1. The best suitable material for the heating element is

Tungsten

Nichrome

Manganin

Carbon

2. Pure silicon is

a p-type semiconductor

an n-type semiconductor

an intrinsic semiconductor

an extrinsic semiconductor

3. Impurity atoms to be added to pure silicon in order to make a p-type semiconductor belongs to

Phosphorous

Boron

Antimony

Aluminium

4. Resistivity of a wire depends upon

Material

Area

Length

All of these

5. If a ferromagnetic material is heated up to Curie temperature, it becomes

Permanent magnet

Anti-ferromagnetic material

Diamagnetic material

Paramagnetic material

6. At absolute zero temperature, an intrinsic semiconductor behaves as

a good conductor

a super conductor

an insulator

variable resistor

7. In an intrinsic semiconductor the Fermi level is

closer to valence band.

closer to conduction band.

within the balance band.

midway between the valence and conduction bands.

8. The reluctance offered by a magnetic material is highest when it is

Diamagnetic

Paramagnetic

Ferromagnetic

None of these

9. If temperature of a pure silicon specimen is increased, then

only number of free electrons increase.

only number of free holes increase.

number of free holes and free electrons increases.

only number of free holes decrease.

10. Varnishes protect the insulating materials against

dust and oil

moisture, dirt and oil

moisture and fire hazards

None of the above

11. If a 220 V heater is used on 110 V supply, the heat produced by it will be nearly

one half

twice

one-fourth

four times

12. Two sinusoidal currents are given by following equations

<img src='./qimages/3399-12.jpg'>

The phase difference between them is

105°

75°

15°

60°

13. The reactance offered by a capacitor to an alternating current of frequency 50 Hz is 10 ohm. If frequency is increased to 100 Hz, the reactance will be

2.5 ohm

5.0 ohm

20.0 ohm

40.0 ohm

14. The r.m.s. value of a half-wave rectified alternating current is 10 A. Its value for full-wave rectification will be 20

20/pie A

40/pie A

20/ route 2 A

20 A

15. In the following figure, the resistance measured across A and B will be

<img src='./qimages/3399-15.jpg'>

16. In the following figure, the voltage across C1 will be

<img src='./qimages/3399-16.jpg'>

100V

200V

150V

300V
17. An alternating current given by i 14.14 sin has an r.m.s. value of

1.96 A

7.07 A

10.0 A

14.14 A
18. In the following figure, resistor R2 becomes open circuited, the reading of voltmeter will be

<img src='./qimages/3399-18.jpg'>

zero

50 V

150 V

200 V


19. The capacity of a battery is measured in

Watts

Watt-hours

Amperes

Ampere-hours

20. If both the number of turns and core length of an inductive coil are doubled, then its self inductance will be

halved

doubled

quadrupled

unaffected

21. Mutual inductance between two magnetically coupled coils depends on

number of turns only

permeability of the core only

cross-sectional area of their common core only

All of the above

22. For sinusoidal waveform, the ratio of average value to r.m.s. value is

<img src='./qimages/3399-22.jpg'>

23. For an RLC series AC circuit, the current at series resistance is

maximum at lagging power factor

maximum at leading power factor

maximum at unity power factor

minimum at unity power factor

24. If v jb) and i then active power is given by

ac+ad

ac+bd

bc-bd

ad+bc

25. The voltage phasor of a circuit is 10<15° V and current phasor is 2 .-45° A. The reactive power in the circuit will be

17.32 VAR

10 ROUTE 2 VAR

8.66 VAR

None of these

26. If a capacitance is charged by a square wave current source, then the voltage across the capacitor will be

Square wave

Step function

Triangular wave

Zero

27. In the circuit shown below, the terminals A and B are short circuited, the current drawn from the battery is V V zero R 2R

<img src='./qimages/3399-27.jpg'>

28. In the following circuit, the equivalent capacitance between terminals A and B is C 2

<img src='./qimages/3399-28.jpg'>

29. The output voltage of a battery drops from 100 V with zero load current to 80 V when load current is 2 A. The internal resistance of the battery is

