1. If there is a regular moment of …… within a material, we say that an electric current is flowing1) protons 2) electrons3) atoms 4) ions

2. The rate of flow of an electric current is measured in 1) coulombs 2) amperes 3) ohms 4) mhos

3. One coulomb represents a quantity of 1) 0.624X1018 electrons 2) 624X1012

electrons3) 6.24X1019 electrons 4) 6.24X1018

electrons

4. If three coulombs of electricity flow through a conductor in three seconds the current is 1) one ampere 2) one half ampere3) six ampere 4) one third ampere

5. The presence of an electric current is made known by1) flashing 2) effects produced3) cracking 4) electric shock

6. When an electric current flows through a conducting liquid, a …… change is produced1) chemical 2) magnetic 3) mechanical

7. In mathematical form ohm’s law can be written as1) V I=R 2) V =IR 3) V=I/R 4) VR=I

8. Ohm’s law does not apply to1) conductors2) conductors when there is change in temperature3) semi-conductor4) a.c. circuits

9. If a piece of metal wire is stretched, its resistance will increase1) True 2) False

10. The material used for fuse must have1) low melting point and low specific resistance2) low melting point and high specific resistance3) high melting point and low specific resistance

11. When an electron is removed from an atom it becomes1) a positive ion 2) an anode3) a cathode 4) a negative ion

12. Absolute permitivity of vacuum is taken as1) 8.854X10-6 farad/m 2) 8.854X10-12

farad/m3) 8.854X10-9 farad/m

13. Relative permittivity of vacuum is 1) zero 2) 8.854X10-6 3) unity

14. Dielectric strength of a material depends on 1) moisture content 2) thickness

3) temperature 4) all the above15. What will happen to an insulating medium of voltage more than the breakdown voltage is applied or it1) it will get punctured 2) it will become magnetic3) it will melt 4) its molecular structure will change

16. Capacitors are said to1) block a.c. and pass d.c. 2) block d.c. and pass a.c.3) pass a.c. and d.c. 4) block a.c. and d.c.

17. To increase the capacitance of a capacitor, the plates must be placed1) further apart 2) closer together3) in series 4) made smaller

18. In a radio a gang condenser is a type of 1) air capacitor 2) paper capacitor3) ceramic capacitor 4) electrolytic capacitor

19. In a capacitor the electric charge is stored in1) metal plates2) dielectric3) dielectric as well as metal plates

20. 4 condensers of 4 F each are connected in parallel. Their equivalent capacitance will be1) 16 F 2) 64 F 3) 4 F 4) 1 F

21) When two capacitors C1 and C2 are connected in series, the effective capacitance is C1+C2

1) True 2) False

21. An uncharged capacitor is connected across a charged one. There will flow an impulsive current through the circuit.1) True 2) False

22. Current and voltage in an a.c. resistive circuit are 1) 900 out of phase2) in phase3) 900 out of phase current leading voltage4) 1800 out of phase.

23. Current and voltage in a.c. inductive circuit are1) 900 out of phase2) in phase3) 900 out of phase voltage leading current4) 900 out of phase voltage lagging current

24. Alternating current frequency is the number of 1) alternation per minute 2) cycles per minute3) alternation per second 4) cycles per secon4)

25. The greatest value attained during one half of the cycle is called the1) peak value 2) average value

3) r.m.s value 4) effective value

26. The root mean square (r.m.s) value of a.c. is the same as1) instantaneous value 2) effective value3) average value 4) maximum value

27. The r.m.s value of a sine wave is equal to 1) 0.637 max. value 2) 0.707 max. value3) 0.506 max. value 4) 1.414 max. value

28. Form factor is defined as1) r.m.s value/peak value2) max. value/r.m.s value3) r.m.s value/average value4) effective value/r.m.s value

29. The value of form factor for a pure sine wave is 1) 1.414 2) 0.707 3) 0.637 4) 1.11

30. The value of peak factor for a pure sine wave is 1) 1.414 2) 0.707 3) 0.637 4)1.11

31. At resonance, the phase angle is equal to 1) 1800 2) 900 3) 450 4) 00

32. The condition of resonance is 1) XL XC 2) XC XL 3) XL=XC

33. According to KCL as applied to a junction in a network of conductors

1) total sum of currents meeting at the junction is zero2) no current can leave the junction without some current entering it.3) Net current flow at the junction is positive.4) Algebraic sum of the currents meeting at the junction is zero

34. Kirchhoff’s current law is applicable to only.1) closed loops in a network2) electronic circuits3) junctions in a network4) electric circuits

35. Kirchhoff’s voltage law is concerned witha. I R drops 2) battery e.m.f.s3) junction voltage 4) both a and b

36. According to KVL, the algebraic sum of all I R drops and e.m.f.s in any closed loop of a network is always

1) zero 2) positive 3) negative 4) determined by battery e.m.fs

37. The algebraic sign of an IR drop is primarily dependent upon

1) amount of current flowing through it2) value of R3) direction of current flow4) battery connection

38. The unit of absolute permittivity of a medium is

1) joule/coulomb 2) newton-meter3) farad/meter 4) farad/coulomb

39. The unit of electric intensity is 1) joule/colomb 2) Newton / coulomb3) volt/metre 4) both b and c

40. Inside a conducting sphere,____ remains constant

1) electric flux 2) electric intensity3) charge 4) potential

41. A capacitor consists of two1) insulators separated by a dielectric2) conductors separated by an insulator3) ceramic plates and one mica disc4) silver-coated insulators

42. A capacitor that stores a charge of 0.5 C at 10 volts has a capacitance of --------- farad1) 5 2) 20 3) 10 4) 0.0543. If e1=A sin wt and e2=B sin (wt-), then 1) e1 lags e2 by 2) e2 lags e1 by 3) e2 leads e1 by 4) e1 leads e2 by

44. The unit of conductivity is :1) ohms 2) -m 3) Siemens 4) candela

45. In case of short circuit :1) voltage is , current is 2) voltage is 0, current is 03) voltage is 0, current is 4) voltage is , current is 0

46. Capacitance of spherical capacitor is :1) 40rd 2) ¼0d3) 40r(b-a)/ab 4) 40r (ab)/(b-a)

47. The energy stored in a capacitor is given by :1) ½ C2V 2) ½ QV3) C2/2Q 4) None of the above.

48. Capacitance of a variable capacitor is given by :

1) n. 0rA/d 2) 0rd/A(n-1)3) (n-1) 0rA/d 4) 40r(b-a)/(ab)

49. The % tolerance for gold is 1) 5% 2) 2%3) 10% 4) 20%

50. In colour coding of resistance. If the colours are brown, black, red the value of resistance is :1) 100 2) 1000 k3) 100 k 4) 1 k

51) The direction of magnitude field set up in a current carrying conductor can be found out by1) flemings left hand rule 2) cork screw rule3) flemings right hand rule 4) thumb rule

52) The unit of mmf is –1) volt 2) amp-turnsc) coulomb 4) None

53) The low that induced emf and current always oppose th cause producing it is discovered by 1) Fleming 2) faraday 3) Lenz 4) Maxwell

54) What are the minimum requirements to cause the flow of current1)a voltage source and a conductor 2) a voltage source conductor and insulator3) a voltage source, switch and resistor4) a voltage source ammeter and a conductor

55. The co-efficient of self inductance of a coil is defined as – 1) /NI 2) NI/ 3) N/I 4) I/N

56. Tesla is a unit of –1) flux 2) field strength3) flux density 4) none

57. The direction of magnetic lines of forces – 1) from one end of magnet to another2) from north, pole to south pole3) from south to north pole4) none

58. Battery is a device that –1) generate emf by chemical action2) converts mechanical energy into electrical energy3) converts heat energy into electrical energy4) None

59. In a primary battery –1) chemical action is reversible2) chemical action is irreversible3) no chemical action takes place4) chemical action takes place

60. Active elements in a lead acid battery –1) nickel hydrate and iron oxide2) lead peroxide and sponge lead3) manganese dioxide and carbon4) sponge lead

61) Electrolyte used in lead acid battery is1) sulphuric acid 2) caustic potash3) nitric acid 4) none

62) When the temperature increased, specific gravity of electrolyte1) increases 2) decreases3) remains same 4) none

63) The capacity of a battery is expressed in 1) ampere-hour 2) ampere volt3) percentage 4) volts

64) During discharge of a battery voltage of cell –1) decreases 2) increases3) remains constant 4) none

65. The condition in ohm’s law is that1) the temperature should remain constant2) ratio V/I should be constant3) the temperature should vary

4) current should be proportional to voltage

66. Kirchoff’s law states that in a closed loop of a circuit 1) The total currents, algebraically summed is zero 2) the algebraic sum of the potential differences is zero 3) the voltage across the components is zero4) none

67. Angle between voltage and current is called –1) peak factor 2) power factor3) form factor 4) none

68. The ratio of maximum value to r.m.s. value is called 1) peak factor 2) ferm factor3) utilisation factor 4) maintenance factor

69. The reactance of an inductance L connected to an a.c. source frequency f is -1) fl 2) f2l3) 2 fl 4) ½ fl

70. If a capacitor is connected to an a.c. source the current – the source voltage by1) lags 900 2) lags 450

3) leads 900 4) none

71. If a circuit the voltage. Is doubled and the resistance is cut in half at the same time the current will be 1) doubled 2) a quarter3) a half 4) four times as high

72. What is meant by permeability –1) strength of a permanent magnet2) strength of a electromagnet3) repulsion of two similar poles4) conductivity of a material for the magnetic flux

73. The parallel conductor are carrying current in the same direction. Which of the following statement is correct1) there is a repelling force2) the force increases when current decreases3) there is an attracting force between the conductors4) the force increases when the distance between conductor increases

