ELECTRICAL SYSTEM-II A/C ELECTRICAL SYSTEM
1. Suppose you suddenly come across a colleague who is stuck to live bus-bars in a sub-station. Your first action
would be to: (Ref. BL Theraja)
a. switch off the supply b. put him away from the bus-bars c. immediately call for medical assistance d. start artificial breathing straightaway
2. The centripetal force necessary to keep electrons rotating the elliptical orbits round the nucleus is supplied by the force of attraction between their charges are given by (Ref. BL Theraja)
a. coulomb‟s laws b. faraday‟s laws
c. Fleming‟s law d. none of the above
3. The purpose of carbon contact in attracted-core, heavy duty relay: (Ref. EHJ Pallet, 108) a. to limit the current in relay coil
b. to absorb initial heavy current and thereby reduce arcing to a minimum before positive connection with main contacts is made
c. to compensate for loss of spring d. all the above are correct
4. The RMS value of alternating current is: (Ref. EHJ Pallet, 33)
a. sum of square of individual component of currents
b. sum of square of individual components of currents divided by no. of individual components
c. during a half cycle, squaring the value and taking their mean value and then taking the square root d. none of the above
5. A tumbler switch is also called: (Ref. AC 65 – 9A)
a. micro switch b. toggle switch
c. push switch d. none of the above
6. The performance of rectifier depend on: (Ref. Grob., 812)
a. maximum temperature of plate b. maximum reverse voltage c. minimum voltage d. both a & c are correct
7. Which switch is not having moving parts: (Ref. TK Eismin, 259)
a. mercury b. thermal
c. proximity d. rotary
8. Which is not thermally affected by temperature: (Ref. AC 65 – 9A)
a. fuse b. CB c. limiting resistor d. thermistor
9. The effect of change in frequency will change: (Ref. BL Theraja – Ed 1991, 578)
a. hysteresis loss b. eddy current loss
10. A series LCR is connected to 20V AC supply. The value of resistance is 8 ohms, inductive reactance of coil is 18ohms and capacitive reactance of capacitor is 12 ohms. How much is current flow in the circuit:
(Ref. EHJ Pallet, 202)
a. 2 amps b. 10 amps c. 5 amps d. 1 amp.
11. A LCR circuit is connected across 200V, 50 Hz AC supply, value of R is 6 ohms, inductive reactance is 8 ohms and capacitive reactance is 16 ohms. Calculate the voltage drop across the resistance: (Ref. EHJ Pallet, 202)
a. 200/30 volts b. 200/2 volts
c. 120 volts d. none of the above
12. Which of the relay have very high sensitively: (Ref. EHJ Pallet, 108)
a. slugged relay b. polarized relay
c. heavy duty relay d. none of the above
13.What is the resistance of wire having same cross sectional area and material when the length is increased by 6
times: (Ref. AC 65 – 9A)
a. two times b. 6 times c. 8 times
14. Temperature compensation capacitor is made of: (Ref. Grob., 420)
a. mica b. chip
c. paper d. ceramic
15. Mark the correct statement for a single loop coil lying parallel to the magnetic field:
(Ref. BL Theraja-Ed 1991, 244) a. flux linked with the coil is minimum b. rate of change of flux linkages is maximum
c. emf induced in the coil is maximum d. all the above
16. When adding a rheostat to a light circuit to control the light intensity, it should be connected in:
(Ref. EHJ Pallet, 153) a. parallel with the light b. series with the light
c. series parallel with the light d. none of the above
17. Paper capacitors are suitable for: (Ref. BL Theraja-Ed 1991, 157) a. short wave work in radio b. smoothing circuits in radio receivers
c. audio frequency stages of radio receivers d. use at radio frequency
18. The delay in establishment of steady current through a coil depends on the value of:
(Ref. BL Theraja – Ed 1991, 242)
a. applied voltage b. self inductance
c. resistance d. both b & c are correct
19. Kirchhoff‟s current law is applicable to: (Ref. BL Theraja, Ed. 1991, 56) a. closed loop b. electronic circuit
c. junction in network d. all the above
20. If the power factor is unity reactive power is: (Ref. BL Theraja, Ed. 1991, 457)
21. Match the correct statement for proximity sensors:
a. proximity sensors are simply induction coil that operate in conjunction with steel targets b. the inductance of a proximity sensor is measured by a electronic control unit
c. no moving contacts to fail, thereby high reliability
d. all are correct (Ref. TK Eismin – 259)
22. to get full wave rectification with the help of only two diodes: (Ref. BL Thareja, Ed. 1991 – 691) a. a bridge configuration is used b. center tapped transformer is required
c. diode connector is required d. none of the above
23. The basic unit of capacitance is: (Ref. EHJ Pallet -195)
a. coloumb b. tesla c. gauss d. farad
24. The sensitivity of a voltmeter can be increased by: FAA-9A, P-329
a. increasing the strength of the permanent magnet b. using lighter weight materials for the moving element c. by using sapphire jewel bearings to support the moving coil d. all of the above
25. The frequency of an eight pole alternator rotating at 1800 rpm is: FAA-9A, P-417
a. 60 Hz b. 90 Hz c. 120 Hz d. 30 Hz
26. Circuit breakers are located: Pallet, P-115
a. generally far from the power source b. close to the power source
c. at any location compatible to the particular unit d. so as not to be exposed to heat of any kind
27. All resistible circuit breakers: Pallet, P-113
a. should open the circuit irrespective of the position of operation control when overload exists b. should open the circuit irrespective of the position of operating control when a circuit fault exists c. are referred to as trip free circuit
d. all of the above
28. The total opposition to alternating current in an AC circuit is known as: Eismin, P-87 a. total resistance b. resistance c. reluctance d. impedance
29.Theopposition offered by a coil to the flow of ac is called:
a. reluctance b. impedance c. inductance d. inductive reactance
30. Soft soldering: CAIP-281
a. is a method of joining metals with fusion of the basis metal
b. is a method of joining metals without intentional fusion of the basic metal
c. as in (b) and is done by the solders having a lower melting point than the metals being joined d. as in (a) and is done by the solders having a higher melting point than the metals being joined
31. In an series RLC circuit: BLT/1991/473
a. current lags behind the voltage if XL>XC b. current lags behind the voltage if XC>XL c. current is in phase with voltage if XL=XC d. all are correct
32. An ac circuit has 4 ohms resistance and 3 ohms reactance: FAA-9A, P-358 a. power factor is 0.8 b. power factor is 1.33
c. impedance is 6 d. impedance is 8
33. In an AC circuit the 5% of max. value of voltage occurs at: BLT/1999/ED/42
a. 45 b. 60 c. 30 d. 90
34. Pallet-100
(i) (ii)
(iii) (iv)
(a) single-pole, double throw (b) double-pole, single-throw
(c) single-pole,single-throw (d) double-pole,double-throw
a. (i) (a) (ii) (b) (iii) (c) (iv) (d) b. (i) (b) (ii) (c) (iii) (d) (iv) (a) c. (i) (c) (ii) (b) (iii) (a) (iv) (d) d. (i) (d) (ii) (a) (iii) (c) (iv) (b)
35. MTCS:
a. current limiters limit the starting current in the starter motor
b. limiting resistor limits the
starting current in the
starter motor
c. HRC fuses limit the starting current in the starter motor d. circuit breakers limit the starting current in the starter motor
36. A white band on the button of a circuit breaker when exposed indicates: Pallet-114 a. circuit breaker is on and functioning properly
b. circuit breaker is drawing less current than the rated value c. circuit breaker is tripped
d. circuit breaker is overheated and must be now switched off
37. Electric charge is measured in: Pallet-195
38. Magnetic flux is measured in: Pallet-195 a. ampere turn b. tesla c. weber d. ampere per meter
39. Gilbert is the unit of: Pallet-196
a. magnetic field b. flux density c. magneto motive force d. reluctance 40. Ampere-turn is the unit of:
a. magneto motive force b. flux density c. reluctance d. magnetic field
41. The opposition to the flux established by the magnetizing force is known as: Pallet-196 a. magneto motive force b. reluctance c. resistance d. impedance
42. The rate of doing work is known as: Pallet-194
a. energy b. potential c. current d. power
43. That part of the impedance which is due to inductance, or both, and which stores energy rather than dissipates
it, is known as: Pallet-195
