase.
(C) load factor alone increases.
(D) both diversity factor and load factor decrease.
56. Bio-gas plants are suitable for
(A) Metallurgical industries
(B) Commercial complexes
(C) Rural areas
(D) Coal mines
57. The presence of earth in case of overhead lines
(A) increases the capacitance.
(B) increases the inductance.
(C) decreases the capacitance.
(D) decreases the inductance.
58. Low tension cables and high tension cables can be used respectively for voltage
below
(A) 33kV and 66kV
(B) 11kV and 33kV
(C) IkV and 11kV
(D) 400V and 1000V
59. The ratio of puncture voltage to the flashover voltage of a line insulator is
(A) equal to 1.
(B) lower than 1.
(C) much greater than 1.
(D) None of the above
60. A dc series motor develops a torque of 10 Nm at 1A of load current. If the current is
increased to 2A, the torque developed will be
(A) 80 Nm
(B) 40 Nm
(C) 20 Nm
(D) 10 Nm
61. Increase in frequency of transmission line causes
(A) no change in line resistance.
(B) increase in line resistance.
(C) decrease in line resistance.
(D) decrease in line series resistance.
62. A shunt generator running at 1000 rpm has generated emf as 100V. If the speed
increases to 1200 rpm, the generated emf will be nearly
(A) 120V
(B) 140V
(C) 175V
(D) 240V
63. A 10 ohm load is connected to the secondary of a Single phase 3300110V power
transformer. The effective load on the 3.3 kV bus bar is nearly
(A) 0.9 K ohm
(B) 9 K ohm
(C) 10 K ohm
(D) 0 .300 K ohm
64. Corona loss can be reduced by the use of hollow conductors because
(A) the current density is reduced.
(B) the eddy current in the conductor is eliminated.
(C) for a given cross-section the radius of the conductor is increased.
(D) of better ventilation in the conductor.
65. In a cable of conductor diameter d and overall diameter with dielectric material D the
maximum dielectric stress
(A) occurs at the conductor surface and is proportional to d.
(B) occurs at the conductor surface and is proportional to 1/d.
(C) occurs at the middle of the dielectric and is proportional to 1/D..
(D) occurs at the outer surface of the dielectric .. . and is proportional to D.
66. A gas turbine works on
(A) Carnot cycle
(B) Brayton cycle
(C) Dual cycle
(D) Rankine cycle
67. To meet the reactive power requirements load centres usually
(A) shunt capacitors are used.
(B) series capacitors are used.
(C) tap changing transformers are used.
(D) shunt reactors are used.
68. The voltage of a bus can be controlled by controlling the
(A) phase angle.
(B) reactive power of the bus.
(C) active power of the bus.
(D) phase angle and the reactive power.
69. Cross-section of the iron core of a power transformer is approximately circular. This is
done because
(A) it is easy to prepare circular coils.
(B) it is easy to assemble circular iron core.
(C) electromagnetic forces tend to make the coil circular.
(D) All of the above
70. A generating station which has a high investment cost and low operating cost is
usually operated as a
(A) peak load station.
(B) base load station.
(C) medium load station.
(D) None of the above
71. Sulphur hexafluoride cable is insulated by
(A) Impregnated paper
(B) Polyvinyl chloride
(C) High pressure oil
(D) Compressed gas
72. If the frequency of a transmission system is changed from 50Hz to 100Hz, the string
efficiency
(A) will increase.
(B) will decrease.
(C) remain unchanged.
(D) may increase or decrease depending on line parameters.
73. Sumpner's test is carried out
(A) mainly to find out the temperature rise on full load economically.
(B) mainly to find out efficiency of the transformer.
(C) mainly to find out regulation of the transformer.
(D) Due to none of the above reasons
74. When an alternator is delivering a balanced load at unity power factor the phase
angle (in degree) between line voltage and line current is
(A) 90
(B) 60
(C) 30
(D) O
75. In a dc motor the developed torque is 200. N-m at 600 rpm. At 500 rpm the motor
torque would be
(A) 133 N-m
(B) 167 N-m
(C) 180 N-m
(D) 200 N-m
76. Two heaters rated at 1000W, 250V each are connected in series across a 250V 50Hz
AC mains. The total power drawn from the supply would______________ W.
(A) 1000
(B) 500
(C) 250 .