74. The direction of the induced current depends upon 1) length of conductor2) speed of movement of conductor3) strength of magnetic field4) direction of magnetic field

75. Which is the symbol and unit for inductance 1) Rm weber (wb) 2) XL henry (h)3) L gauss (G) 4) henry (H)

76. In a stationery conductor an emf can be induced by 1) a changing magnetic field 2) positive and negative charges

3) a steady magnetic field 4) none

77. The induced emf is max. if the conductor cuts the magnetic field at1) 00 2) 450 3) 900 4) none

78. The power factor of a purely resistive circuit is –1) zero 2) lagging3) leading 4) unity

79. Power factor is the rates of - 1) Z/R 2) R/Z3) XL/Z 4) Xc/z

80. A R-L-C series ckt. Has a resistance of 6, inductive reactance of 8 and capacitive reactance of 16. The impedance will be 1) 10 2) 16 3) 8 4) 6

81. The max. value of the cycle is known, the r.m.s. value can be found at – 1) 0.707 X instantaneous value2) 0.606 X instantaneous value 3) 0.707 X emax value 4) 0.707 X Eav value

82. a.c. can be easily lowered and raised by – 1) converter 2) motor generator set3) transformer 4) rectifier

83. The max. & min. valued of power factor is – 1) 1 and 0 2) +1 and –13) +1 and –5 4)+ 5 and –5

84. Kirchoff’s laws are applicable to 1) dc circuit only 2) both dc and ac circuits3) a.c. circuit only 4) none

85. An alternating current or voltage is that which 1) changes in direction only2) changes in magnitude only3) changes in both magnitude and direction4) has a random movement of electron

86. In an a.c. circuit containing inductance only – 1) current lead voltage by 90 02) current lags behind utg by 90 03) current and voltage are in phase4) voltage leads current by help a cycle

87. Relation between frequency and time period – 1) f =T 2) f = 1-T 3) f = T-1 4) f = 1/T

88. What is meant by frequency of an alternating voltage 1) No of full periods in one second2) no. of direction reversals in one second3) no. of direction reversals in one minute4) no. of half periods in one second

89. What is meant by “current and voltage are in phase“1) voltage and current are of the same magnitude2) voltage and current have the same frequency

3) the voltage leads the current in time4) voltage and current reach their max. and zero value at the same time

90. When current passes through a conductor, the resultant effect is 1) a magnetic field is produced2) magnetic as well as heating effect 3) only heating effect4) only chemical effect

91. The nature of current flowing in armature of etc machine is –1) dc 2) alternating 3) pulsating

92. Brushes are provided in a dc machine for 1) providing a path for the flow of current2) preventing sparking3) reducing losses4) none

93. The armature of a dc machine is laminated to reduce 1) eddy current loss 2) hysterisis loss3) copper loss 4) friction loss

94. The emf generated of a given dc generator depends upon1) flux only 2) speed only3) flux and speed 4) terminal voltage

95. If the speed of prime mover of a dc generator is increased the generated emf1) increases 2) decreases3) remains constant

96. Commutator in a ac generator is used for – 1) converting dc to ac 2) changing ac to dc3) reducing friction 4) collecting the current from armature

97. Commutator of dc motor serves the purpose of 1) changing ac into dc 2) converting dc into ac3) avoiding arc at brushes 4) reducing friction98. On loading the speed of a dc shunt motor1) increases 2) remains constant3) slightly decreases 4) decreases sharply

99. A dc series motor is started on no load its speed is 1) zero 2) normal 3) infinite

100.Which of the following motors gives a high starting torque1) series motor 2) shunt motor3) compound motor

101.In dc machine at max. efficiency1) Iron losses = armature copper losses2) variable losses = constant losses3) iron losses + mechanical losses + armature copper loss + shunt field loss4) none

102.Why is the air gap between the yoke and armature of an electric motor kept smaller –1) to achieve a stronger magnetic field2) to avoid overheating of machine3) both a & b4) none

103.The function of starter in a dc machine1) to avoid excessive current at starting2) to control speed3) to avoid armature reaction4) none

104.An emf is induced in the windings of an armature of a generator when the armature rotates in1) alternating magnetic flux2) magnetic field3) electrostatic flux 4) electromagnetic flux

105.If the speed of dc generator is increased the generated emf 1) increases 2) decreases3) remains constant 4) decreases then increases

106.If speed of dc shunt motor increases, the back emf1) increases 4) decreases3) remains constant 4) none

107.The efficiency of any electrical machine/ apparatus will be high if 1) its losses are minimum 2) its losses are more 3) voltage applied is constant 4) current drawn is min.

108.The direction of rotation of a dc shunt motor is reversed by – 1) reversing armature connection2) interchanging the armature and field connection3) adding resistance to field circuit4) both a and c

109.Which of the following dc motor has the least drop in speed between no load to nominal load – 1) shunt motor 2) series motor 3) compound motor

110.Which of the following motor is used to drive the constant speed line shafting lathes, blowers and fans1) dc shunt motor2) dc series motor3) commutative compound motor4) none

111. DC series motor are best suited for traction because1) torque is proportional to the square of armature current and speed is inversely proportional to torque2) torque is proportional to the square of armature current and speed is proportional to torque

3) torque and speed are proportional to square of armature current4) none

112. An ideal dc generator has a regulation of – 1) zero 2) 50% 3) 75 % 4) 100%

113. A dc generator can be termed as –1) rotating amplifier 2) prime mover3) power pump 4) none

114. The function of equalising connections in a lap wound dc generator is –1) To neutralise the armature reaction effect2) to avoid unequal distribution of currents at brushes3) to avoid shot circuit current4) none

116. Transformer is used to change the values of 1) voltage 2) frequency3) power 4) power factor

117. The path of magnetic flux in a transformer has-1) high reluctance 2) low resistance3) high conductivity 4) low reluctance

118. Transformer is a1) rotating device 2) static device3) magnetic device

119.Transformer works on1) ac 2) dc3) ac and dc both 4) pulsating dc

120.Transformer works on the principle of –1) self induction2) mutual induction3) faraday’s law and electromagnetic induction4) self and mutual induction both

121.Rating of transformer is given in1) KVA 2) KVAR 3) KW 4) Watts122.If a higher voltage is given to primary and lower voltage is taken from secondary of transformer is it called1) step up 2) step down3) instrument transformer 4) stabiliser

123.The transformation ratio of a transformer is –1) I 2/ I 1 2) N1 / N 2

3) N 2 / N 1 4) All

124.The emf induced in secondary winding depends upon 1) no. of turns 2) flux 3) supply frequency 4) all

125.When the secondary of the transformer is loaded, the flux in the transformer will –1) remain constant 2) directly proportional to secondary current3) directly proportional to the current drawn by primary 4) none

126.When secondary of the transformer is loaded, the current in primary side will –1) not be effected2) increase3) decrease4) be the sum of no load current and excessive current drawn due to secondary winding

127.Electric power is transferred from one coil to the other coil in a transformer –1) electrically 2) electro-magnetically3) magnetically 4) physically

128.A transformer operates1) always at unity power factor2) has its own power factor3) at a power factor below a particular value4) at power factor depending on the power factor of load

129.The laminations are made from1) silicon sheet steel2) nickel alloy steel stamping3) low carbon steel4) chrome sheet steels

130.Which of the following is a correct statement about eddy current1) Eddy current improves the efficiency of a motor

2) 2) eddy current heat up the metal part3) eddy current used for arc welding 4) none

131.The steel for construction of transformer core is made to have1) high permeability and loss hysterisis loss2) low permeability and high hysterisis loss3) low permeability and low hysterisis loss4) high permeability and high hysterisis loss132.As compare to an amplifier, transformer can not 1) increase the output voltage2) increase the o/p current3) increase output power4) none

133. The voltage transformation ratio is 1) E 1 / E 2 2) N 1 / N 2

3) E 2 / E 1 4) none

134. In a transformer a sinusoidal emf –1) lags the flux inducing it by 180 0

2) lags the flux inducing it by 90 0

3) leads the flux inducing it by 180 0

4) leads the flux inducing it by 90 0

135. The no load current of a transformer in terms of full load current is usually –1) 1 to 3 % 2) 3 to 15 %3) 9 to 12 % 4) 12 to 20 %

136. If in a transformer the secondary turns are doubled and at the same time the primary voltage is reduced by half, then the secondary voltage will –

1) be halved 2) be four times as high3) not change 4) be reduced to a quarter

137. Which of the statement given below is correct for the auto transformer1) it has to separate windings connected in series externally2) it has only one winding3) it can only step down the voltagemost 4) suitable for power transformation

138. In any transformer the voltage per turn in primary and secondary remains –1) always same 2) always in ratio of K3) always different 4) sometimes same

139. In a single phase transformer the primary and secondary induced voltages are 1) 180 0 out of phase2) 90 0 out of phase3) in phase 4) none

140.An ideal transformer is one which1) has a common core for its primary and secondary windings2) has no losses and magnetic leakage3) has core of stainless steel and windings of pure copper metal 4) has interleaved primary and secondary windings

141.In an ideal transformer the no load primary current is 1) lags behind v1 by 90 0 2) is in phase with v1 3) leads v1 by 90 0

4) lags v 1 by an angle lying b / w 0 0 and 90 0

142.By definition a step down transformer is one in which 1) secondary current is more than primary current 2) secondary turns are less than primary turns3) secondary winding consists of thinner copper wire4) secondary power is less than primary power

143.The r.m.s value of a.c. is the same as :(1). Instantaneous value (2) effective value (3) average value (4) maximum value

144. The r.m.s value of a sine wave equal to :(1). 0.637 max. value (2) 0.707 max. value(3) 0.506 max. value (4) 1)414 max. value

