‘X’ ELECTRICS PAR 9.

1. If a d.c generator produces voltage but the ammeter reads zero when load is turned
on, the probable cause is;
a. Burned out current limiter or fuse in the generator power lead
b. Reversed polarity of generator field
c. Open field circuit
2. The Interpole and compensating winding are connected in series with the brushes
of dc generators. The purpose is to:
a. Assist the shunt field winding
b. Regulate the output voltage
c. Control the effect of armature reaction
3. In large aircraft, the source of electrical power is normally:
a. A.C generator with constant speed
b. D.C generator of large capacity
c. A.C generator with variable speed
4. The operation of the carbon-pile type of voltage regulator is based on the fact that
the contact electrical resistance between the faces of carbon discs varies with the;
a. Actual area of discs
b. Speed of the generator
c. Pressure which hold the faces together
5. When RPM of a shunt-wound motor increase, the current drawn by it;
a. Decreases
b. Increases
c. Will remain the same
6. The principal advantage of the series-wound d.c motor is its;
a. Suitability for constant speed use.
b. High starting torque
c. Low starting torque
7. In shunt-wound motors the torque characteristics is such that they(motors) must be
started on;
a. Full load
b. Light or no load
c. Light, full or no load
8. To give warning of whether or not passenger entrance doors are fully closed and
locked it is more advantage to use;
a. Microswitch
b. Push switch
c. Proximity switch
9. The function of limiting resistors as protection device is to;
 a. Cut the current in case of high current flow
b. Reduce the resistance of the current
c. Reduce the peak current during starting
10. Function of ‘economy resistor’ of continuous rated circuit breaker is to;
a. Reduce coil current and prevent temperature rise
b. Re-trip the circuit breaker
c. Adjust the value of tripping current
11. The chemical principle during charging on Ni-Cad battery is;
a. Oxygen is removed from the negative plate and added to the positive
plate
b. Oxygen is removed from the positive plate and added to negative plates
c. Hydroxide group is removed from the negative plates and added to the
positive plates
12. A certain battery is rated 30 ampere-hours based on the five hour discharge rate, it
will
a. Deliver 30 amperes for 5 hours
b. Deliver 150 amperes for 5 hours
c. Deliver 6 amperes for 5 hours
13. To prevent reverse charging;
a. The polarity of the supply leads should be checked with the aid of a
centre zero type voltmeter
b. The polarity of each group of batteries should be checked with centre zero
type voltmeter
c. The polarity of supply leads should be checked with the aid of centre zero
type wattmeter
14. The minimum acceptable capacity of any battery for use on aircraft is
a. 100%
b. 50%
c. 80%
15. Which is the truest statement about charging Ni-Cad battery
a. Two or more batteries can be charged in series by constant-current method
if they require same charge rate
b. Two or more batteries can be charged in parallel by using constant-voltage if
they require same charge voltage
c. Both A and B are true
16. The algebraic sum of the voltage rise (drop) encountered in tracing around any
closed-loop current is;
a. Zero
b. 24V
c. 12V
17. The probable cause of too low speed in a motor is
a. High voltage
b. Low voltage
c. Short-circuit in the field circuit
18. Rectification is the process of converting
a. High value A.C into a lower value
b. Direct current into alternating current
c. Alternating current into direct current
19. The voltage required of a generator in a 24-volt system is
a. 24V
b. 28V
c. 12V
20. In voltage regulators, the control of output voltage is achieved by controlling the
a. RPM
b. Field strength
c. Number of armature windings
21. The external characteristics of a d.c generator means;
a. Relation between terminal voltage and load current
b. Relation between the actual e.m.f generated in the armature winding and the
load current
c. Relation between the actual e.m.f generated in the field windings and the
load current
22. The field winding of aircraft d.c generator are;
a. Parallel connected
b. Series connected
c. Series-parallel connected
23. If the cable code is 3-R-123-S-20-C, the R represents
a. Cable size
b. Circuit function
c. Cable segment
24. In an ammeter circuit with a shunt resistor a current of 0.01 amp causes full-scale
deflection of the needle and the resistance of the movement is 5 ohms. To use the
ammeter where the range of current is from 0 to 30 amps, the value of the shunt
resistance must be;
a. 167 ohms
b. 0.167ohms
c. 0.00167
25. How should a voltmeter be connected
a. In parallel with load
b. In parallel with source and series with load
 c. In series with load
26. The most satisfactory movement for measuring high frequency a.c values is;
a. Iron-vane movement
b. Hot-wire meter
c. A simple galvanometer
27. The current in a purely capacitive circuit will;
a. Lag the applied voltage
b. Lead the applied voltage
c. Be in phase with the applied voltage
28. The magnetic permeability of iron and its alloy is;
a. High
b. Low
c. Equal to one
29. Electricity is produce in a generator by electromagnetic induction and the direction
of the electromagnetic field produced is determined by;
a. Ohms law
b. Right hand rule
c. Left hand rule
30. The sensitivity of electric measuring instrument is determined by the amount of
a. Power required to produce full scale deflection
b. Voltage required to produce full scale deflection
c. Current required to produce full scale deflection
31. Lead-Acid batteries vary by type principally in the
a. Thickness of their plates only
b. Type of seperators employed only
c. Thickness of their plates and type of seperator employed
32. What period of time has been established as the discharge time in rating aircraft
battery capacity
a. 5 hours
b. 1 hour