(D) 2000
77. Two transformers operating in parallel will share the load depending upon their
(A) efficiency
(B) rating
(C) per unit impedance
(D) leakage reactance
78. Two capacitors each of breakdown voltage 25 V are combined in series. The
breakdown voltage of the combination will be
(A) 25V
(B) 25√ 2V
(C) 125√ 2v
(D) 50v
79. One metre copper wire is cut into 10 equal parts. These are then connected in
parallel. The total resistance of this parallel combination will be k times the resistance of
original uncut wire where value of k is
(A) 1
(B) 0.1
(C) 0.01
(D) 10
80. Reduced voltage starting can be used with
(A) slip ring induction motor only but not with squirrel cage induction motor.
(B) squirrel cage induction motor only but not with slip ring motor.
(C) squirrel cage as well as slip ring induction motor.
(D) None of the above two motors
81. A wire of resistance 20 ohm is drawn so that its diameter becomes one fifth. Its
resistance will now be
(A) 10 ohm
(B) 25 ohm
(C) 50 ohm
(D) 500 ohm.
82. When the voltage and frequency of a three phase induction motor is halved,
(A) air gap flux is halved.
(B) slip at rated torque increases greatly.
(C) the maximum torque is halved.
(D) the maximum torque remains the same.
83. Effect of reducing the frequency of ac supply with corresponding reduction in applied
voltage on the three phase induction motor
(A) has no effect on the magnitude of starting current.
(B) is to reduce magnitude of starting current.
(C) is to increase the magnitude of starting current.
(D) All of the above
84. If the length of the transmission line is increased its capacitance will
(A) increase
(B) decrease
(C) remain same :
(D) None of the above
85. For the same electrical resistance, the weight aluminium conductor as compared to
copper conducto of identical cross section is
(A) 25%
(B) 50%
(C) 65%
(D) 100%
86. For coherent machines the equivalent inertia constant(H) is given by
(A) H1H2
(B) H1-H2
(C) H1+H2,
(D) H1/H2
87. Assuming carrier mobility to be temperature independent it can be shown that pure
silicon(Ex=0.7eV) have the same conductivity at a temperature of
(A) 191 K
(B) 300 K
(C) 471 K
(D) 1470 K
88. The ratio of resistances of a 100W, 220V lamp to that of a 100W, 110V lamp will be at
the respective
voltages
(A) 4
(B) 2
(C)1/2
(D) 1/4
89. When the line voltage of an induction motor is reduced to 75% of its rated value, its
starting current is reduced by
(A) 25%
(B) 75%
(C) 86-6%
(D) 100%
90. Charging current in the transmission line
(A) increases the line losses.
(B) decreases the line losses.
(C) will not affect the line losses.
(D) None of the above
91. A hollow insulated conducting sphere is given a positive charge of 90uC. What will be
the electric field at the centre of the sphere if its radius is 1 metre?
(A) Zero
(B)
(C)
(D)
92. Capacitance between two conductors of a three phase line being 2uF, the
capacitance of each conductor to neutral becomes
(A) 3uF
(B) 6uF
(C) 9uF
(D) 12uF
93. The pull out torque for a normal squirrel cage induction motor usually occurs at a
percentage slip of above
(A) 5 to 10%
(B) 20 to 25%
(C) 30 to 40%
(D) 40 to 50%
94. A potential of 400V is applied to a parallel plate capacitor, plates are at 2 mm apart.
The strength of electric field in kVm is
(A) 0.20
(B) 2.0
(C) 20.
(D) 200
95. Rotor bars of squirrel cage rotor are sometimes skewed
(A) to prevent rotor from aligning and locking up with stator.
(B) to give more uniform torque.
(C) to reduce humming noise.
(D) due to all above reasons
96. The most economic voltage for transmitting power over a distance by transmission
lines is approximately
(A) 0.6kV/km
(B) 1.6kV/km
(C) 2.6kV/km
(D) 3.6kV/km
97. When single phasing occurs in a three phase induction motor under running
conditions, it
(A) will stall.
(B) will become noisy while it still runs.
(C) will keep running through with slightly increased slip.
(D) may either stall or continue depending on the load carried by it.
98. A piece of copper and another germanium are cooled from room temperature to 80K.
The resistance of
(A) each of them increases.
(B) each of them decreases.
(C) copper increases and germanium decreases.
(D) copper decreases and germanium increases.
99. The amount of leakage flux in the transformer windings depends upon
(A) the mutual flux.
(B) turn ratio.
(C) the load connected.
(D) the applied voltage.
100. If a 5W, 230V lamp is in series with a 100W, 250V lamp and the combination is
connected across a 230V supply, the bulb that will not glow is
(A) 100W, 230V
(B) 5W, 230V
(C) Any of the two .
(D) Not a single bulb will glow