145.Form factor is defined as :(1). r.m.s value /peak value (2) max. value/r.m.s value (3) r.m.s value/average value (4) effective value/r.m.s value

146.A unique feature of wire wound resister is its 1) low power rating 2) very high stability3) low cost 4) smaller size

147. The working voltage of a capacitor in an ac circuit should be

1) equal to average voltage2) at least 20% smaller than the highest applied voltage3) at least 50% greater than the highest applied voltage4) at least 50% less than the r.m.s valve of applied voltage

148. Kirchhoff’s laws can be used for 1) ac only 2) dc only3) ac & c both4) for rectified ac & pulsating dc

149. In practice, earth is chosen as a place of zero electric potential because it1) is non conducting2) is easily available3) has almost constant potential4) keeps loosing & giving electric energy every day

150. Magnetic ring type amplifier is used as 1) inductor2) simple saturable reactor circuit 3) unsaturated full wave rectifier 4) signal amplifier in communication circuits

151. Copper loss of a transformer is caused by 1) overheating 2) reluctance 3) eddy current loss & hysterisis loss4) opposition of the conductor comprising the coil turn

152. The % tolerance of the colour code ‘yellow’ is 1) two 2) three 3) four 4) five

153. During discharge _______ is formed on both the & negative plates of lead acid cell1) lead nitrate 2) lead acetate3) lead oxide 4) lead sulphate

154. If Ni-cd battery contains high charge, the positive plate contains1) Pbo2 2) Ni(OH)2

3) NaOH 4) Ni2O2 & Ni2O3

155. The direction of rotation of a three phase induction motor can be changed simply by 1) reversing two of the leads to the motor2) reversing connections to the starting winding and armature winding together3) using an addition winding with a capacitor connected across4)increasing the size of the armature winding

156. The induced emf generated in an inductor1) opposes the applied voltage2) boosts the applied voltage3) creates an induced magnetism4) creates eddy current in the conductor

157. The ratio of effective valve to an average valve of an alternating quantity is called1) peace factor 2) r.m.s. valve 3) form factor 4) max. instantaneous value

158. Eddy current can be reduced by 1) reducing the thickness of the conductor2) replacing the solid core with several insulated thin metal plated3) applying high frequency a.c.4) simply using a mica layer between coil & core

159.When a current containing a.c. & d.c. components tries to flow through a capacitor, it blocks 1) a.c. component2) both a.c. & d.c. components3) d.c. components4) neither a.c. nor d.c. components

160.Which one of the following transformer requires a jumper when it is not in use ?1) power transformer 2) auto transformer3) RF transformer 4) current transformer

161.Which one of the following generator is not used in a.c. power generation system?1) shunt wound generator 2) series wound generator3) split phase generator 4) compound wound generator

162.A series circuit is assured in which the applied voltage is 110 volts at 60 C.P.S. frequency and the capacitance of a condenser is 80μF. Find the capacitive reactance1) 33.2 2) 191 3) 30.9 4) 49.33

163.A moving iron instrument can be used for 1) a.c. only 2) d.c. only3) a.c. & d.c. both 4) neither a.c. nor d.c.

164.When a capacitor, inductor & a resister are connected in series, the effective impedence is equal to

__________1) (XL + XC)2 2) √(XL + XC) + R3) [R2 – (XL + XC)2]½ 4) [R2 + (XL - XC)2] ½

165.If a winding is completely shorted in a transformer 1) it will become cold 2) it will damage the load3) it will become over heated4) its performance will be unaffected

166. “When a current carrying conductor is placed in a magnetic field, it tends to rotate” this principle is used in1) generator 2) motor3) hotwire instrument 4) rectifier

167. When heavy starting torque is required, we use1) compound wound 2) shunt wound motor3) series wound motor 4) d.c. motor

168. The positive and negative plate of a lead acid battery is 1) positive lead oxide & negative pure lead

2) positive lead peroxide and –ve spongy lead3) positive is carbon rod and –ve is zinc plate4) positive is pure lead and –ve spongy lead

169. In a constant current charging system, a battery requires constant attention at the end of charging to avoid1) sulphation of battery 2) spilling of electrolyte3) evaporation of electrolyte 4) danger of over heating

170. Buckling of the plate can be avoided by using 1) an extra negative 2) by sulphation treatment 3) by charging the battery with very low rate 4) by amalgamating the plate with hydrogen peroxide

171. While diluting the acid to get required S.G. 1) Water is slowly added to acid2) acid is slowly added to water 3) both are added simultaneously 4) any one 1 or 3

172. While testing the S.G. of the electrolyte of a nickel cadmium battery, it shows a reading of 1300. That means 1) the battery is fully charged 2) the battery is moderately charged 3) the battery has lesser charge 4) the charging state can’t be predicted

173. The symptom of a fully charged lead acid battery is 1) free gassing 2) Specific gravity at higher than 1.260 on 3 consecutive reading 3) voltage should be more than 2.1 volt/cell 4) all above may be present

174. The separator used for Ni-Cd battery is 1) nylon coated with cellophane 2) wood packs

3) teak wood 4) glass wool

175. The neutralising agent for H2SO4

electrolyte is 1) KOH 2) HCL3) 5% Bicarbonate of soda solution 4) Vinegar

176. How can the state of charge of Ni-cd battery be determined?1) by measuring the S.G. of the electrolyte2) by a measured charging & discharging3) by the level of electrolyte 4) by the CCV measured by a voltmeter

177. What happens to the current in a step-up transformer with 1:4 turns ratio?1) current is reduced by 1:4 ratio2) current is increased by 1:4 ratio3) current is reduced by 4:1 ratio4) current is increased by 4:1 ratio

178.The purpose of providing bottom grooves underneath the plates in a lead acid battery container is to1) allow for convection of the electrolyte for cooling of the plates2) ensure that the electrolyte’s quantity and plate area is adequate 3) prevent sediment build up from contacting the plates and causing a short circuit4) prevent escape of electrolyte but allow

180. Which one of the following has comparatively long service life & low maintenance cost for aircraft 1) lead acid battery 2) dry cell3) Nickel cadmium battery 4) sodium sulphur battery

181. If the supply frequency in an aircraft falls more than 10% from the rated value 1) the equipment may be over heated 2) the equipment may be over cooled 3) nothing will happen 4) we cannot predict anything

182. In Fleming’s right hand rule, the thumb indicates 1) direction of induced emf2) direction of magnetic field 3) direction of motion of conductor 4) direction of current flowing in circuit

183. The force required to wipe out the residual magnetism is called

1) retentivity 2) magnetising force3) coercive 4) permeability

184. The brushes connected with commutator is placed 1) 90º away from its neutral position 2) 180º away from its neutral position 3) in neutral position 4) 270º away from its neutral position

185. In two parallel plate capacitor, the capacitance can be increased by 1) increasing the cross section area of the plates 2) increasing the distance between the plates 3) reducing the dielectric constant of dielectric medium 4) all are correct

186. At the end of normal discharge, the internal resistance of a lead acid cell is more than 1) twice as high as it is when fully charged 2) thrice as high as it’s when fully charged 3) half as high as it’s when fully charged 4) one third as high as it’s when fully charged

187. The separators used in lead acid battery have vertical ribs on the side 1) facing the positive plate 2) facing the negative plate 3) facing both the positive & negative plate

4) half part facing positive plate & half part facing negative plate

188. Hydrogen will be released at __ plates and oxygen will be released at ____ plates of a Ni-cd battery 1) negative, positive 2) negative at charging & positive at discharging3) positive, negative4) positive ( at discharging) & negative ( at charging)

189. “ Plug in holders” & “clip” type holders are used for 1) heavy high capacity fuses & current limiters 2) circuit breakers3) switches4) thermal protectors

190. The most accurate readings from ammeter can be obtained at approximately1) one third scale deflection 2) half scale deflection 3) one fourth scale deflection 4) nine tenth of scale deflection

191. The sensitivity of a voltmeter is represented by 1) volts per ohm 2) ohms per volt 3) ohms per ampere 4) amperes

192. The purpose of a growler test is to determined the presence of 1) an improper capacitor 2) a shorted armature 3) a broken field frame 4) a broken voltage regulator connection

193. One of the most satisfactory method of overcoming the effect of armature reaction is the use of 1) interpoles 2) shaded poles3) addition windings 4) additional brushes

194. Which one of the following method is used to increase the output voltage of a d.c. generator?1) increasing the number of winding in armature2) increasing the speed of rotation of the armature3) introducing inter-poles in the field frames4) introducing shaded pole inside the generator

195. Two spiral conductor are placed face to face, If d.c. current flows through the coils in same manner what will happen 1) attraction 2) repulsion3) attraction for one alternation & repulsion for the next alternation4) no affect

196. The eddy current loss of a transformer comes under 1) copper loss 2) iron loss 3) hysterisis loss 4) mechanical loss

197. A lead acid battery with 12 cells, connected in series (OCV=2)1 volts per cell) supply 10 amp. Current to a load of 2 resistance. Find the internal resistance of the battery 1) 0.52 2) 5 3) 2.52 4) 5.52

198. The vibrating reed type of frequency meter works on the principle of 1) mechanical resonance 2) electrical resonance3) impedance 4) mutual induction

199. If an instrument ( PMMC/MI) having an accuracy of 2% and the actual value of the current to be measured is 200 unit then the meter indication will be1) 200 to 202 2) 196 to 2003) 200 to 204 4) 196 to 204

200. The varmeter is used to measure 1) true power 2) reactive power3) applied power 4) reactive impedance

201. The power factor in a.c. circuit is 1) ratio of true power to apparent power 2) ratio of apparent power to true power 3) ratio of reactive power to ideal power 4) ratio of reactive power to applied power