a. capacitance b. inductance c. both (a) & (b) d. reactance
44. The amount of magnetic flux per square centimeter, over a small area at a point in a magnetic field is known as: Pallet-195 a. magnetic field strength b. magnetic flux density
c. magneto motive force d. permeability
45. A circuit breaker is a device for: Pallet-223
a. protecting an electrical circuit from current overload b. collapsing the primary circuit of a magneto
c. completing a circuit without being affected by current flow d. all of the above
46. The current in a purely capacitive circuit will: Pallet-221
a. lead the applied voltage b. lag the applied voltage c. be in line with the applied voltage d. either (b) or (c)
47. Factors that must be considered in selecting the size of wire are: FAA-15A, P-436 a. I2R b. IR drop c. current carrying ability d. all of the above
48. The voltage drop in the main power cable from aircraft generation source or the battery to bus should not
exceed: FAA-15A, P-436
a. 2% of regulated voltage b. 3% of regulated voltage c. 4% of regulated voltage d. 1% of regulated voltage
49. The max. resistance between ground point of generator/ battery and ground terminal of any electrical device
should not exceed: FAA-15A, P-436
a. 0.005 b. 0.05 3. 0.5 4. 0.0005
50. Push switches are primarily used for those circuits which are required to be operated for: Pallet-101 a. short duration
b. long duration
c. when circuit is to be completed or interrupted momentarily d. both (a) & (c) are correct
51. The impedance of an AC circuit is measured in: Pallet-221
a. kilovolt amperes b. amperes c. ohms d. none of the above
52. The number of circuits which can be completed through the poles of a switch is indicated by the term: Pallet-223
a. pole b. position c. throw d. none
53. In a thermal switch employing steel and invar element actuation of the contacts under increasing temperature
condition is caused by: Pallet-223
a. expansion of the steel element only b. contraction of the invar element only
c. expansion of the steel element causing displacement of the in rear element d. none of the above
54. A soft iron core is placed within the coil of a moving coil instrument because: Pallet-223 a. it provides a solid spindle about which the coil can rotate
b. this ensures an even, radial and intensified magnetic field for the coil to move in c. the inertia of the core will damp out oscillations of the coil
d. none of the above
55. Relays which are slow to operate are known as: Pallet-108
a. slugged relays b. polarized relays c. light duty relays d. extremely light relays
56. Switches which confine the action of toggle and push-button switches are called: Pallet-102 a. rotary switches b. micro switches c. tumbler switches d. rocker-button switches
57. Toggle switches are also known as: Pallet-100
a. rotary switches b. time switches c. tumbler switches d. push switches
58. Mercury switches are used in/for: Pallet-104
a. monitoring pressures b. measuring angle c. delaying the operation d. hastening the operation
59. The principal advantage of proximity switches over micro switches is that: Pallet-106 a. proximity switches are located very near to the circuit component and hence do not require lengthy wires for operation
b. use of relays is eliminated when proximity switches are used hence total components used will be much less c. proximity switches have no moving parts as compared to micro switches
d. proximity switches work on the same principle as solid state devices hence they consume very small amount of power
60. When using an ohmmeter to check the continuity of a generator field coil, the coil should: Pallet-207 a. be removed from the generator housing
b. show high resistance when the meter probes are connected to the terminal of the coil c. show very low resistance if it is a series coil
61. Megger is used for testing : FAA-9A-331 a. ground, continuity tests
b. measuring insulation resistance
c. measuring resistance with a high potential d. all are correct
62. The precaution for using ohm meter are: Pallet-166
a. circuit components to be tested should be isolated b. power source to be removed from circuit
c. both (a) & (b) d. none is correct
63. An ohm meter when connected across a circuit component indicates infinity, it means: FAA-9A-330 a. the circuit has continuity b. the circuit is open
c. the circuit has short circuit d. all of the above are correct
64. Meggar needle normally rests at: FAA-9A-330
a. extreme right b. extreme left
c. middle d. at any place
65. While measuring the value of resistance, connected in a circuit at least one end of resistance is disconnected in order to avoid:
a. reading the resistance of series path b. damage of resistance in parallel path c. damage the resistance in series path d. reading the resistance of parallel path
66. The most efficient form of damping employed in electrical instrument is: FAA-9A-324 a. air friction b. fluid friction c. eddy current d. none of the above
67. The meter that is suitable for only direct current measurement is: BLT/1991/366
a. moving iron type b. permanent magnet type
c. electrodynamometer type d. hot wire type
68. The hot wire ammeter: Eismin-244
a. is used only for DC circuits b. is a higher precision instrument c. is used only for AC circuits d. reads equally well DC and or AC
69. The moving system of an indicating type of electrical instrument is subjected to: BLT/1991/353 a. a deflection torque b. a controlling torque
c. a damping torque d. all of the above
70. Which is not essential for the working of an indicating instrument: BLT/1991/417 a. deflecting torque b. braking torque c. damping torque d. controlling torque 71. If an ammeter is used as a voltmeter, in all probability it will: BLT/1991/418 a. indicate much higher reading b. give extremely low reading
c. indicate no reading at all d. burn out
72. If a moving coil ammeter is used to measure the value of a alternating sinusoidal current having a peak value of 100 A, it will read
73. In a capacitive circuit:
a. a decrease in applied voltage makes a capacitor charge b. a steady value of applied voltage causes discharge
c. an increase in applied voltage makes a capacitor discharge d. an increase in applied voltage makes a capacitor charge 74. In a sine-wave ac circuit with XC and R in series, the: a. phase angle of the circuit is 180 with high series resistance
b. voltage across the capacitance must be 90 out of phase with its charge and discharge current c. voltage across the capacitance has the same phase angle as its charge and discharge current
d. charge and discharge current of the capacitor must be 90 out of phase with the applied voltage
75. In a sine-wave ac circuit with R and C in parallel: a. the voltage across C lags the voltage across R by 90
b. resistive IR is 90 out of phase with IC c. IR and IC are in phase
d. IR and IC are 180 out of phase
76. In a sine-wave ac circuit with a 90 R in series with a 90 XC, the phase angle equals:
a. 30 b. 45 c. 60 d. 90
77. The combined impedance of a 1000 R in parallel with a 1000 XC equals:
a. 500 b. 707 c. 1000 d. 2000
78. With 100 V applied across two series capacitors of 5F each, the voltage across each capacitor will be:
a. 5 V b. 33 1/3 V c. 50 V d. 66 2/3 V
79. In a sine-wave ac circuit with XC and R in series, the a. voltages across R and XC are in phase
b. voltage across R and XC are 180 out of phase
c. voltage across R leads the voltage across XC by 90 d. voltage across R lags the voltage across XC by 90
80. Flight compartment lights include: Eismin, P-256
a. incandescent flood light b. fluorescent flood lights c. dome light and panel lights d. all of the above 81. With higher frequencies, the amount of capacitive reactance:
a. increases b. stays the same c. decreases d. increases only when the voltage increase 82. At the same frequency, larger capacitance results in:
a. more reactance b. the same reactance
c. less reactance d. less reactance if the voltage amplitude decreases 83. Two 1000 XC values in series have a total reactance of:
84. With 50V rms applied across a 100- XC, the rms current in the circuit equals: Grob, P-542
a. 0.5A b. 0.637A c. 0.707A d. 1.414A
85. A capacitor consists of two:
a. conductors separated by an insulator b. insulators separated by a conductor
c. conductors alone d. insulators alone
86. A capacitance of 0.02F equals:
a. 0.02x10-12 F b. 0.02x10-6 F
c. 0.02x106 F d. 2002x1012 F
87. Capacitance increases with:
a. larger plate area and greater distance between plates: b. smaller plate area and less distance between plates c. larger plate area and less distance between plates d. higher values of applied voltage
88. Which of the following statement is correct: Grob, P-522
a. air capacitor have a black band to indicate the outside foil b. mica capacitors are available in capacitance values of 1 to 10F
c. electrolytic capacitors must be connected with the correct polarity d. ceramic capacitors must be connected in the correct polarity
89. Which of the following statement is true: a. alnico is commonly used for electromagnets
b. paper cannot affect magnetic flux because it is not a magnetic material c. iron is generally used for permanent magnets
d. ferrites have lower permeability than air or vacuum 90. Hysteresis losses:
a. are caused by high high-frequency alternating current in a coil with an iron core b. generally increase with direct current in a coil
c. are especially important with permanent magnets that have a steady magnetic field d. cannot be produced in an iron core, because it is a conductor
91. The ac power line voltage of 120 V rms has a peak value of:
a. 100 V b. 170 V c. 240 V d. 338 V
92. If two similar wire conductors are connected in parallel, their total resistance is: a. double the resistance of one wire b. one half the resistance of one wire c. the same as the resistance of one wire d. two-thirds the resistance of one wire 93. Which colour is not used in 1st band of a colour coded resistor:
a. brown b. white c. red d. black
94. Silver band represent the tolerance of:
95. Phase angle : Esmin, P-88 a. it is an angular distance between current and voltage in an a.c. circuit
b. it is always measured between the horizontal line and the resultant vector c. none of the above d. both (a) & (b)
96. Unit of inductance: Esmin, P-107
a. henry b. ohm c. mho d. none of the above
97. Diamagnetic materials have permeability: Grob, P-390
a. more than 1 b. from 50 to 500 c. less than 1 d. exactly 50
98. Vacuum has: Grob, P-408
a. high permeability b. high reluctance
c. low permeability and high reluctance d. high permeability and low reluctance
99. The resistance of a short circuit is: Grob, P-37
a. infinity b. zero c. always 100 d. more
100. What is characteristics of parallel circuit:
a. branch current are additive b. voltage are additive c. powers are additive d. (a) & (c) are correct 101. Magnetic field lines are considered to be:
a. coming out of north pole and enter south pole b. coming out of south pole and enter north pole
c. coming out of north pole but doesn‟t enter south pole d. depends on shape of magnet
102. The ability of magnet to hold its magnetism varies greatly with the type of metal and is known as: FAA-9A, P-302 a. reluctance b. retentivity c. permeability d. diamagnetic
103. The polarity of the statically induced voltage is determined by: Grob, P-431 a. Fleming‟s right hand rule for conventional current
b. Fleming‟s left hand rule for electronic current c. Thumb rule
d. Lenz law
104. Unit of mmf is: Grob, P-401
a. oersted in cgs b. gauss c. gilbert d. tesla
105. The direction of field around a positive charge is: FAA-9A, P-270 a. toward the charge b. away from the charge c. either (a) or (b) d. none of the above
106. If the third band is silver in color, the ___ digit must be multiplied by ___%: FAA-9A, P-280 a. third digit, 10% b. first two digit, 10%
c. third digit, 1% d. first two digit, 1%
107. If third band is gold in colour the first two digits must be multiplied by: B. L. Thareja, P-280
108. Tolerance is: FAA-9A, P-279, 280 a. The percentage variation between the marked value and the actual value of a resistor
b. fourth color band on the resistor c. both (a) & (b)
d. none
109. The example of intermittent duty relay switch is FAA-9A, P-320
a. battery relay switch b. starter relay switch c. both (a) & (b) d. neither (a) nor (b)
110. In a circuit with three parallel branches, if one branch opens, the main line current will be:
a. more b. less c. the same d. infinite
111. A 1- R1 and a 20 R2 are in series with a 30-V source, if R1 opens, the voltage drop across R2 will be:
a. zero b. 20 V c. 30 V d. infinite
112. If a fixed value of voltage is connected across a variable resistance: Grob, P-194 a. I will vary in direct proportion to R b. I will be inversely proportional to R
c. I will remain constant as R is varied d. none of the above
113. Number of coulombs passing through any given point in a conductor per second is: a. charge b. potential c. current(Ampere) d. both (a) & (c)
114. Unit of magnetic flux is: Grob, P-382
a. tesla b. Weber c. Gilbert d. none of the above
115. Unit of flux density is: Grob, P-383
a. tesla b. Weber c. Gilbert d. none of the above
116. The reasons of using horse shoe magnet instead of bar magnet in instruments is/are: Grob, P-387 a. it occupies less space b. has less air gap
c. it increases the flux density in the air gap d. all of the above
117. The ability of magnetic materials to concentrate magnetic flux is known as: Grob, P-386 a. permittivity b. permeability c. flux density d. field intensity
118. A resistor with a power rating of 25w is most likely a: Grob, P-51 a. carbon composition resistor b. metal film resistor
c. surface mount resistor d. wire wound resistor
119. A potentiometer is a: Esmin, P-101
a. three terminal device used to vary the voltage in a circuit; b. two-terminal device used to vary the current in a circuit c. fixed resistor
d. two-terminal device used to vary the voltage in a circuit
120. Mark the correct statement about electricity and magnetism: Grob, P-409 a. current is analogous to flux and potential is analogous to flux density
b. current is analogous to magneto motive force and reluctance is analogous to resistance c. current is analogous to flux and resistance is analogous to magneto motive force d. current is analogous to flux and potential is analogous to magneto motive force
121. Mark the correct statement: FAA-9A, P-302
a. ferromagnetic materials have high permeability whereas diamagnetic materials have permeabilities slightly less than one
b. a. ferromagnetic materials have high permeability whereas diamagnetic materials have permeability slightly more than one
c. paramagnetic materials have permeabilities slightly less than one and diamagnetic materials have permeabilities slightly more than one
d. paramagnetic materials have permeabilities slightly more than one and diamagnetic materials have very high permeabilitities
122. The d.c. series motor should never be switched on at no load because: B. L. Thareja, P-1030 a. the field current is zero b. the machine does not pick up
c. the speed becomes dangerously high d. it will take too long to accelerate 123. The most efficient form of damping employed in electrical instrument is:
a. air friction b. fluid friction c. eddy currents d. none of the above
124. A simple potentiometer is correctly called a :- B.L. Thareja, . Page – 55 a. current devider b. voltage stabilizer
c. variable resistor d. voltage divider
125. The unit of capacitance is :- B.L. Thareja, . Page – 55
a. farad b. coulomb c. volt d. metre
126. The time constant of an R-C circuit is defined as the time during which capacitor charging current becomes
………… percent of its……… value:- B.L. Thareja, Page-157
a. 37, final b. 63, final c. 63, initial d. 37, initial
127. The magnetizing force produced by a solenoid depends on :-
a. the number of its turns b. the current carried by it c. its length d. all the above
B.L. Thareja, Page-193 128. Aluminium can be classified as a ……….. material :-
a. Para magnetic b. Force magnetic c. Dia magnetic d. Soft magnetic
B.L. Thareja, Page-193 129. Whenever a magnet is quickly brought towards an open circuited stationary coil :-
a. A current is induced in it b. Work has to be done c. e.m.f. is induced it d. Power is spent
B.L. Thareja, Page -219 130. The direction of induced e.m.f. in a coil may be found with the help of :-
a. faraday‟s law b. Lenz‟s law
c. fleming‟s left hand rule d. steinamety law
B.L. Thareja, . Page – 219 131. An e.m.f. is induced in the coil whenever flux through it :- (B.L. Thareja, P -220) a. Is decreased b. Is increased c. Is abruptly reduced to zero d. All the above