10 omegha

20 omegha

40 omegha

50 omegha

30. A charge of 0.1 coulomb moves through a given point in every 0.05 seconds. The current flowing through the point is

2mA

5mA

2A

5A

31. Which of the following capacitors are used in D.C. circuits

Mica

Air

Ceramic

Electrolytic

32. In an RLC series AC circuit, if frequency is below the resonant frequency, then

Xc=Xl

Xc<Xl

Xc>Xl

None of these

33. An R-L series AC circuit has R 10 ohm and 10 ohm. It is connected to an AC L voltage source, the phase angle between voltage and current is

30°

45°

60°

36.8°

34. The current I flowing in the following circuit is 10

<img src='./qimages/3399-34.jpg'>

zero

1A

-1A

A 3

35. The capacitance of a capacitor is not affected by

Plate area

Plate separation

Nature of dielectric

Plate thickness

36. A 220 200 W bulb and a 220 100 W bulb are connected in series across a 220 V supply, the power consumed by them will be

33.3 W

66.6 W

100 W

300 W

37. The direction of inducted e.m.f. can be found with the help of

Fleming's right hand rule

Kirchhoff's voltage law

Lenz's law

Laplace's law

38. If 1 ampere current is flowing through a 100 mH coil, then energy stored in the coil is

0.05 Joules

0.5 Joules

5.0 Joules

None of these

39. In the following figure, the equivalent resistance at terminals A and B will be

<img src='./qimages/3399-39.jpg'>

40. The maximum power dissipation in a resistance from a battery of electromotive force and internal resistance will be E2E2 E2E2

<img src='./qimages/3399-40.jpg'>

41. Two heater wires of equal length are connected first in series and then in parallel. The ratio of heat generated from series to parallel connection will be

4:1

2:1

1:2

1:4

42. When the current in a coil is increased from 2 A to 4 A in 0.05 seconds, the e.m.f. induced in the coil is 8 V. The self inductance of the coil is

0.8H

0.4H

0.2H

0.1H

43. The induced e.m.f. will be maximum when a conductor cuts the magnetic field at an angle of

15° 30° 45° 90° 30°

45°

60°

36.8°

44. A delta connected load with resistance of 6 ohm and inductive reactance of 8 ohm in each phase is supplied by a 3-phase, 400 50 Hz, AC supply. The value of total power drawn by the load is

28.8 kW

14.0 kW

10.8 kW

52.0 kW

45. The frequency of voltage generated in a 4-pole alternator rotating at 1800 r.p.m. is

25 Hz

30 Hz

60 Hz

None of these

46. A 50 Hz alternator will run at the highest speed if it is wound for

8 poles

6 poles

4 poles

2 poles

47. A transformer having 1000 turns in primary winding is connected to a single phase 250 V a.c. supply. For inducing 400 V in secondary winding, the number of turns in secondary winding must be

1600

1250

400

250

48. The field poles and armature core of a d.c. generator are laminated in order to reduce

Hysteresis loss

Eddy current loss

Weight

Speed

49. Which one of the following methods gives voltage regulation higher than the actual value in an alternator

ZPF method

mmf method

emf method

ASA method

50. If speed of a d.c. shunt motor is increased above the rated speed, then the counter e.m.f.

increases

decreases

remains unchanged

first increases and then decreases

51. The open current test in a transformer gives

iron losses

copper losses

friction losses

total losses

52. The mechanical power developed in a d.c. motor is equal to

power input core losses

power input mechanical losses

Armature current × counter e.m.f.

Armature current × supply voltage

53. An electric train employing a d.c. series motor is running at a fixed speed. When a sudden drop in voltage of supply takes place, then this results in

drop in speed and rise in current.

rise in speed and drop in current.

rise in speed and rise in current.

drop in speed with current unaltered.