202. Which one of the following parts is not essential for d.c. generator 1) armature 2) slip ring3) split ring 4) commutator

203. The voltage coil of the vibrating type voltage regulator is connected________ with the load 1) series 2) parallel 3) in series with the field coil & in series with the load4) none of these

204. A ‘ continuity tester’ is a 1) voltmeter 2) ammeter 3) ohm meter 4) wattmeter

205. The range of voltmeter can be increased by the use of additional series 1) multipliers 2) voltage resistors 3) shunt 4) none of these

206. The internal resistance of most vented Ni-Cd battery is 1) vary high (grater than few mega ohm)2) moderately high (approximately few k ohm)3) very low ( less than 1μ per cell)4) none of these

207.Which of the following material has nearly zero temperature coefficient of resistance1) Copper 2) Carbon3) Manganin 4) Mica

208.You have to replace a 1500 Ω resistor in a radio. You have no 1500 Ω resistor but have several 1000 Ω resistor, which you would connect:1) three in parallel2) three in series3) two in parallel and one in series4) two in parallel

209. When two resistances are connected in series they have1) same resistance value2) same voltage across them3) same current passing through them4) different resistance value

210. In a parallel circuit, all component must1) have the same p.d across them2) have same value3) carry equal current4) all

211. The current ratting of a 1 k Ω , ½ W resistor is1) 2.23A 2) 1A 3) 22.36MA 4) None

212. Four 1)5V cells are connected in parallel . The output voltage is1) 1.0V 2) 1.5V 3) 6.0V

4) None

213. The emf of a given cell is1) Distributive 2)Variable3) Constant 4) Less than terminal P.d

214. A Leclanache cell has1) A Depolariser2) A cathode of carbon3) An Electrolyte of H2SO4

4) Large current capacity

215. A standard cell is primarily used1) For supplying large currents2) as a source of energy3) For providing variable voltage4) As a secondary standard of voltage

216. A simple potentiometer is correctly called a 1) Current divider 2) Voltage stabilizer3) Variable resistor 4) Voltage divider

217.According to the commonly used sign convention for voltages :1. A fall in voltage considered positive2. A rise in voltage is considered positive3. IR drop is taken as negative4. Battery EMF is taken as positive

218. The unit of capacitance is1) Farad 2) Coulomb 3) Volt 4) Metre

219. The EMF of a fully charged lead Acid cell is about1) 1.21 2) 2.1 3) 1.8 4) 1.4

220. The neutrons in a nucleus have 1) Positive charge 2) Negative charge3) No charge 4) 3 electrons

221. The weight of proton is approximately1) 1000 times than e-2) 1240 times than e-

3) 1990 times than e-4) 1845 times than e-

222. Direction of current is1) Same as e- 2) Opposite to e-

3) Perpendicular to direction of e- 4) constant

223. When a glass rod is rubbed with silk, the glass rod gives up electrons and becomes1) Positive charge 2) Negative charge3) No charge 4) None224. The larger value of resistance supports1) More current 2) Less current3) No effect 4) constant

225.Factors affecting the resistance value is1) Area 2) Length3) Temperature 4) All

226. The unit of resistivity is1) Ohm-metre 2) Ohm3) Ohmmeter-1 4) None

227. The Ammeter is always connected :-1) in series 2) in parallel3) Anyway 4) None

228. The value of Resistance whole colours are Red, Red and Red is1) 2k Ω 2) 2)2k Ω 3) 22k Ω 4) 220

229. Tolerance for silver is1) +5% 2) +10%3) + 20% 4) +25%

230. The material used for fuse must have1. low melting point and low specific resistance2. low melting point and high specific resistance3. High melting point and low specific resistance4. None

231. Dielectric strength of a material depends on1) Moisture content 2) Thickness3) Temperature 4) All

232. Relative Permitivity of vacuum is1) Zero 2) 8.854x10-6

3) Unity 4) None

233. What will happen to an insulating medium of voltage more than the break town voltage is applied on it1) It will get punchred 2) It will become magnetic3) It will melt 4) It molecular structure will change

234. 4 capacitor of 5 μF each are connected in parallel their equivalent capacitance will be

1) 20 μF 2) 10μF 3) 5μR 4)1)25 μ F

235. Inside the conducting sphere, ___ remains constant1) Electric flux 2) Electric intensity3) Charge 4) Potential

236. The unit of conductivity is1) Ohm 2) Ω-m3) Mho/metre 4) Siemens

237. Lead Acid cell is said to be in good condition if1. It should not be left in discharging condition for long time.2. Level of electrolytes should be 5mm above the top of plates3. Discharging should not be prolonged after the minimum value of the voltage4. All of the above

238. Alkaline Accumulators are1) Ni-Fe Battery 2) Ni-Cd Battery3) Lead-Acid cell 4) Both 1 and 2239. Positive Plate of Lead-Acid cell during discharge1)Pb2SO4 2) PbO2 3) PbSO4 4) Pb

240. Life of lead Acid cell is1) Nearly 1000 charge and discharge2) Nearly 1250 charge and discharge3) Five years at least4) None

241. Specific gravity of lead Acid cell, when it is 50% charged is1) 1.12 2) 1.22 3) 1.16 4) None

242. Active material of Edison cell are1) PbO2,Pb, H2So4 2) Ni(OH)4,Cd, KOH3) Ni(OH)4, Fe, KOH 4) Ni(OH)2, Fe, KOH

243. Average EMF of lead acid cell is1) 2.1V 2) 2.0V 3) 1.8V 4) 1.2V

244. The input of constant voltage charging system of Battery is1) AC 2) DC 3) AC or DC 4) None

245. Secondary cell is1) Charged only 2) Rechargeable 3) None

246. The colour of positive plate of full charged Lead Acid cell is1) Brown 2) Deep chocolate brown3) Slate Grey 4) None

247. Ratting of the cell is1) Amp-hour 2) Watt-hour3) Both 4) None

248. Negative plate of Edison cell is1) Ni(OH)4 2) Ni(OH)2

3) Cd(OH)2 4) Fe(OH)2

249. Sulphation in a lead – Acid Battery occurs due to1) Trickle charging 2) Incomplete charging3) Heavy discharging 4) Fast charging

250. Whenever a magnet is quickly brought towards an open circuited stationary coil1) A current is induced in it2) Work has to be done3) EMF is induced in it.4) Power is spent.

251. The emf induced in a coil depends on1) the number of its turns2) the change of flux linked with it.3) the time taken to change the flux4) all of the above

252. An emf is induced in the coil whenever flux through it1) is decreased 2) is increased3) is abruptly reduced to zero 4) all of the above253. The direction of the induced emf in a coil may be found with the help of1) Faraday’s law 2) Lenz’s law3) Fleming’s left hand rule 4) Steinmetz law

254. The dynamically induced emf in a conductor does not depend on1) flux density 2) its active length3) its conductivity 4) its velocity

255. The self-induction of a coil is also called its _____ inertia1) Electromagnetic 2) Magnetic3) Both 4) None

256. The coefficient of magnetic coupling between two circuits can have a maximum value of ________1) UNITY 2) ZERO3) TWO 4) NONE

257. Induced emf can be either mutually induced or statically induced1) TRUE 2) FALSE

258. The inductance and number of turn of the coil is related with the formula1) L α N 2) L α N2 3) L = N 4) L= N

259. The Voltage induced in the primary winding of a transformer due to current flowing through it is known as 1) EMF 2) Counter EMF3) MMF 4) Lenz’s law

260. The magnetic property of a coil of wire which causes it to induce an opposite emf within the same circuit is called1) Mutual Inductance 2) Self Induction3) Permeability 4) Retentivity

261. In transformer following principle is/are involved:-1) Conduction 2) Self induction3) Mutual Induction 4) Both 2 & 3

262. In a step up transformer if input power and output power are same then :-1) current in primary = current in secondary2) current in primary > current in secondary3)current in primary < current in secondary4) Voltage in primary > Voltage in secondary

263. The burden of current transformer is expressed in terms of :-1. Secondary winding current2. VA rating of transformer3. Voltage, current and power factor of secondary winding4. None of the above

264. The impedance ratio of transformer is defined by the Relation :-

1) Ns/Np = (Zs/Zp) 2)Ns/Np= (Zs/Zp)2

3) Ns/Np = (Zp/Zs) 4) None

265. In a D’Arsonval galvanometer, an iron core is usually used between the permanent magnet pole faces. This is used so that:1. Flux density in the air gap becomes high thereby a large deflecting torque is produced2. The effect of stray magnetic fields is reduced3. Moment of inertia at moving parts becomes smaller4. None

266. Sometimes, the D’ Arsonval Galvanometer do not use ferromagnetic cores between poles of the permanent magnet. In this case :-1. The flux density becomes smaller resulting in low deflecting torque.2. The dimensions of the moving coil can be made smaller thereby reducing the moment of inertia3. The magnetic field may not be resulting in a non-uniform scale even it spring control is used4. All of the above

267. A vibration galvanometer is tuned1. by changing the length and tension of vibration coil2. by attaching weight to the vibrating coil3. by changing its damping constant4. All of the above

268. In a series type ohmmeter the zero adjustment should be done1. by changing the value of series resistance2. by changing the value of shunt resistance connected across the meter movement3. by changing the both series as well as shunt resistance4. by changing the battery voltage

269. A meggar is used for measurement of1) low valued resistance2) Medium valued resistance3) High valued resistance, particularly insulation resistance4) All of the above

270. The controlling torque in a meggar is provided by1) Springs2) Weight attached to the moving system3) Does not need any controlling torque4) None of the above