132. Capacitance does NOT depend upon which factor :- ( T.K. Eismin,Page-103)
a. plate area b. plate thickness
133. Which of the following material has a negative temperature coefficient of resistance ?
(B.L Thareja, Page – 8)
a. Brass b. Copper c. Aluminium d. Carbon
134. Carbon composition resistors are most popular because they :- (AC 65-9A, Page-278) a. cost the least b. are smaller in size
c. can withstand over loads d. do not produce electric noise
135. Which of the following statement is true both for a series and a parallel dc circuit ?
( T.K. Eismin, Page – 107) a. powers are additive b. voltages are additive
c. currents are additive d. elements have individual currents
136. For a given voltage, four heating coils will produce maximum heat when connected :-
a. All in parallel b. All in series
c. With two parallel point in series d. One pair in parallel with the other two in series
T.K. Eismin, Page – 8
137. A cylindrical wire, 1 m in length, has a resistance of 100 ohm. What would be the resistance of a wire made from the same material if both the length and cross sectional area are doubled ? B.L Thareja, Page-7 a. 200 ohms b. 400 ohms c. 100 ohms d. 50 ohms
138. The working voltage of a capacitor in an A.C circuit should be :- AC 65-9A, Page-351 a. equal to the highest applied voltage
b. at least 20% greater than the highest applied voltage c. at least 50% greater than the highest applied voltage d. none of these
139. Higher the self-inductance of a coil :- (T.K. Eismin, Page – 107)
a. lower the e.m.f. induced in it
b. longer the delay in establishing steady current through it c. greater the flux produced by it
d. lesser its flux linkage
140. Mutual inductance between two magnetically coupled coil depends on :- (B.L Thareja, Page-176) a. The number of their turns b. Permeability of the core
c. Cross sectional area of their common core d. All the above
141. Permanent magnets are normally made of :- (T.K. Eismin, Page-8)
a. Aluminium b. Wrought iron
c. Cast iron d. Alnico alloys
142.those magnetic materials are best suited for making armature and transformer cores which have :- a. low permeability and high hysterisis loss
b. high permeability and low hysteresis loss c. low permeability and low hysteresis loss d. high permeability and high hysteresis loss
143. Those materials are well suited for making permanent magnets while have :- (9A/303) a. high retentivity and high coercivity
b. high retentivity and low coercivity c. low retentivity and low coercivity d. low retentivity and high coercivity
144. In a magnetic material, hysteresis loss takes place primarily due to :- (AC 65-9A, Page-450) a. flux – density lagging behind magnetizing force b. molecular friction
c. its high retentivity d. rapid reversals of its magnetization
145. Circuit breakers are located :- ( E.H.J. Pallet, Page-115)
a. generally far from the power source b. close to the power source
c. at any location compatible to the particular unit d. so as not to be exposed to heat of any kind
146. All resetable circuit breakers :- ( E.H.J. Pallet, Page-113)
a. Should open the circuit irrespective of the position of operation control when overload exits b. Should open the circuit irrespective of the position of operating control when a circuit fault exists c. Are referred to as trip free circuit
d. All of the above
147. Which particle of an atom actually moves in the production of an electric current : (BL Thereja-Pg 1)
a. the proton b. the electron
c. the neutron d. all three
148. The term that describes the combined resistive force in an AC circuit is : (Thomas K Eismin- Pg-87)
a. resistance b. capacitance
c. total resistance d. impedance
149. If a series R-L-C circuit contains 10 ohm of resistance, 20 ohm of inductive reactance, and 30 ohm of
capacitive reactance it is said to be (Numerical)
a. inductive b. in resonance
c. resistive d. capacitive
150. The opposition offered by a coil to the flow of ac is called: (Thomas K Eismin- Pg-87)
a. conductivity b. impedance
c. reluctance d. inductive reactance
151. An increase in which of the following factors will cause an increase in the inductive reactance of a circuit (Thomas K Eismin- Pg-87) a. capacitance & voltage b. inductance & frequency
c. voltage and resistance d. resistance & capacitive reactance
152. Which statement is correct in reference to electrical resistance (Numerical)
a. two electrical devices will have the same combined resistance if they are connected in series as they will have if connected in parallel
b. if one of 3 bulbs in a parallel lighting circuit is removed, the total resistance of the circuit will become greater
c. an electrical device that has a high resistance will use more power than one with a low resistance with the same applied voltage
153. Through which material will magnetic lines of force pass most readily (BL Thereja Pg-245)
a. copper b. iron c. aluminium d. titanium
154. Unit of capacitive and inductive reactance is (BL Thereja Pg-201)
a. farad & henry b.ohm & henry
c. farad & ohm d. ohm & ohm
155. The maximum value of charge in a capacitor reached at: Thomas K Eismin Pg-105
a. 2 Time constant b. 3 Time constant
c. 4 Time constant d. 6 Time constant
156. Dielectric strength is maximum in: FAA-9A Pg-351
a. Paper b. Glass c. Mica d. Air
157. In one time constant, capacitor takes the charge upto ___ % of its full charge
Thomas K Eismin Pg-105
a. 63.2 b. 36.7 c. 20.6 d. 80.2
158. What is the power factor of a parallel resonance circuit? BL Thereja Pg-555
a. Unity b. Zero c. 0.5 d. 0.866
159. A circuit breaker that can not be reset when the circuit fault exist is called: EHJ Pallett Pg-113 a. Electric CB b. Non-resettable CB c. Trip free CB d. Polarized CB
160. For sensing angular position the ________ switch is used
a. Proximity b. Thermal switch EHJ Pallett Pg-104
c. Micro switch d. Mercury switch
161. Thermal switch in the fire warning system is operated above:
a. 300 C b. 400 C c. 500 C d. 500 C EHJ Pallett Pg-106 162. Closing of freight door is normally indicated with the help of:
a. Relays b. Proximity switch EHJ Pallett Pg-106
c. Mercury switch d. None
163. “HRC” terms used with : EHJ Pallett Pg-112
a. CB‟s b. Switches c. Relays d. Fuses
164. The unit of resistivity is: BL Thereja Pg-4
a. Ohm-meter b. Ohm/Meter c. Ohm-centimeter d. Ohm/Sq cm.