54. A 220 V dc shunt motor is running at 500 rpm when armature current is 50 A. The value of armature resistance is 0.2 ohm. The speed of motor at the double torque will be

250 rpm

500 rpm

1000 rpm

476 rpm

55. A 10 kVA 220 V/220 50 Hz transformer shows 340 W in short circuit test and 168 W in open circuit test. Its efficiency at full load and 0.8 power factor lagging is approximately

92%

94%

96%

98%

56. If number of poles in lap wound d.c. generator are doubled, the generated e.m.f. will be

increased by a factor of 2

decreased by a factor of 2

increased by a factor of 4

unchanged

57. A d.c. series motor has linear magnetization characteristics and negligible armature resistance. The motor speed is

directly proportional to route T

inversely proportional to route T

directly proportional to T

inversely proportional to T where T load torque

58. The most common type of prime mover used for low speed alternators is

Steam turbine

Petrol engine

Hydraulic turbine

Diesel engine

59. When speed of an alternator is changed from 3600 rpm to 1800 rpm, the generated emf will be

one-half

twice

one-fourth

four times

60. The power factor of an alternator is determined by its

prime mover

speed

excitation

load

61. The efficiency of an ordinary transformer is maximum when

it runs at half of full speed

it runs at full load

copper losses are equal to iron losses

it runs at slightly overload

62. At light load, efficiency of a transformer is low. It is because

copper loss is small.

copper loss is high.

secondary output is low.

fixed loss is high with respect to output.

63. The essential condition for parallel operation of two single phase transformers is that they should have the same

Polarity

kVA rating

Voltage ratio

Percentage impedance

64. A transformer transforms

frequency only

voltage only

current only

voltage and current

65. Which of the following connections of a three phase transformer are best suited for 3-phase, 4-wire service

delta-delta

ghama-ghama

delta-ghama

ghama-delta

66. Transformers are rated in kVA instead of kW, because

load power factor is often not known.

total transformer loss depends on volt-ampere.

kVA is fixed where as kW depends on load power factor.

None of the above

67. A transformer has negative voltage regulation when its load power factor is

Zero

Leading

Unity

Lagging

68. A 4-pole dc generator runs at 1500 rpm. The frequency of current in armature winding is

zero

25 Hz

50 Hz

100 Hz

69. The no load current in a transformer lags the supply voltage by

0°

90°

110°

about 75°

70. Two mechanically coupled alternators deliver power at 50 Hz and 60 Hz respectively. The highest speed of alternators is

600 rpm

500 rpm

3000 rpm

3600 rpm

71. The heat run test of a transformer without its loading is performed by means of

Short circuit test

Open circuit test

Half time short circuit test and half time open circuit test

Sumpner's test

72. For a d.c. series motor, which of the following expression is correct assuming torque versus armature current characteristics unsaturated a

<img src='./qimages/3399-72.jpg'>

73. A d.c. series motor should never be started at

normal load condition.

full load condition.

no load condition.

slightly overload condition.

74. In a d.c. generator, 8 parallel paths and 16 brushes for collection of current are used. If voltage drop per brush is 1 then reduction in the induced e.m.f. will be

2V

4V

8V

16V

75. The input impedance of a common base transistor is

Medium

Low

High

Infinity

76. Transistor can be operated in

active region only

cut-off region only

saturation region only

All of the above

77. In a BJT

<img src='./qimages/3399-77.jpg'>

78. For any inverting amplifier, the input capacitance due to Miller effect

increases

decreases

remains constant

None of these

79. In an amplifier, if voltage shunt negative feedback is employed, then

the bandwidth decreases

the output resistance decreases

the input resistance decreases

the gain increases

80. Feedback in an amplifier is used to

control output

increase gain

decrease input resistance

stabilize gain

81. Out of the following hybrid parameters of a transistor which has unit of resistance

hf

hi

hr

ho

82. A transistor has following currents

IB=25mA B
IC= 4.975 A C
Then IE is equal to

5.225 A

4.95 A

5.0 A

None of these

83. When used as a voltage regulator, a zener diode is normally

forward biased

reversed biased

not biased

None of the above

84. The expression for voltage gain Av of a positive feedback amplifier is

<img src='./qimages/3399-84.jpg'>

85. In a single stage amplifier D.C and A.C load lines

are always parallel

are perpendicular to each other

cross each other at Q-point

are inclined but do not cross each other

86. Phase reversed of 180° as compared to input occurs in the output of

CE amplifier

CB amplifier

CC amplifier

All of these

87. Improper biasing of a transistor circuit leads to

excessive heat production in collector.

faulty location of load line.

heavy loading of emitter.

distortion in output signal.