271. Thermocouple instruments can be used for a frequency range1) Up to 100 Hz 2) Upto5000Hz3) Up to 1MHz 4) 50 MHz and above

272. Voltmeter measures1) Voltage 2) EMF3) Terminal potential 4) All of the above

273. An Electrostatic voltmeter draws a small value of current on d.c.1. Under steady state condition respective of the applied voltage2. When switched ON irrespective of the applied voltage3. When measuring low voltages4. When measuring high voltages

274. The scale of D’Arsonval metres are :1) cramped at the beginning 2) cramped at the end3) Uniform 4) Non uniform

275. Ohmmeter is used to measure1) Insulation Resistance 2) Circuit resistance3) Continuity of the circuit 4) Both 2 and 3

276. A meter is said to be more sensitive when for full scale deflection :1) It takes less current 2)It takes more current3) It requires a multiplier or a shunt 4) None

277. In a megger the controlling torque is provided :1) Coil springs 2) Current flow in the control coil3) Eddy current 4) Mechanical control method

278. Aircraft DC generator is a :1) Compound generator 2) Series generator3) Shunt generator 4) Either 1 or 3

279. For AC generators having high field current;1)Series generator is used2)Vibrating contact regulator is used3) Carbon pile regulator is used4) Compensating winding is used in regulator

280. In a type of DC generator, when load is increased, voltage increases and when the load is decreased, voltage also decreases, the generator can be 1) Shunt generator2) Differential compound generator3) Compound generator4) Series generator

281. The direction of current flow in a generator is determined by :1) Left hand rule of generator 2) Faraday’s Law3) Lenz’s law 4) Grip rule

282. The armature conductors of a 6 pole lap wound dc generator are divided into, ______ parallel paths1) 2 2) 3 3) 6 4) 4

283. In a long shunt compound wound generator, the shunt field is connected in parallel with1. Armature2. Series field3. Parallel combination of armature and series field4. Series combination of armature and series field

284. The overall efficiency of a dc shunt generator is maximum when its variable loss equal ________ loss.1) Stray 2) Iron 3) Constant 4) Mechanical

285. In a d.c. generator, the main function of compensating windings is to1. Assist in commutation2. Reduce demagnetising effect of Armature reaction3. Reduce distorting effect of armature reaction4. Eliminate reactance voltage

286. The O.C.C of a d.c. generator is also called its ________ characteristics1) Internal 2) Magnetic3) External 4) Performance

287. The line representing the critical resistance of a dc generator _________ its O.C.C1) intersect 2) does not intersect3) just touches 4) runs parallel to

288. The __________ dc generator has the poorest voltage regulation1) Over-compound 2) compound3) Shunt 4) Series

289. Which of the following generator provides approximately constant voltage from no-load to full load1) Series 2) Shunt 3) compound 4) Over compound

290. The armature torque of a dc motor is a function of its1) pole flux 2) Armature current3) Speed 4) Both 1 and 2

291. A d.c. series motor is best suited for driving1) Latches 2) Heavy machine tools3) Cranes and hoists 4) Shears and punches

292. The speed of a dc motor can be controlled by varying1) its flux 2)Armature circuit resistance3) Applied voltage 4) All of the above

293. The level of compounding in a cumulatively-compound d.c. Generator is usually adjusted by:1) alternating series field current2) changing shunt field current3) connecting it long-shunt4) connecting it short – shunt

294. An electric motor is used for1. Generating power2. Changing mechanical energy to electrical3. changing electrical energy to mechanical4. increasing the energy put into it

295. Capacitor is used to1) block AC 2) block DC3) Both 4) none of the above

296. Four inductor of 2μH is connected in series is the equivalent inductance1) 2μ h 2) ½ μH 3) 8μH 4) None

297. Capacitive reactance Xc is measured by relation1) Xc = ½ πf C 2) Xc=2 πf C3) Xc= 1/2 π C 4) None

298. Capacitors with solid dielectric materials are used because1. they give a reduce dielectric loss2. they are smaller is size as compared to air capacitor3. they have lower capacitance value as compared to air capacitor4. None of the above

299. Which one of the following is passive component1) Resistor 2) Capacitor3) Inductor 4) All of the above

302. An electric current is 1) random movement of electrons in a conductor.2) movement of free electrons predominately in one direction.3) pressure difference between two poles.4) the power that causes drift of electrons.

303. Ampere- second could be the unit of :-1) e.m.f. 2) charge.3) power 4) energy

304. The minimum requirements for causing flow of current are:-1) a voltage source, a resistor and a switch.2) a voltage source & a conductor.3) a power source and a bulb4) a voltage source, a conductor, an ammeter and a switch.

305. Pure metals generally have :-1) high conductivity and low temperature coefficient.2) high conductivity and large temperature coefficient.3) low conductivity and zero temperature coefficient.4) low conductivity and high temperature coefficient.

306. With the rise in temperature, the temperature coefficient of resistance :-1) remains unaffected 2) increases.3) decreases. 4) none of these.

307. Temperature coefficient of resistance is defined as:-1) increase in resistance per ohm per degree C2) increase in resistance per degree C3) decrease in resistance per ohm per degree C4) the ratio of decrease in resistance per degree C to the resistance at 0 degree C

308. Which of the following quantities are the same in all parts of a series circuit?1) voltage 2) power.3) current. 4) resistance.

307. Two resistors R1 & R2 give combined resistance of 4)5 ohm when in series and 1 ohm when parallel the resistances are1) 2 ohms & 2.5 ohms 2) 1 ohm & 3.5 ohms3) 1.5 ohms & 3 ohms 4) 4 ohms & 0.5 ohms

308. The ratio of resistances of a 100 Watt, 220 V lamp to that of a 100 Watt, 110 V lamp will be, at the respective voltages1) 4:1 2) 2:1 3) 1:2 4) 1:4

309. A 200 W, 230 V lamp is connected across 115 V supply. The lamp will draw power1) slightly more than 50 watts2) slightly less than 50 watts3) exactly 100 watts4) exactly 50 watts

310. A permeable substance is one1) through which the magnetic lines of force can pass very easily2) which is a strong magnet3) which is a bad conductor4) none of these

311. Soft magnetic materials have 1) high permeability & low coercive force2) low permeability & high coercive force

3) high residual magnetism4) low resistivity

312. When a piece of iron is placed in a magnetic field1) there will be no effect on the magnetic field2) the magnetic lines of force will bend away from the piece3) the magnetic lines of force will bend away from their usual paths so as to pass through the piece4) none of these

313. The magnitude of force acting on a current carrying conductor placed in a magnetic field is independent of1) flux density2) length of conductor3) cross-sectional area of conductor4) current flowing through the conductor

314. The field at any point on the axis of a current carrying coil will be1) perpendicular to the axis2) parallel to the axis3) at an angle of 45 degree with the axis4) zero

315. The property of a material which opposes the production of magnetic flux in it is known as1) mmf 2) reluctance 3) permeance 4) permittivity

316. The magnitude of induced emf in a conductor depends on1) amount of flux cut2) amount of flux linkage3) rate of change of flux linkage4) flux density of magnetic field

317. The principle of dynamically induced e.m.f is utilized in a1) choke 2) transformer3) generator 4) battery

318. A coil with a certain number of turns has a specified time constant. If the number of turns is doubled, its time constant would1) remain unaffected 2) becomes doubled3) becomes one fourth 4) get halved

319. In a step up transformer, the power output is same as primary input power neglecting the losses, but 1) current is increased in secondary2) current increases & voltage decreases in secondary3) current decreases & voltage increases in secondary4) current & voltage both increase in secondary

321. The amount of current required to produce a full scale deflection of the indicating needle is known as1) stability of the instrument2) sensitivity of the instrument3) selectivity of the instrument

4) none of these

322. Thermal circuit breakers 1) can not be reset until the temperature has returned to normal2) it can be reset before the temperature reaches normal3) can be reset at any time4) none of these is correct

323. A resistor coloured red as per the body end dot system is of1) 33000 ohms 2) 3300 ohms3) 22000 ohms 4) 2200 ohms

324. During flight, when more power is needed the generator voltage will1) Remain at a constant value, however the current flow will increase2) Automatically decrease because of the greater current flow 3) Remains at a constant value, the current will also remain at a constant value 4) Increase at a steady value in order to restrict the current flow

325. All resetable circuit breakers1) Should open the circuit irrespective of the position of the operating control when overload exists2) Should open the circuit irrespective of the position of the operating control when a circuit fault exists3) Are referred to as trip-free circuit-free circuit breakers4) All of the above

326. Circuit breakers are located 1) Generally far from the power source 2) Close to the power source3) At any location compatible to the particular unit 4) So as not to be exposed to heat of any kind

327. Generator inter poles 1) Improve generator output 2) Prolong the life of the brushes & commutator3) Reduces radio interference4) All of the above

328. Many of the larger transport a/c have been equipped with AC electrical system. The reason is 1) Easier to install 2) Less maintenance required3) More efficient 4) All of the above

329. A lead-aid battery with 12 cells connected in series (no-load voltage=2)1 volts per cell ) furnishes 10 amperes to a load of 2 ohms resistance. The internal resistance of the battery in this instance is 1) 0.52 2) 2.52 3) 5 4) 0.25

330. If electrolyte from a lead-acid battery is spilled in the battery compartment, which procedure should be followed?1) Apply boric acid solution to the affected area followed by a water rinse2) Rinse the affected area thoroughly with clean water 3) Apply sodium bicarbonate soul to the affected area followed by a water rinse.4) None of these

331. If residual magnetism of a shunt generator is destroyed accidentally, it may be restored by connecting its shunt field:-1)to earth 2)to an a.c. source3)in reverse 4)to a d.c. source