165. A three phase synchronous motor is well suited for driving :- B.L Thareja, Page – 651
a. fluctuating loads b. printing presses
c. motor generator set d. vacuum cleaners
166. Current changing at the rate of 0.5 Amp. / Sec. induces on e.m.f. of 2V in a coil. The self inductance of the
coil in Henry is :- B.L Thareja, Page – 219
a. 4 Henry b. 2 Henry c. 1 Henry d. 3 Henry
167. The starting winding of a single phase motor is placed in the :- E.H.J. Pallet, Page-143 a. Rotor b. Stator c. Armature d. Field
168. In synchronous motor, damper winding is provided in order to :- (T.K. Eismin, page-186) a. stabilize rotor motion
b. suppress rotor oscillations c. develop necessary starting torque d. both (2) & (3)
169. While running , a synchronous motor is compelled to run at synchronous speed because of :-
(AC 65-9A, Page-457) a. damper winding in its pole faces
b. magnetic locking between stator and rotor poles c. induced e.m.f. in rotor field winding by stator flux d. compulsion due to Lenz‟s law
170. The Hysterisis motor works on the principle of : (EHJ Pallette , P-144) a. Flemings right hand rule
b. Hysteresis principle
c. As in „2‟ and the rotor rotates at Synchronous speed
171. Synchronous motor runs at :- AC 65-9A, Page-457
a. Synchronous speed at no load
b. Less than synchronous speed at all loads
c. It runs at synchronous speed from no load to full load d. Both (1) & (3) are correct
172. In 3 Phase induction motor :- AC 65-9A, Page-453
a. at no load, rotor speed is slightly less than synchronous speed b. with increase of load, rotor speed decreases
c. with decrease of load rotor speed increases d. all are correct
173. In 3 Phase inductions motor % slip depends upon :- (AC 65-9A, Page-453)
a. load b. line voltage of three phase A3. Supply
c. number of conductors on rotor d. all are correct
174. If a single phase induction motor runs with noise, the more likely defect is :- ( B.L Thareja, Page-62 )
a. Improper fuses b. Shorted running winding
c. Open starting winding d. Worn bearing
175. The principle of statically inducted e.m.f. is utilized in :- ( B.L Thareja, Page-553)
a. Transformer b. Motor
c. Generator d. Battery
176. . In End to Center band system, if the tolerance band shows blue color, the tolerance value will be:
a. 6% b. 2% BL Thereja Pg-280
d. 4% d. None of the above
177. . Carbon composition resistors have the demerits of: a. More cost b. Larger in size
c. Produce electric noise d. None of the above BL Thereja Pg-25 178. The speed of a D.C. motor can be controlled by varying :- B.L Thareja, Page – 321
a. Its flux
b. Armature circuit resistance c. Applied voltage
d. All the above
179. When load is removed, which motor will run at the highest speed :- B.L Thareja, Page – 311
a. Shunt b. Series
c. Cumulative d. Differential compound 180. The armature torque of a D.C motor is a function of its
a. Pole flux b. Armature current
c. Speed d. Both (a) & (b)
181. A universal motor has variable speed characteristics because it is :- B.L Thareja, Page – 627
a. series wound b. compound would
c. operated on both D.C and A.C supplied d. wholly laminated
182. Polarized relay is normally used in: FAA-9A Pg-401
a. Generator-Battery circuit b. Generator-Load circuit c. Generator-Lighting circuit d. None
SERVOMECHANISMS & AMPLIFIERS
183. All the synchros are working on: (Ref. A/c Inst. Pallet, 23)
a. transformer principle b. resistance principle c. inductor principle d. capacitance principle
184. Which component is not used in torque synchro: (Ref. A/c Inst. Pallet, 232)
a. motor b. amplifier
c. motor and amplifier d. none of the above
185. Generally torque synchro are used for transmitting: (Ref. Pallet Integrated, 135) a. power plant datas and position indication b. navigational datas
c. manometric datas d. inertial datas
186. Control synchro is used for: (Ref. Pallet Integrated, 136)
a. power plant data transmission b. close loop servo system c. position indication flap position indication
187. Differential synchro is used for: (Ref. Pallet Integrated, 136)
a. power plant data. manometric data c. position indication
d. output depends upon two input data
188. Resolver synchro is used where we require Cartesian coordinate of a point to:
(Ref. Pallet Integrated, 143)
a. R Cos b. R Sin
189. Polar coordinate is used to find out resultant of: (Ref. Pallet Integrated, 149)
a. R Cos b. R Sin
c. R Cos and R Sin d. R Tan
190.In torque synchro if the rotor connection is reversed then: (Ref. Pallet Integrated, 139) a. no effect on output b. output is advanced by 900
c. output is advanced by 2700 d. output is advanced by 1800
191. If there is cycle shift of stator connection torque synchro then output datum is advanced by:
a. 2400 b. 2700 c. 1800 d. 900 (Ref. Pallet Integrated, 139)
192. In torque synchro if stator coil connection of two lead are interchanged then:
(Ref. Pallet Integrated, 139) a. output is advanced by 900 b. output is advanced by 1800
c. output is advanced by 2700 d. reverse rotation of output rotor
193. In resolver synchro where polar is connected to Cartesian R3 & R4 rotor coils are shorted to:
(Ref. Pallet Integrated, 147) a. prevent burning b. prevent hunting
c. improve accuracy d. as in c & limit spurious response
194.In control synchro supply is given to: (Ref. Pallet Integrated, 14)
a. transmitter stator b. transmitter rotor
c. receiver stator d. receiver rotor
195.Resolver syschro consists of:
a. four rotor coil b. four stator coil (Ref. Pallet Integrated, 146)
c. two rotor and stator coil d. four rotor and stator coil
196. When pilot is flying the a/c manually the pilot and his control surface together may be termed as: (Ref. AFC Pallet, 72)
a. auto flight b. manual flight
c. man / machine close loop servo system d. all are correct
197. The role of AFCS is to: (Ref. AFC Pallet, 73)
a. over come a stability and control deficiency b. improve handling and ride quality
c. carry out series of maneuver which pilot is unable to perform d. all are correct
198. Servo system must be able to perform: (Ref. AFC Pallet, 83)
a. detect difference between input and output b. amply the error signal
c. control the closing of servo loop by providing feedback d. all are correct
199. Servo mechanism are coming under two classes may function as: (Ref. AFC Pallet, 83) a. position control b. speed control
c. position and speed control d. differentiator and integrator
200. In position control servo system the amplifier output is equivalent to: (Ref. AFC Pallet, 84) a. 1 b. 0 c. K (1 - 0) d. K (0 - A)
201. In speed control servo system output from the amplifier is:
a. K (V1-V0) b. K (V0-Va)
c. V1 d. Vo (Ref. AFC Pallet, 84)
202. What are the type of input in servo system: (Ref. AFC Pallet, 84)
a. step input b. ramp input
c. step and ramp input d. step and ramp output
203.Impositon feed back system if there is step input: (Ref. AFC Pallet, 85) a. continuous oscillation b. load comes to rest at null point
c. load lags behind d. all are correct
204. Inherent friction cause: (Ref. AFC Pallet, 86)
a. light damping b. heavy damping
c. critical damping d. all are correct
205. The degree of damping which prevent any over shoot is known as: (Ref. AFC Pallet, 86)
a. light damping b. critical damping
c. optimum damping d. heavy damping
206. Damping which allows small over shoot and smallest settling time is known as: (Ref. AFC Pallet, 86) a. optimum damping b. critical damping
c. light damping d. heavy damping
207. Small force of constant magnitude opposing servo motor is known as: (Ref. AFC Pallet, 86) a. coulomb friction b. viscous friction
c. eddy current d. lubricant
208. In velocity feed back damping if there is ramp input: (Ref. AFC Pallet, 88)