88. When a P-N junction is reverse biased

it offers high resistance

its depletion layer becomes narrow

its barrier potential decreases

it breaks down

89. The current gain of a common emitter transistor is 50. The change in emitter current for a corresponding change of 5 mA in base current will be

50 mA

55 mA

250 mA

255 mA

90. If the maximum current of a half-wave rectified wave is 10 its r.m.s value is given by

3.10 A

5.0 A

6.37 A

7.07 A

91. A common emitter amplifier is characterized by

low voltage gain

very high output impedance

moderate power gain

signal phase reversal

92. The maximum rectification efficiency of a half-wave rectifier is

40.6%

81.2%

88.0%

100%

93. The ripple factor of a power supply is a measure of

its filter efficiency

its voltage regulation

its purity of output

diode rating

94. The power dissipation in a transistor is the product of

Emitter current and emitter to base voltage.

Collector current and collector to base voltage.

Emitter current and collector to emitter voltage.

None of the above

95. Consider the following circuit configurations

1. Common emitter

2. Common base

3. Emitter follower The correct sequence in increasing input impedance of these configuration is









96. The forbidden gap of a Germanium semiconductor material is

0.12 eV

0.72 eV

7.20 eV

None of these

97. In the following circuit, forward resistance of diode is zero. For the voltages shown at input and output of the transformer, the d.c. voltage across 5 ohm resistor will be

<img src='./qimages/3399-97.jpg'>

98. P-N junction diode is used for the following application

Amplifier

Detector

Radio valve

None of these

99. In the following figure, V1 8.0 V and V2 0 Which diode will conduct (assume ideal diodes)

<img src='./qimages/3399-99.jpg'>

100. Which one of the following is a non-maskable interrupt

RST 7.5

RST 6.5

RST 5.5

TRAP

101. A balanced modulator is used for generation of which of the following

DSB-SC signal

FM signal

PM signal

PAM signal

102. A FM wave is given as v 12 sin × 108 t 5 sin 1250 t). Its carrier frequency is

60.0 MHz

95.5 MHz

125.0 MHz

276.3 MHz

103. An operational amplifier has a differential gain of 100 and a common mode gain of 0.01. Its CMRR will be

20dB

40dB

60dB

80dB

104. An input of Vi 5.0 cos .t is given to an Op-Amp integrator circuit. If R 2.0 M ohm and C 1.0 µF, then output will be