332. Transformer cores are laminated in order to1)simplify its construction 2)minimise eddy current loss 3)reduce cost 4)reduce hysterisis loss

333. The measure of how well the flux of the primary is coupled into the secondaryis called:-1)mutual inductance 2)self-inductance 3) coefficient of coupling 4) coefficient of excitation

334. The speed of an induction motor put in aircraft, with 4 poles and 5% slip is 1)12000 rpm 2)24000 rpm3)11400 rpm 4)22800 rpm

335. The speed of rotor of a synchronous motor, with 4-poles, in aircraft1)12000 rpm 2)24000 rpm3)11400 rpm 4)22800 rpm

336. In order to synchronize two or more alternators, they should have 1)same phase -sequence 2)same frequencies3)same voltages 4)all of these

337. A voltage drop is 100 volt across a 100 ohms resistance delivers1)10,000 watts 2)1000 watts3)100 watts 4)10 ampere

338. Time constant of a RC circuit is:-1)R x C seconds 2)R / C seconds3)C / R seconds 4)R + C seconds

339. Number of alternations in 400 Hz a.c. is 1)200 2)400 3)600 4)800

340. If electrolyte from a lead-acid battery is spilled in the battery compartment, which procedure should be followed?1) Apply boric acid solution to the affected area followed by a water rinse2) Rinse the affected area thoroughly with clean water

3) Apply sodium bicarbonate soul to the affected area followed by a water rinse.4) None of these

341. A fully charged lead acid battery will not freeze until extremely low temperatures are reached because.1) The acid is in the plates, thereby increasing the specific gravity of the solution 2) Most of the acid is in the solution3) Increased internal resistance generates sufficient heat to prevent freezing4) None of these

342. What determines the amount of current which will flow through a battery willable it is being charged by a constant voltage source1) The total plate area of the battery 2) The state of charge of the battery 3) The ampere- hour capacity of the battery 4) None of these

343. The method used to rapidly charge a nickel cadmium battery utilizes 1) Constant current and constant voltage 2) Constant current and varying voltage 3) Constant voltage and varying current 4) None of these

344. The purpose of providing a space underneath the plates in a lead acid battery container is to 1) prevent sediment build up from courting the plates and causing a short circuit2) allow for convection of the electrolyte in order to provide for cooling of the plates3) ensure that the electrolyte quantity ratio to the number of the plates area is adequate4) none of these

345. The servicing and charging of nickel-cadmium and lead acid batteries together in the save service area is likely to result in 1) Normal battery service life2) Increased explosion and / or fire hazard 3) Contamination of both types of batteries4) None of these

346. Nickel-cadmium batteries which are stored for a long period of time of time will show a low liquid level because 1) Electrolyte evaporates through the vents 2) Of current package form individual cells 3) Electrolyte becomes absorbed into the plates 4) None of these

347. What may result it water is added to nickel cadmium battery when it is not fully charged ?1) Excessive electrolyte deletion2) Excessive spewing is likely to occur during the charging cycle3) No adverse effects since water may be added any time 4) None of these

348. In nickel cadmium battery, a rise in cell-temperature1) Causes an increase in internal resistance 2) Causes a decrease in internal resistance 3) Increases cell voltage4) Has no effect

349. When a charging current is applied to a nickel-cadmium battery, the cells gas only1) Towards the end of the charging cycle 2) When the electrolyte level is low 3) It they are defective 4) None of these

350. Transfer of electrical energy from one conductor to another without the aid of electrical connections1) Is called induction2) Is called air gap transfer 3) Will cause excessive arcing and heat 4) Is impractical

351. Effective value of a sine wave is approximately1)1.414 x Peak Value2)Peak Value / 1)4143)0.636 x Peak Value4)Peak Value / 0.636

352. Of the following, which will oppose any change in current 1)resistance 2)capacitor3)inductor 4)all of these

353. Equivalent resistance, when resistors of 2, 4 and 8 ohms are in parallel1) 14 ohms 2) 7 / 8 ohms3) 8 / 7 ohms 4) 2 ohms

354. The effective voltage of a a.c. sine wave 200 peak-to-peak, is approximately1)70.7 volt 2)141.4 volt3)63.7 volt 4)127.4 volt

355. In delta connection 1)line current =phase current 2)line voltage =phase voltage3)line current <phase current 4)line voltage <phase voltage

356. In Y-connected 3-phase a.c. supply1)line current =1.73 x phase current 2)line voltage =phase voltage 3)line current =phase current4)phase voltage =1.73 x line voltage

357. Dielectric strength of a material depends on 1)thickness 2)temperature3)moisture content 4)all of these

358. The direction of rotation of a single-phase motor can be reversed by1) Reversing connections of both windings2) Reversing connections of starting winding 3) Using a reversing switch4) Reversing supply connections

359. If a single phase induction motor runs slower than normal, the more likely defect is 1) Improper fuses 2) Shorted running winding3) Open starting winding 4) Worn bearing360. The voltage required to rupture the given thickness of a dielectric material for capacitor is termed as1) Dielectric strength2) Dielectric constant 3) Capacity of a capacitor 4) Ability of a conductor to hold the charge

361. When relatively high capacitance is required in a small capacitor, we use 1) Ceramic capacitor 2) Paper capacitor 3) Electrolytic capacitor 4) Mica capacitor

362. A circuit is said to be in resonance when 1) inductive reactance= capacitive reactance 2) inductive reactance >capacitive reactance3) inductive reactance<capacitive reactance4) When both the reactance's are minimum

363. The electrolyte solution in Ni-Cd battery is 1) 70% KOH & 30% distilled water, by weight 2) 30% KOH & 70% distilled water, by weight3) 70% KOH & 30% distilled water, by Volume4) 30% KOH & 70% distilled water, by Volume

364. In a constant current charging system, a battery requires attention at the end of charge to avoid1) Sulphation of battery 2) Spilling of electrolyte3) Evaporation of electrolyte 4) Danger of overheating

365. 66. While measuring the value of resistance, connected in a circuit at least one end of resistance is disconnected in order to avoid1) reading the resistance of series path2) damage of resistance in parallel path3) damage of resistance in series path4) reading the resistance of parallel path

366. In how many ways, 3-identical resistors can be connected?1) 1 2) 2 3) 3 4) 4

367. Iron loss is the combination of 1) Copper and eddy current loss 2) Hysterisis and Eddy current loss 3) Copper & Hysterisis loss4) Copper & Mechanical loss

368. In synchronous motor, damper winding is provided in order to 1) Stabilize rotor motion 2) Suppress rotor oscillations 3) Develop necessary starting torque 4) Both (2) & (3)

369. While running, a synchronous motor is compelled to run at synchronous speed because of

1) Damper winding in its pole faces 2) Magnetic locking between stator & rotor poles 3) Induced e.m.f in rotor field winding by stator flux 4) Compulsion due to Lenz's law

370. The direction of rotation of a Synchronous motor can be reversed by reversing 1) Current to the field winding2) Supply phase sequence 3) Polarity of rotor poles4) None of the above

371. The moving system of an indicating type of electrical instrument is subjected to 1) A deflecting torque2) A controlling torque3) A damping torque4) All of the above

372. The damping force acts on the moving system of an indicating only when it is 1) Moving 2) Stationary 3) Near its full deflection 4) Just starting to move

373. The most efficient form of damping employed in electrical instruments is1) Air friction 2) Fluid friction 3) Eddy currents 4) None of these

374. The meter that is suitable for only direct current measurement is 1) Moving-iron type 2) Permanent magnet type 3) Electrodynamics type 4) Hot wire type

375. Damping torque in an indicating instrument is always 1) Opposite to deflection torque 2) In the same direction as the controlling torque 3) Opposite to the direction of motion of moving system 4) Opposite to the controlling torque

376. The main purpose of using instrument transformer in a.c. measurements is to 1) Reduce the possibility of shock 2) Extend the range of ac instruments3) Provide higher transformation ratio 4) Eliminate instrument correction

377. The hot wire ammeter1) is used only for d.c. circuits 2) is a high precision instrument 3) is used only for ac circuits 4) reads equally well on d.c. and /or circuit

378. The power loss due to ohmic heating in a transformer is called 1) magnetic loss2) hysteresis loss3) copper loss4) eddy current loss

378. The capacity of a capacitor is dependent on 1) plate area2) thickness of dielectric3) dielectric constant4) all of the above

379. Multimeter may measure1) current in mili-amps2) voltage in volt3) resistance in ohm4) all of the above

380. In a R-L-C series circuit, at a frequency below the resonance value, the circuit’s behaviour is 1) capacitive 2) inductive3) resistive4) none of the above

381. Which will oppose any change in voltage 1) inductor2) capacitor3) resistor4) both (2) and (3)

382. The outer most orbit of an atom of a semi conductor has :1) 4 electrons2) more than 4 electrons 3) less than 4 electrons4) protons

383. The force between two stationary charged particles is _______ force 1) electromotive 2) electrostatic3) magneto motive 4) centripetal

384. Unit of capacitance is :1) micro farad2) farad 3) mho4) both (1) & (2)385. Coulomb per volt is the unit of –1) inductance 2) inductive reactance3) capacitance4) capacitive reactance

386. With the rise in temperature, the opposition offered to current flow in the semi conductor:1) in creases 2) decreases3) remains unaffected 4) can’t predicated

387. Which one is common in all parts of a series circuit ?1) current 2) power3) resistance 4) voltage

388. A voltage drop 200 V across 50 ohm resistance delivers power of 1) 10 KW2) 1 KW3) 0.8 kW4) 0.1 KW

389. Time constant of RC circuit is :1) R X C2) R/C3) C/R4) R + C

390. The area of hysteresis curve is a measure of 1) magnetic flux2) MMF per cycle3) Pemeance 4) Energy loss per cycle

391. Magnetism of a magnet can be destroyed by :1) heating2) inductive action by other field3) hammering4) all of the above