a. no velocity lag b. over shoot
c. velocity lag increase d. none of the above
209. In error rate damping when input and output shafts are at equal velocity then: Ref. AFC Pallet, 88 a. no error signal b. there is an error signal
c. error signal is more d. all are correct
210. In ECAM system which mode is the automatic mode? EHJ Pallette, P-133
a. Flight Phase b. Cautionary
c. Advisory d. Both (a) and (c)
211. In EICAS system, which is a “level A warning”? TK Eismin, P-359 a. Cabin Depressurization b. Engine Fire
c. Both (a) and (b) in display form d. Both (a) and (b) in display as well as in aural form
212. In ECAM system: EHJ Pallette, P-134
a. The graphical display is given by the R.H unit b. The graphical display is given by the L.H unit
c. As in a. and advisory message color change to white after corrective action taken d. As in b. and advisory message color change to white after corrective action taken
213. CRT used in A/C instrument displays are: TK Eismin, P-123 a. Electromagnetic deflection type b. Electrostatic deflection type
c. Both „1‟ & „2‟
BONDING & SCREENING
214. In aircraft having non metallic structure: (Ref. EHJ Pallet, 88)
a. four or more copper strip type conductors are used extending whole length of fuselage b. they are not more than six feet apart as measured around the periphery of fuselage
c. the fuselage earthing strips are connected to further strips which follow the leading and trailing edges from root to tip of each wing and horizontal stabilizer
d. all the above
215. Corona discharge in a/c is prevented by: (Ref. EHJ Pallet, 74)
a. static discharger b. screening
c. potting d. none of the above
216. What is true about bonding tester: (Ref. CAP-II, Ch-EEL/06)
a. 60 lead is connected to a/c main earth point
b. 6 lead two prongs are connected where there is joint
c. it has got one 1.2v cell and calibration is done by standard resistances provided d. all the above
217. Bonding and grounding are made to provide: (Ref. EHJ Pallet, 92)
a. current return path
b. protection of person from shock hazard c. stability of radio reception and transmission d. all the above
218. The tags or lugs on bonding jumpers are generally fitted by: CAIP-II/943 a. soldering method b. crimping method
c. sintering method d. nuts & bolts
219. The maximum primary bonding resistance between the extremities of the fixed portion of all metallic aircraft
is: CAIP-II/496
a. 0.1 ohm b. 0.01 ohm c. 0.05 ohm d. 0.001 ohm
220. Mark the correct statement: E.H.J. Pallet, P-92
a. precipitation charges are those which are induced into an aircraft when flying into electric fields created by certain types of cloud formation
b. electrostatic charges are built up on the outer surface of an aircraft due to friction contact with rain particles, snow and ice crystals, dust, smoke and other air contamination
c. precipitation static charges are built up on the outer surfaces of an aircraft due to frictional contact with rain particles, snow and ice crystals, dust, smoke and other air contamination whereas charges of electrostatic are those induced into an aircraft when flying into electric fields created by certain types of cloud formation.
d. none of the above
221. Mark the correct statement: E.H.J. Pallet, P-94
static charges
b. classification of secondary bonding is determined by the magnitude of current to the expected from electro statically induced charges
c. bonding is classified as primary and secondary, such classification being determined by the magnitude of current to be expected from electro statically induced charges and precipitation static charges respectively.
d. bonding is classified as primary and secondary, such classification being determined by the magnitude of current to be expected from precipitation static charges and electro statically induced charges respectively.
ELECTRONICS
222. The doping materials are called impurities because they: (Ref. BL Theraja) a. decrease the number of charge carriers
b. change the chemical properties of semi conductors c. make semi conductors less than 100 percent pure d. alter the crystal structure of pure semi conductors
223. Feedback in an amplifier always helps to: (Ref. BL Theraja)
a. control its output b. increases its gain
c. decreases its input impendence d. stabilize its gain
224.In normal operation of p-n-p transistor, its junctions are biased: (Ref. BL Theraja) a. both forward
b. both reverse
c. emitter base – reverse, collector base – forward d. emitter base – forward, collector base – reverse
225. An SCR can be turned off by: (Ref. BL Theraja-1991, 817)
a. anode current interruption
b. reversing polarity of anode – cathode voltage c. reducing current through SCR below the holding
d. any of above method can be used independently
226. The logic symbol represents: Pallet-225
a. an AND gate b. a NOR gate c. an OR gate d. an XOR gate
227. In order to energize the relay in the circuit shown below here the logic state at the inputs must be
a. log 0 at points A & B b. 0 at point A and 1 at point B c. 1 at both points d. 0 at both points
A B C
1 1 1 1 0 1 0 1 1 0 0 0
228. The truth table shown here corresponds to: Pallet-226 a. an OR gate
b. an AND gate c. a NOR gate d. an XOR gate
229. The circuit shown here performs a logic: Pallet-226
a. AND function b. OR function c. NAND function
230. DTL family Logic employs: (BL Thereja, P-2376)
a. Diode, Resistor, Transistor b. Diode and resistor
c. Resistor & Transistor
231. In a normally working PNP transistor, both base and collector are at _____potential w.r.t the emitter
(BL Thereja Pg-1975)
a. +ve b. –ve c. either (1) or (2) d. neither (1) or (2)
232. A transistor does not conduct unless its __________ base junction is forward biased (BL Thereja Pg-1975)
a. emitter b.collector
c. both (1) and (2) d. either (1) or (2)
233. FETs have similar properties to (VK Mehta Pg-488)
a. PNP transistors b. NPN transistors
c. Thermionic valve d. UJT
234. The smallest negative grid voltage, for a given plate voltage, at which plate current becomes zero is known as (VK Mehta Pg-44) a. grid cutoff bias b. grid cut in bias
c. break over voltage d. break down voltage
235. The band width of the band pass filter depends upon (Thomas K Eismin Pg-289) a. resistance of inductor b. No. of elements used
c. both (1) and (2) d. either (1) or (2)
236. Which transistor has the highest voltage and power gain ? (BL Thereja Pg-2059)
a. CB b. CE c. CC d. Both (1) and (2)
237. The --- configuration on of transistor is suitable for high input to Low output impedance matching (BL Thereja Pg.- 2032) a. CB b. CE c. CC d. All of the above
238. The common base configuration of transistor is used for: (VK Mehta Pg-227) a. Impedance matching (high frequency signal)
b. audio frequency signal
c. impedance matching (Low frequency signal) d. none of the above
239. Germanium has how many electrons in the outermost orbit- (VK Mehta Pg-119)
a. 1 b. 2
c. 3 d. 4
240. Silicon & Germanium are the examples of- (VK Mehta Pg-120)
a. conductor b. semiconductor
c. super conductor d. dielectric
241. A Zener diode has how many terminals? (BL Thereja Pg-1908)
a. 1 b. 2 c. 3 d. 4
242. A silicon controlled rectifier (SCR) has how many terminals? (BL Thereja Pg-2160)
a. 1 b. 2 c. 3 d. 4
243. Aquadag coating done in CRT is to- (BL Thereja Pg-2394)
a. avoid dust formation on the screen b. avoid mixing of colours
c. capture secondary electrons d. accelerate thermions
244. Sweep generator generates : (BL Thereja Pg-2392)
a. Triangular wave form b. Sawtooth waveform c. Sinusoidal Waveform d. all of these
245. A Bipolar transistor has how many terminals? (BL Thereja Pg-1974)
a. 1 b. 2
c. 3 d. 4
246. In semiconductor diodes, the current is made of- (BL Thereja Pg-1855)