10Wsin Wt

5Wsin Wt

-2.5 W sin Wt

-0.5 W sin Wt

105. The full scale output of an 8 bit DAC for 0 to 10 V range is

1.961 V

9.961 V

96.11 V

1.996 V

106. Memory range of a memory chip 1 K is

0000H to 03FFH

0001H to 01FFH

0000H to 02FFH

0000H to 04FFH

107. Which one of the following gate-symbol combinations is false

<img src='./qimages/3399-107.jpg'>

108. Which one of the following is equal to A B

A ·B-

A · B

A-· B

·

109. The basic memory cell in a DRAM is a

MOSFET

Capacitor

Capacitor and a MOS switch

Flip-Flop

110. Absorption of radio waves in atmosphere depends on

frequency of waves

distance from transmitter

polarisation of waves

polarisation of atmosphere

111. Each flip-flop in a 4-bit ripple counter introduces a maximum delay of 40 n sec. The maximum clock frequency is

2.65 MHz

6.25 MHz

5.26 MHz

6.52 MHz

112. Which IC is a decade counter

7476

7486

7404

7490

113. Consider following gates

1. NAND

2. NOR

3. XOR Out of these gates, the universal gates are

1and3only

2and3only

1and2only

1,2and3

114. How many flip-flops are required to build a binary counter circuit to count from 0 to 1023

1

6

10

23

115. The number of NAND gates required to implement a function A A B A BC is equal to

0

1

4

5

116. With reference to following logic circuit, the output will be

<img src='./qimages/3399-116.jpg'>

117. Which of the following are 3 byte instruction set

MV1A,32H

JMP2085H

MOVC,A

ADDB

118. In the following Op-Amp circuit, the output Vis o

<img src='./qimages/3399-118.jpg'>

119. Which of the following oscillators is used for generation of high frequency signal

RC phase shift oscillator

Blocking oscillator

Wein bridge oscillator

L-C oscillator

120. In a positive edge triggered JK flip-flop, J K 0 and clock pulse is rising, Q will be

0

1

showing no change

toggle

121. Kaplan turbines are used whenever the water head is

low

high

medium

and

122. The cost of fuel transportation is minimum in

Steam power plant

Diesel power plant

Hydro-electric plant

Coal based power plant

123. Economisers are used to heat

Coal

Air

Steam

Feed water

124. In thermal power plants, the pressure of working fluid cycle is developed by

Condenser

Superheater

Feed water pump

Turbine

125. A gas turbine power plant is best suited for

base load

peak load

emergency purpose

None of the above

126. Out of the following plant categories

Nuclear
Run-off river
Pump storage
Diesel

The base load power plants are

and

and

and

and

127. Which of the following components is not a part of hydro-electric plant

Penstock

Spillway

Surge tank

Economiser

128. Which one is not a commonly used coolant for fast breeder reactor

Water

Liquid metal

Helium

Carbon dioxide

129. Combined cycle power plants may need

MHD generator

Thermionic converter

Thermoelectric generator

All of the above

130. The pH value of water used for boiler of thermal power plant is

unity

7

slightly more than 7

10

131. The expression for power plant output in kilo-watt of a hydro-electric plant is given by 0.736 Q.Wh ·. 75 Q.Wh ·. o o

0.736 Q.W.h/75Xn0

0.736 Q.W.h.n0/75

0.736 Q.W.h.n0/0.736

None of these

132. A cable has inductance of 0.22 mH per kilo meter and capacitance of 0.202 µF per kilo meter. The surge impedance of the cable is

50 O

42 O

33 O

28 O

133. The first nuclear power plant was built in India at which place

Tarapur

Rana Pratap Sagar

Kalpakkam

Narora

134. Sag of conductors between two electric poles can be determined byWL2

WL2 /8T

WL2/16t

WL2 /2T

WL2/T

Where W weight per unit length of conductor in kg/m
L Distance between two poles in metre
T Tension in conductors in kg-m

135. The economic size of a conductor in transmission and distribution lines of electric power is decided by

Ohm's law

Kelvin's law

Kirchhoff's law

Faraday's law

136. Which alternator will have more number of poles

coupled to steam turbine

coupled to gas turbine

coupled to hydraulic turbine

None of the above

137. In an AC transmission line difference in phase of voltage at two ends of the line is due to

System voltage

Insulators

Resistance of line

Reactance of line

138. If 5000 kW power is transmitted at 220 kV in place of 11 kV, reduction in the value of electric current will be

90%

95%



10%

139. In long AC transmission lines, the receiving end voltage becomes greater than sending end voltage at light load or no load operation. This is due to

Ferranti effect

Skin effect

Proximity effect

Corona effect

140. For extra high voltage ac transmission lines, conductors used are

All aluminium

All steel

AAAC

ACSR

141. Which of the following relations is true for long transmission line

VS=AVR-BIR

VS=BVR+AIR

VS=AVR+BIR

VS=BVR-AIR

142. Which of the following is used for power factor improvement in transmission line

Three phase induction

An overexcited three phase synchronous motor running on no load

Three phase AC series motor

Choke

143. The connected load of a consumer is 2 kW and his maximum demand is 1.5 kW. The load factor of the consumer is

0.375

0.75

1.33

None of these

144. If diameter of each conductor of a transmission line is then the diameter of n-layer stranded conductor will be









145. The bundled conductor in EHV transmission line system provides

increased inductance

reduced capacitance

increased capacitance

increased voltage gradient

146. Corona losses in transmission lines are minimized when

conductor size is reduced.

smooth conductor is used.

sharp points are provided in the line.

current density in conductor is reduced.

147. The power loss in a transmission line depends on

current in the line.

resistance of the line.

length of the line.

All of the above

148. The main consideration for operating transmission line at high voltage is

to increase efficiency only.

to reduce power loss only.

to increase power transmission capability only.