392. The number of positive alternations of aircraft electrical system voltage is equal to :1) 200 2) 4003) 6004) 800

393. The sensitivity of the D’Arsonval meter movement is expressed in terms of 1) ampere2) volt3) either ampere or volt4) neither (1) nor (2)

394. Of the following, which will resist any change in current ?1) inductor2) capacitor3) resistor4) all of the above

395. The effective value (RMS) of a sine wave is nearly1) √2 X Vp2) Vp X 1/√23) 0.636 X Vp4) Vp / 0.636 where Vp – peak value

396. Power factor is the ratio of 1) active power to reactive power2) real power to apparent power3) reactive power to VA power4) actual power + VAR power

397. The equivalent capacitance value, when three capacitor having same value, are connected in series, is :

1) 75 MF2) 25 MF3) one third of each value4) 3 times the value of the capacitor

398. The value of resistance between two vertices, when three equal resistance are connected in delta form, is 1) 1/3 x X2) 2/3 x X3) 3/2 x X4) 1/4 x X where X - > the value of each resistor

399. The colour of the fourth band of the carbon resistor indicates its : 1) current rating 2) voltage rating3) ohmic value4) tolerance

400. The device which converts one form of energy into other form is called 1) motor2) generator3) transducer4) transformer and battery

401. The direction of the rotation of dc. Motor can be reversed by :1) reversing the field current2) reversing armature current3) either (1) or (2) 4) reversing the input terminals

402. The commutator segments are insulated from one other by 1) thin sheet of mica2) using riser3) hard drawn copper4) pig tail

403. Battery charger may have generally 1) dc generator/ac generator as source 2) transformer primary multi tapped3) transformer with rectifier unit4) selector switch only

404. A device which converts ac into dc and vice versa is :1) Inverter2) rectifier3) alternator4) commutator

405. A d.c. generator consists of :1) field frame assembly2) armature assembly3) commutator and brush assembly4) all of the above

406. Degree of compounding means the effect of 1) series field on terminal voltage2) terminal voltage on series field3) generated voltage on terminal voltage

4) shunt field on series field

407. If terminal voltage is equal to full load voltage, generator is called :5) flat compound6) differentially compound7) cumulatively compound 8) either (2) or (3)

408. In compound wound generators _____ field coil is of ____ conductor with ____ turns.1) series, thick, a few2) series, thin, a few3) series, thin, many4) series, thin, many

411. The effect of armature reaction may result in 1) pitted commutator surface2) enough wear on brushes3) reduction in output voltage4) all of the above

412. The _____ motor is not started without mechanical load :1) d.c. series2) induction3) shaded pole4) capacitor start

413. For a d.c. motor which of the following is wrong 1) copper losses in field and armature winding2) hysteresis losses in armature core3) hysteresis losses in electro magnet4) eddy current losses in magnetic core

414. The part of a d.c. motor which change the current flow from one wire to another is :1) Yoke 2) armature3) brushes 4) commutator

415. In aircraft, frequency of a.c. supply is :1) 800 Hz 2) 400 Hz 3) 200 Hz 4) 100 Hz

416. For the given shape of coil, the inductance value depends on 1) number of turns1) cross sectional area2) type of core3) all of the above

417. The starting winding of single phase induction motor is placed in :1) rotor 2) stator3) armature 4) field

418. The single phase motor is :1) Inherently not self starting2) Is self starting3) Requires only one winding4) Can rotate in one direction only

419. In reed type frequency meter, the reed with natural frequency of 200 cps is marked :1) 100 cycles 2) 200 cycles

3) 150 cycles 4) 400 cycles

421. In case of discharge of lead acid battery1) formation of PbSO4 on both plates occurs2) sp. gravity of electrolyte increases 3) cell emf. Increases4) colour of positive plates becomes chocolate deep brown

422 In completely charged condition, the cell emf. of lead acid is nearly :1) 2.2V2) 1.5V3) 1.25V4) 1.75V

423 The active component of pb-acid cell is :1) spongy lead2) lead peroxide3) electrolyte4) all of the above

424. The sump jar is used in installation of battery in a/c for the purpose 1) to prevent the corrosion in a/c structure 2) strengthen the electrolyte3) to purify the electrolyte4) to make the electrolyte thick

425. ____ is one of the factor of thermal run away of ni/cd (Nickel / Cadmium) cell1) damaged layer of cell phane material2) exothermic reactions at electrodes (plates)3) 30% dilute KoH by volume4) both (1) and (2)

426. Which of the following is correct for Ni/cd battery 1) its initial cost is relatively high1) current delivering capacity less2) it can not be discharged to zero voltage level3) for same capacity of pb acid, its weight is high

427 At resonance, for the tank circuit, ________ is maximum 1) Impedance1) current2) both (1) and (2)3) neither (1) nor (2)

428 In case of Ni/cd battery, during discharge _____ remains unchanged1) voltage of cell 1) sp. gravity 2) amount of active material at cathodes3) amount of active material at +ve plates

429 Horizontal ribs in Pb-acid cells1) provide the cavity for electrolyte1) provide the cavity for fallen material2) enhance the rate of reaction3) enhance the delivering rate of current

430 During the installation of battery in a/c, _____ terminal is connected first and in order to____:1) positive, complete the circuit1) negative, complete the circuit2) positive, avoid the accidental short3) negative, avoid the accidental short

431 _______ ribs of battery in order to circulate the electrolyte and _____ ribs in order to accumulate the fallen material are made :1) horizontal, vertical1) horizontal, horizontal2) vertical, horizontal3) vertical, vertical

432 When electrolyte is prepared :1) chemical should be added drop wise1) water should be added2) either (1) or (2)3) neither (1) nor (2)

433 In case of Ni/cd cell or battery, in order to maintain the electrolyte level1) mineral water can be added1) tap water can be added during any state of

charge2) distilled water should be added after 2hrs.

later than completion of full charge3) distilled water should also be added without

confirmation of its full charge

434 What do you observe when Ni/cd cell is kept on normal load ?1) decrease in electrolyte level1) significant reduction in OCV2) fall in CCV3) both (1) and (3)

435 What precautions should a technician take during storage of battery expected to used shortly1) battery should be always charged1) storage house should be well vertillated 2) detrimental material and open flame should

not be in vicinity of batteries3) all of the above

436. Which test is done with a/c battery ?1) electrical leakage test 2) electrolyte leak test3) capacity test 4) all of the above

437. The capacitor can be used 1) to produce the starting torque 2) to filter the wanted signal3) to enhance the voltage induced in magneto4) all of the above

438. The current through the capacitor leads its voltage drop by an angle of :

1) 90 degree2) 60 degree3) 30 degree4) 45 degree

439. In elementary d.c. generator, if no of coil is increased

1) induced emf. will increase2) no. of ripple frequency will increase, resulting

in steady dc3) ripple will decrease4) both (2) and (3)

440. Which of the following facts related to elementary d.c. generator is incorrect?

1) during the rotation, for instant, when coil’s plane remains along MNA induced emf is minimum

2) in above case, when coil’s plane is along MA, induced emf is maximum

3) direction of current flow in coil is given by lenz’s law

4) direction of polarity of induced emf is given by Fleming left hand rule

441. The operating principle of generator is based on 1) faraday’s law of electrolysis1) faraday’s law of electromagnetic induction2) lez’s law3) child’s law

443. In electrical measuring instrument (D’Arsonval meter), most effective damping torque is given by 1) eddy current1) fluid friction2) pneumatic friction3) all of the above

444. Damping torque is essential in order to :1) bring the pointer after less no. of oscillation 1) to see the reading easily and get-accurate

value2) both (1) and (2)3) none of the above

445. Which of the following has/have linear (even) scale1) PMMC,1) Dynamometer wattmeter2) Moving iron ammeter3) Both (1) and (2)

446. Which of the following measure ac current only1) PMMC1) Dynamometer ammeter2) Moving coil ammeter3) Induction ammeter

447. Energy meter has1) scale1) pointer2) gear train3) both (1) and (2)

448. Which of following is correct ?When θ- deflection , I – Current, V – Voltage, W – Watt.1) θ α I for PMMC

2) θ α V for PMMC3) θ α W for dynamometer watt meter, 4) all of the above449. The method to obtain the residual magnetism in self excited, in d.c. generator is known as 1) field flashing1) commutation2) excitation3) rectification

450. Reason behind large movement of pointer (about 270 degree) over the scale of D’Arsonval meter 1) field is radial1) deflection proportional to electrical quantity2) eddy current damping 3) both (1) and (2)

451. In a step up transformer, the power output is same as primary power neglecting the losses, but ______ in secondary 1) current increases 1) current increases but voltage decreases2) current decreases and voltage increases3) current and voltage both increase

452. In practical transformer, the coefficient of coupling is :1) less than 1 2) more than 13) equal to 1 4) equal to nearly 100

453. Turn ratio of transformer is equal to ratio of 1) θ2 & θ11) V2 & V12) E2 & E13) E1 & E2

When θ (θ1, θ2) – flux, V (V1, V2) – Terminal voltage, E (E1, E2) – induced in winding

454. The induced emf. In primary and secondary of a transformer are1) equal in magnitude2) in same phase3) 180 degree out of phase with applied signal 4) both (2) and (3) are correct

455 The rotational (frictional) losses do not occur in1) Transformer 2) dc-generator3) Static inverter 4) both 1 & 3

456. The D’Arsonval meter movement may be used to measure1) current only2) voltage only3) resistance only4) current, voltage and resistance