a. electrons b. holes
POWER DISTRIBUTION
247. Merz-price protection system is also known as: (Ref. EHJ Pallet, 122) a. over current protection b. under voltage protection
c. differential protection d. over voltage protection
248. Differential fault means: (Ref. EHJ Pallet, 12)
a. difference between the current leaving the generator and the current arriving at the bus bar b. voltage difference between generator and bus bar
c. frequency difference between generator and bus bar d. none of the above
249. Essential loads are connected to: (Ref. EHJ Pallet, 77)
a. battery bus bar b. generator bus bar c. both a & b d. vital bus bar
250. When external AC power is connected to TRU, its output: (Ref. EHJ Pallet, 63) a. energies d.c. control relay circuits
b. is connected to d.c. bus bar to operate d.c. consumers c. both a & b are correct
d. is used sparingly on ground
251. If all the generators fail during flight, the essential services will be maintained by: (Ref. TK Eismin, 243)
a. A.C. bus b. hot bus
c. d.c. bus d. none of the above
252. In constant frequency load system which is correct statement: (Ref. EHJ Pallet, 49 & 50) a. reactive load sharing is done by field excitation
b. active load sharing is done by governor setting c. load sharing depends on the size of the generator d. both a & b are correct
253. In twin engine a/c in flight, power is normally supplied by: (Ref. EHJ Pallet, 77) a. two main generators b. one generator and APU generator
c. two main generators and batteries d. batteries and APU generator
254. Which is true about power distribution system: (Ref. EHJ Pallet, 76) a. power consuming equipment must not deprived of power in the event of power source failure unless the total power demand exceeds the available supply
b. fault on the distribution system, e.g. fault current, grounding or earthing at bus bar should have the minimum effect on system functioning and should constitute minimum fire risk
c. power consuming equipment faults must not endanger the supply of power to other equipment d. all are correct
255. A/c which operate only on a.c. generators as a primary source of electrical power normally provide current suitable for battery charging through the use of: (Ref. EHJ Pallet, 78) a. a step down transformer and rectifier unit
b. on invertors and voltage dropping resistor c. APU generator
d. all are correct
a. consumer equipment b. cockpit
c. tails d. junction boxes or distribution panels
257. Bus bars are made of: AES, P-76-77
a. silver b. aluminium
c. copper d. either (b) or (c)
258. When braided copper wire is used as bus bar then it will be a: AES, P-76-77
a. main bus bar b. subsidiary bus bar
c. essential bus bar d. none of the above
259. Vital services are connected: AES, P-76-77
a. directly to batteries b. directly to generators
c. either (a) or (b) d. none of the above
260. Non-essential services are connected to: AES, P-76-77
a. battery bus bar b. generator bus bar
c. both (a) & (b) d. none of the above
261. The main source of power supply is provided by: AES, P-76-77
a. generators b. batteries
c. invertors d. APU
262. The stand by source of power is provided by: AES, P-76-77
a. batteries b. generators
c. invertors d. APU
263. In all AC aircraft the DC supplies are provided from/by: AES, P-76-77
a. batteries b. transformer rectifier units (TRUs)
c. separate DC generator d. none of the above
264. The configuration of the transformers of the TRU are: AES, P-65
a. star delta star b. star delta delta
c. star star delta d. delta star delta
265. The millivolt drop of the shunt installed in the TRU is: AES, P-63
a. 100 mV at 100 A b. 100 mV at 50 A
c. 50 mV at 50A d. 50 mV at 100 A
266. TRUs are designed to operate at: AES, P-63
a. single phase input of 115 volts AC, 400 c/s b. three phase input of 200 volts at 400 c/s c. DC input of 26 volts
d. none of the above values are correct
267. TRUs are cooled by: AES, P-63
a. blast air b. ram air c. cooling fans d. natural convection
268. The number of terminals on the shunt of TRUs are: AES, P-65
a. two b. four c. six d. eight
269. The thermal switches inside the TRUs operate at: AES, P-63
c. 100 C and 150 C d. 50 C and 100 C
270. Mark the correct option about reverse current circuit breaker: AES, P-115 a. series coil assists the shunt coil when generator is charging the batteries
b. series coil opposes the shunt coil when generator is charging the batteries
c. series coil assists the shunt coil when reverse current flows from battery to the generator d. none of the above is correct
271. Mark the correct statement about reverse current circuit breaker: AES, P-115 a. series coil assist the shunt coil when reverse current flows from battery to generator
b. series coil opposes the shunt coil when reverse current flows battery to generator c. series coil assists the shunt coil when generator is charging the battery
d. both (b) & (c) are correct
272. In the parallel operation of generator in aircraft when any generator fails: AES, P-77 a. the loads of the failed generator are supplied by batteries
b. the loads of the failed generator are supplied by the available generator/generators c. only essential loads are supplied by the running generator/generators
d. none of the above is correct
273. In the A.C. split bus bar system of operation when any generator fails: AES, P-78 a. its loads are supplied by the other operating generator
b. only essential a.c. loads are supplied by the operating available generator c. TRUs become in operative
d. all the above are correct
274. In the 3-pin external power receptacle: AES, P-70
a. the smaller pin is positive b. the smaller pin is negative
c. as in (a) and it controls the supply to external power relay d. none of the above is correct
275. The purpose of the battery in the aircraft is: AES, P-69
a. to provide main source of electrical power
b. to provide emergency source of power when main generator/generators fail c. to provide internal start
d. none of the above is correct
276. Mark the correct answer about the external D.C. supply receptacle on the aircraft: AES, P-70 a. it has two mater pins and one bigger pin
b. it has two bigger pins and one smaller pin c. as in (a) and one of the smaller pin is negative d. as in (b) and one of the bigger pins is positive
277. Mark the correct answer: AES, P-70
a. external power relay is located inside the ground power unit (GPU)
b. external power relay is located inside the aircraft and is controlled by the smallest pin of the external supply receptacle
c. as in (a) and is controlled by one of the two bigger pins of external supply receptacle d. none of the above
278. The main contacts of the external supply contactor in the multiple d.c. bus bar system connect the external
a. no. 1 D.C. bus bar b. no. 2 D.C. bus bar
c. no. 3 D.C. bus bar d. as in (b) and vital bus bar
279. Magnetic indicators of in the multiple D.C. bus bar system indicate: AES, P-71 a. satisfactory connection of generators to the bus bar
b. satisfactory connection of batteries to the bus bar
c. satisfactory connection of external power to the bus bars d. none of the above is correct
280. Mark the correct statement about the multiple d.c. bus bars system being energized by the external power: AES, P-71 a. the main contacts of the external supply contactor provide the supply to the coils of No. 1 & No. 3 bus-tie connectors
b. the auxiliary contacts of the external supply contactor connect the external supply to the bus bar
c. the main contacts of the external supply contactor connect the external supply to the bus bars while the auxiliary contacts provide the supply to the coils of No. 1 and No. 3 bus the contactors.