All of the above

149. The presence of earth in case of overhead transmission line

increases capacitance

increases inductance

decreases capacitance

decreases inductance

150. Effect of increase in temperature in an overhead transmission line is

to increase stress and length both

to decrease stress and length both

to decrease stress and increase length

None of the above

151. A 0-10 A ammeter has a guaranteed accuracy of of full scale deflection, the limiting error while reading 2.5 A will be







None of these

152. The constant of a given energymeter is 500 revolution/kWh. At the test 4.4 kW full load, meter completes 50 revolutions in 86 seconds. The percentage error of the meter is

-4.86%

4.86%

2.0%

3.0%

153. The most efficient form of damping employed in electric instruments is

Air friction damping

Fluid friction damping

Eddy current damping

None of the above

154. Which of the following instruments is equally accurate on ac as well as dc circuits

PMMC voltmeter

Dynamometer wattmeter

Moving iron ammeter

Induction wattmeter

155. The moving system of an indicating type of electrical instrument is subjected to

a deflecting torque

a controlling torque

a damping torque

All of the above

156. Energy meter runs slowly even if power is not used. This error is called

Speed error

Phase error

Creeping error

None of these

157. The type of instruments used mainly for standardizing instruments in laboratories is

Indicating instrument

Integrating instrument

Absolute instrument

Recording instrument

158. What will happen if a voltmeter is connected like an ammeter in series of the load

The meter will burn out.

The measurement will be too high.

The same current will flow as would have been with ammeter in circuit.

There will be almost no current in the circuit.

159. Series resistance required to read 0-250 V with a moving coil instrument of internal resistance 2 ohm and full scale deflection of 50 mA is

49998 O

4998 O

498 O

49.8 O

160. Which of the following is not a method of resistance measurement

Ammeter Voltmeter method

Post Office box method

Ohm Meter method

Two wattmeter method

161. Internal resistance of a micro-ammeter is 500 ohm. Shunt resistance required to increase its range from 0-100 µA to 0-10 A will be approximately

(a)0.05 omegha

0.005 omegha

0.5 omegha

5.0 omegha

162. Hay bridge is suitable for measuring following type of inductance

having Q greater than 10.

having Q less than 10.

having any value of Q.

having phase angle of reactance very large.

163. The dielectric loss of a capacitance can be measured by

Hay bridge

Maxwell bridge

Anderson bridge

Schering bridge

164. In a particular meter, the deflecting torque is directly proportional to the current flowing through it, the type of meter is

moving coil

moving iron

induction

electro-static

165. For measurement of low resistance, the bridge used is

Wheatstone

Kelvin

Maxwell

Anderson

166. While measuring power in a three phase load by two wattmeter method, the reading of two wattmeter are equal and opposite, when

load is balanced

power factor is unity

phase angle is between 60° to 90°

the load is purely inductive

167. Megger is used to measure

very high resistance or insulation resistance.

low resistance.

high resistance.

very low resistance.

168. If a dynamometer wattmeter is connected in an ac circuit, the power indicated by the wattmeter will be

volt-ampere product

average power

peak power

instantaneous power

169. The Maxwell bridge is used for measuring

Capacitance

Dielectric loss

Inductance

Phase angle

170. A compensated wattmeter has its reading corrected for error due to

Frequency

Friction

Power consumed in current coil

Power consumed in pressure coil

171. A null type of instrument as compared to a deflecting type instrument has

higher accuracy

lower sensitivity

faster response

All of the above

172. A digital voltmeter has a read-out range from 0 to 9999 counts. When full scale reading is 9.999 the resolution of the instrument will be

100mV

99mV

9mV

1mV

173. A VTVM can be used to measure

dc voltage only

ac voltage only

both and

None of the above

174. The sensitivity of a voltmeter using 0-5 mA meter movement is

200 omegha/v

150 omegha/v

100 omegha/v

50 omegha/v

175. Moving coil instruments have which one of the following scales

Logarithmic scale

Uniform scale

Non-uniform scale

Squared scale

176. Super conducting materials can be used for

ore refining.

magnetic levitation in high speed trains.

medical resonance imaging.

All of the above

177. Ferrites are types of

magnetic material

conducting material

semiconducting material

insulating material

178. In which material, valence electrons are tightly bounded to their parent atoms

Conductor

Semiconductor

Insulator

Magnetic

179. The disc of domestic supply energy meter is made of which material

Zinc

Copper

Aluminium

Silver

180. The material of hair spring used in measuring instruments is made of which of material of the following

Copper

Bronze

Alnico

None of these