457. The shunting effect occurs in ______ generally1) ammeter 2) voltmeter3) wattmeter 4) none of the above

458. In the circuit given below

1) I (R1+R2+R3) – E2 + E1 = 02) I (R1+R2+R3) + E1 - E2 = 03) I (R1+R2+R3) + E1 + E2 = 04) I (R1+R2+R3) – E1 - E2 = 0

459. Kirchoff’s laws are applicable to1) ac only 2) dc only3) both (1) and (2) 4) none of the above460. According to Ohm’s law for resistor1) V α I2) V=RI3) V=KIn

4) Both (1) and (2) where n=1/2

461. The retentivity of magnetic material means1) residual magnetism2) ability to keep residual magnetism3) ability to remove the residual magnetism4) ability to get magnetism

462. The soft iron piece is used as electromagnet because it has ____ retentivity and _____ permeability1) low, high2) high, low3) low, low4) high, high

463. In self excited dc-generator, electromagnet instead of permanent magnet is used for necessary field1) to change the field strength as per

requirement2) because with time strength of p. magnet

decreases3) because its size is less4) all of the above

464. In generator, induced emf depends on1) no of turns2) field strength (¢)3) speed of armature4) all of the above

465. Very high insulation resistance of electric cable shall be measured by1) high range ohmmeter2) meggar3) ammeter4) both (1) and (2) are correct

466. How can it be determined if a transformer winding has some of its primary turns shorted together?1) the output voltage will be low2) it will not function

3) it will get hot in normal operation4) its input current will be less

467. Aircraft fuse capacity is rated in1) volt2) ohm3) microfarad4) all of the above are incorrect

468. Which of the following is correct?1) an electromechanical s/w with fixed core is

called solenoid2) an electromechanical s/w with movable core is

called relay3) an electromechanical s/w with fixed core is

called relay4) all of the above

469. An instrument that works as ohmmeter, ammeter and voltmeter is known as1) wattmeter2) megger3) frequency meter4) avometer

470. A circuit is said to be resonant when1) XC = XL

2) XC < XL

3) XC > XL

4) XC & XL are minimum

471. The dielectric strength is measured in terms of1) breakdown voltage per unit thickness2) breakdown voltage3) current4) watt

472. Why are the iron cores of most induction coils laminated1) to increase core reluctance2) to increase core permeability3) to reduce the effect of eddy current4) all of the above are wrong

473. Most of circuit breaker used in a/c is1) resettable2) non resettable3) based on principle of bimetallic4) thermally operated

474. A/c circuit breakers1) can be used as controlling device sometimes2) can be used as protective device3) are mostly thermally operated4) both (1) and (2)

475. The range of voltmeter and ammeter can be increased by _____ and _____ respectively1) shunt, multiplier2) shunt, shunt3) multiplier, shunt4) multiplier, multiplier

476. Which of the following is correct?1) voltmeter may be connected across source2) ammeter may be connected across source3) ammeter is connected in parallel4) voltmeter is connected in series

477. ____/ __ is the symbol of1) SPDT 2) SPST3) DPST 4) DPDT478. In dc motors1) net emf = applied voltage – counter emf2) net emf = counter emf – applied emf3) net emf = counter emf4) net emf = applied voltage

479. The speed of series wound dc motors can be changed1) by field diverter above normal value2) by field diverter below normal value3) either (1) and (2)4) none of the above

480. Derating factor is a ____ in order to establish _1) multiplier, capacity of s/w2) multiplier, suitable voltage to the circuit3) multiplier, current value for CB4) multiplier, current rating of fuse

481 . The example of intermitted relay switch is ___1) battery relay switch2) starter relay switch 3) both (1) and (2)4) neither (1) nor (2)

482 The sole purpose of a commutator in dc generator is to1) increase output voltage2) reduce sparking at brushes3) provide consistency in output4) convert ac into dc

483. High frequency voltage is used in a/c in order to1) reduce the weight of motor2) reduce the speed of motor3) increase the efficiency of motor4) all of the above

484. Which of the following is incorrect?1) current transformer (CT) is accurate current

ratio transformer2) CT is step up transformer3) When in operation its secondary should not be

open4) CT may be used to measure voltage with low

range instrument

485. Basic difference between CT and PT will be that1) PT is ratio transformer2) PT is ac operated device3) PT is very low power instrument transformer4) PT is step down transformer

486. In auto transformer1) both windings are electrically isolated2) power is transferred by induction only3) there is saving of copper material4) it is not power transformer

487. Power is given by _____ in 3-phase alternator1) √3 VL IL 2) √3 VP IP3) √3 VP IL 4) √3 VL IP

488. If after starting, one connection to 3-phase induction motor is accidentally broken1) motor will always continue to rotate2) motor will continue to rotate if load on motor

is less than 1/3rd of full load3) motor will continue to rotate in case of full

load only4) motor will never rotate

489. Which of the motors is not self starting1) two phase induction motor2) series wound dc-motor3) 3 phase induction motor4) 1 – phase induction motor

490. If the speed of induction motor is predicted to be synchronous1) relative speed of rotor w.r.t field is zero2) % slip is zero3) net torque is zero4) all of the above are correct

491. The direction of ______ motor can not be reversed1) dc series2) 3 - phase induction3) capacitor start induction4) shaded pole induction

492. Which one is incorrect ? 1) in 3 phase star (λ) connected alternator line

voltage = √3 x phase voltage 2) in 3 phase induction motor, three windings are

120 degree electrically displaced3) 3-phase motor or multiphase motor, there is

synchronous field4) TR-unit converts dc into ac

493. Which of motors has the highest starting torque for same power output1) series dc motor2) cumulatively comp motor3) shunt wound dc motor 4) differentially comp motor

494. Series dc motors are used in a/c1) as engine starter2) for raising or lowering landing gear3) for cow flaps4) all of the above

495. When cell is loaded, the terminal voltage, Vt1) is less than emf of cell by ‘Ir’ drop2) is equal to cell’s emf3) is greater than emf by ‘Ir’ drop4) all of the above are correct

496. Fact related to primary cell is that1) cell can not be recharged satisfactorily2) negative plates of cell does not deteriorates

when on load3) material (active) does not go into electrolyte4) positive plates of cell deteriorates effectively

497. Fact relating to secondary cell is that1) active material does not go into solution2) it can be recharged and discharged many

times before complete deterioration3) active material undergoes chemical changes

during charging and discharging4) all of the above are correct

498. Sulphation in cell means1) to charge the cell at slow rate2) to discharge it at slow rate3) layer of active material becomes hard and

useless4) boiling of electrolyte

499. One more negative plate (in Pb acid cell) than +ve plates is used in order to1) prevent +ve plate from warping2) increase the cell potential3) increase the cell capacity4) decrease the cell’s internal resistance

500. Cells are rated as1) AH2) voltage3) watt4) both (1) and (2)

501. Factors affecting the capacity of cell are1) rate of discharge or recharge2) no of plates (area of plates)3) density of electrolyte and active material mass4) all of the above

502. Ni / Cad cell is advantageous over Pb-acid cell from ______ view point1) low maintenance cost and long service life2) short recharge time and good reliability3) excellent reliability and good starting ability4) all of the above

503. Your observations relating to Ni / Cad cell may be1) release of O2 from –ve plates and absorption

of O2 by +ve plates during charging2) formation of gas (mixture of H2 & O2) towards

end of charging process3) sp. gravity unchanged 4) all of the above504. Alkaline solution is neutralized by using1) vinegar 2) lemon juice3) boric acid 4) any one of the above

505. Which one is the polar capacitor?1) Oil 2) mica3) Electrolytic 4) paper

506. A capacitor may be used

1) to reduce the ripple2) to store the charge3) to filter the frequency signal4) all of the above

507. In one time constant, capacitor takes the charge up to ___ % of its full charge1) 63.2 2) 36.73) 20.6 4) 80.2

508. How many time constants needed by capacitor to changed upto 99.8% requires1) 062) 043) 074) 03

509. The working voltage of capacitor depends on1) type of dielectric2) thickness of dielectric3) frequency of voltage4) all of the above

510.

In the above figure, value of resistance across AB is1) 1 ohm2) 2 ohms3) 5 ohms4) 4 ohms

511. Relation of actual power, reactive power and apparent power should be1) app. Power2 = real power 2 + reactive power 2

2) app. Power = real power + reactive power3) app. Power = real power – reactive power4) app. Power = real power x reactive power

512. Power factor is the ratio of _____ to _____1) actual power, apparent power2) resistance, impedance3) both (1) and (2) are correct4) reactive power, apparent power

513. The scale of _______ meter is linear and even1) D’Arsonval meter movement2) Dynamometer ammeter3) Moving iron is mount as voltmeter4) Energy meter

514. The adverse effect of armature reaction is minimized by1) shifting the brushes2) placing the inter poles3) placing the compoles4) all of the above

515. The effect of current in armature causes

1) reduction in effective field strength2) distortion in field flux3) sparks between commutator and brushes4) all of the above

516. Which of the following is incorrect1) in 3 phase synchronous motor, field is rotating2) in 3 phase induction motor, field is stationary

and pulsating3) synchronous motor is inherently not self

starting4) synchronous motor can be made self starting517. Coercivity means ability1) to annul the residual magnetism2) to magnetise the core up to point of saturation3) to restore magnetism4) both (2) and (3)518. Induction type instruments are used to measure

1) ac current2) ac voltage3) ac power4) all of the above

519. When load on induction motor is decreased1) speed increases2) slip decreases3) relative speed decreases4) all of the above

520. Indication of battery Ni / Cad fully charged is given by1) excessive formation of gases2) significant change in sp-gravity3) significant change in OCV4) reduction in electrolyte level