d. none of the above
281. Mark the correct answer about the magnetic indicators of the multiple d.c. bus bar system being energized by
external power: AES, P-71
a. supply to the magnetic indicators are provided through the main contracts of the external supply contactor and bus tie contactors
b. supply to the magnetic indicators are provided through the auxiliary contacts of the external supply contactor and the bus-tie contactors
c. supply to the magnetic indicators are provided by the bus bars directly d. none of the above is correct
282. External supply receptacle is generally located at: AES, P-69 a. wings bottom side b. wheel bays
c. tail plane d. the sides of the fuselage
283. When external A.C. supply is connected to the aircraft it is indicated by: AES, P-72 a. amber light b. red bight c. green bight d. none of the above
284. The external a.c. power receptacle has: AES, P-73
a. at least 2 bigger pins b. at least 3 bigger pins c. at least 4 bigger pins d. at least 5 bigger pins
285. The external power receptacle for APU starting has: AES, P-72
a. two bigger +ve pins and one smaller –ve pin b. two bigger –ve pins and one smaller +ve pin
c. one +ve & one –ve bigger pin and one smaller +ve pin d. one +ve & one –ve bigger pin and one smaller –ve pin
286. One of the function of auxiliary power unit is: AES, P-73
a. to supplement the delivery of air to the cabin during landing
b. to supplement the delivery of air to the cabin during low altitude flying c. to supplement the delivery of air to the cabin during takeoff and climb d. none of the above
287. APU is normally started by: AES, P-73
a. batteries b. generators
b. invertors
d. APUs are started by separate generators provided at the tail section of aircraft
288. Silver-coated copper wire is used for temperatures upto: Eismin, P-56 a. 221 F (105 C) b. 392 F (220 C)
c. 500 F (260 C) d. none of the above
289. The capacity of a battery is measured in: Pallet-220
a. volts b. cubic centimeters c. ampere-hours d. by the number of plates 290. The phase voltage of a three-phase star-connected a.c. generator is: Pallet-221 a. equal to line voltage b. greater than line voltage
c. less than line voltage d. equal to2 times max voltage
291. The ratio of true power to apparent power of an AC circuit is known as: Pallet-221 a. reactive power b. power factor
c. real power d. total power
292. Power factor is the ratio of: Pallet-221
a. true power to apparent power b. apparent power to true power c. apparent power to real power d. apparent power to impedance
293. If a source maintains a constant voltage at the input to the line then any variation in the load on line will cause: FAA-15A, P-435 a. variation in line current
b. as in (a) and also variation in IR drop in line c. no effect on line current and IR drop
d. variation in line current but no variation in IR drop
294. In a CSD unit, the control cylinder is mechanically coupled to the: Pallet-221 a. variable displacement unit b. fixed displacement unit
c. governor d. none of the above
295. The governor of a CSD unit is driven by the:
a. input gear b. input ring gear c. output gear shaft d. none of the above 296. A CSD unit which has been disconnected during flight:
a. may only be reconnected on the ground b. may be recommended in flight by re-set shutdown c. automatically resets of engine shutdown
d. none of the above
297. Rectification is the process of converting:
a. a high value of AC into a lower value b. AC into DC
c. AC into DC d. none of the above
298. An “N-type” semiconductor is one having: Pallet-222
a. an excess of “holes‟ b. a deficiency of holes c. an excess of electrons d. none of the above
a. battery, generator, alternator b. vital, essential, non-essential
c. TRU, engine, APU d. none of the above
300. The services which can be isolated in an in flight emergency for load shedding purposes, and are connected to DC and AC busbars, as appropriate and which are supplied from a generator are called: Pallet-77
a. vital services b. essential services
c. non essential services d. none of the above
301. The services which are required to ensure safe flight in an in-flight emergency situation and are connected to DC and AC busbars, as appropriate and in such a way that they can always be supplied from a generator or from
batteries are known as: Pallet-77
a. vital services b. essential services
c. non essential services d. none of the above
302. Those services which would be required after an emergency wheel up landing and are connected directly to
battery are known as Pallet-77
a. vital services b. essential services c. non essential services d. none of the above
303. The output from the aircraft generating sources is coupled to one or more low impedance conductors which
are known as: Pallet-77
a. jumpers b. boding wires c. bus bars d. shorting clips
a. parallel bus bar system b. split bus bar system c. split parallel bus bar system d. none of the above
305. Circuits in which currents and voltages are only a few milli amperes and milli volts and which are extremely
essential utilize: Pallet-108
a. slugged relays b. polarized relays
c. heavy duty relays d. light duly relay
306. Current transformer are: Pallet-175
a. step-up transformers b. step-down transformers
c. have unity power factor d. as in (b) and are known as instrument transformers
307. “Thermal Runaway” is associated with: Pallet-23
a. lead acid battery b. nickel cadmium battery
c. primary battery d. generator
308. When an area is contaminated with alkali electrolyte the most suitable neutralizing agents used are/is:
CAIP/II/1000 a. saturated solution of bicarbonate of soda b. ammonic powder
c. borax powder d. boric acid solution
309. When an area is contaminated with sulphuric acid electrolyte, the most neutralizing agent used in:
CAIP/II/1000 a. boric acid solution b. boric acid crystals or powder
c. saturated solution of bicarbonate of soda d. saw dust
310. Acid has spilled on the floor. The correct action taken in sequence should be: CAIP/II/1000 a. wash the area with copious amounts of water, treat the affected area with borax powder and the whole area should be sealed with saw dust which should then be removed & buried
b. the affected area should be treated with ammonia powder, followed by washing down with copious amounts be soaked up with saw dust which should then be removed and buried
c. the acid should be socked up with saw dust which should then be removed and buried. The affected area should be treated with saturated solution of bicarbonate of soda, followed by washing down with copious amount of fresh water
d. the acid should be soaked up with saw dust which should then be removed and buried. The area should then be washed down with copious amounts of fresh water followed by treating the affected area with ammonia powder. 311. The method/methods of securing a generator to an accessories gear box are: Pallet-9 a. pulleys & belts method b. quill shaft method
c. flange or manacle ring method d. either (a) or (b)
312. Integrated drive generators means: Pallet-43
a. generator and starter in the same unit & side by side b. starter and CSD in the same unit & side by side
c. CSD and generator are mounted side by side to form a single compact unit d. generator and voltage regulator are mounted side by side to form a single compact unit