c. No established time
33. One of the information below is a means of telling of a lead acid battery used in the
aircraft;
a. Amperage of a cell with full load
b. Gassing rate while charging at a normal rate
c. Specific gravity of the electrolyte
34. If battery acid is spilled in the battery compartment, the correct procedure to follow
is
a. Apply sodium bicarbonate powder to the affected area and wiped with oil
0soaked cloth
 b. Apply sodium bicarbonate powder to the affected area followed by
water wash
c. Apply water to the affected area until the acid turns cloudy white
35. To measure the rate of charge for Ni-Cad battery;
a. Carry out a measured discharge test
b. Check electrolyte relative density
c. Check battery voltage
36. During electrical leak check on Ni-Cd battery, the value of leak current was found to
be 0.02 amps. Do you consider this value as
a. Unimportant, since voltage is measured during leak check
b. Permissible
c. Unpermissible
37. When performing capacity recycling, a cell voltage of 1 volt was measured after 10
min of charge
a. The cell in your opinion is acceptable
b. The cell could be recycle a second time to be acceptable
c. The cell should be rejected
38. If it is necessary to return a battery to the manufacturer or approved overhaul
organisation it should be sent
a. In a charged condition
b. In accordance with manufacturers transportation requirements
c. In a discharged condition
39. After changing a component
a. C of M must be signed
b. C of C must be signed
c. C of C and C of M must be signed
40. Duplicate inspection means that;
a. The same licenced engineer inspects work done on controls twice
b. Two licenced engineer inspects work done on controls one inspecting one
side of controls while the other inspects the other side
c. Two licenced engineer inspects work done on controls one at a time
41. An aircraft has four engines with variable pitch propellers, the number of log books
to be kept for that aircraft are;
a. 9
b. 6
c. 5
42. Certificates of maintenance are usually valid for
a. 50 flying hours
b. 12 calendar months
c. Specified calendar period or flying hours
43. Signing the C of M signifies that the aircraft, its engines, radio and equipment are;
a. Maintained to the best ability of the maintenance engineer
b. Maintained in accordance with the approved maintenance schedule
c. Maintained in accordance with civil aircraft inspection procedures
44. It is necessary to keep separate log books for engine and propeller of an aircraft
a. When the propeller is of variable pitch type
b. When the propeller is of fixed pitch type
c. In all cases
45. The validity period of C of M can be found
a. In aircraft log book
b. Maintenance schedule
c. Maintenance manual
46. Certificate of fitness for flight issued under “A” conditions may be signed by
a. Surveyor
b. Licenced aircraft engineer on the type
c. Chief pilot
47. Every C of A shall specify
a. The category appropriate to the aircraft
b. The maximum take-off weight of the aircraft
c. The service life of the aircraft
48. The total number of hours flown by an aircraft is obtained from
a. The aircraft log book
b. The technical log
c. The operational manual
49. A non-licenced engineer can sign C of C if
a. The work does not involve the use of test equipment
b. He has 5 years working experience
c. He has company approval
50. Certificate of compliance is issued
a. By an appropriately licenced aircraft enginner to signify that the aircraft is
maintained in compliance with approval schedules and regulations
b. By chief inspector to signify that the maintenance schedule has been
complied with
c. By an appropriately licenced aircraft engineer to signify that the
repairs, modifications, overhaul and inspections have been carried out
with approved materials using approved methods
51. After the operating life of the aircraft, the certificate of compliance
a. Should be preserved for 2 years
b. Should be preserved for 6 months
c. Should be discarded
52. Equipments which must be approved before being installed into the aircraft include:
a. Life jacket and radio equipment
b. Mooring, anchoring and on-water maneuvering equipment
c. Torelies, whistle and sea anchores
53. The amount of spare fuses for all electrical circuits, the fuses of which can be
replaced in flight shall be;
a. Ten of each rating
b. Three to five of each rating
c. Ten percent of the number of each rating or three of each rating
whichever is greater
54. MOR scheme stands for
a. Maintenance organisation requirement
b. Mandatory occurrence reporting
c. Management of regulations
55. The following documents must always be on board the aircraft for flight;
a. Engine logbook, C of M and Maintenance Schedule
b. Maintenance Manual, Maintenance Schedule and flight manual
c. C of R, C of A and approved flight manual
56. For a newly acquired aircraft, the maintenance schedule must be prepared by
a. The operator
b. The CAA surveyor
c. The manufacturer
57. It is required that the civil aviation authority approves
a. The maintenance manual
b. Catering service providers
c. The minimum equipment list
58. Airworthiness directives applicable to an aircraft are
a. Mandatory
b. Optional
c. Are for information only
59. Impulse couplings (starters) when used are fitted
a. Along the magneto shaft
b. Along the drive shaft
c. Between the magneto shaft and drive shaft
60. The power supply needed for smoke detection systems is normally
a. 14 volts d.c
b. 115 volts d.c
c. 28 volts d.c
61. The indication of fire detection system in the event of fire is
a. Illumination of warning light
 b. Audible warning
c. Illumination of warning light and audible warning
62. The operation of unit type fire detector is caused by
a. Differential expansion of dissimilar metals with changes In
temperature
b. Variation in resistance of the elements with changes in temperature
c. Variation in capacitance of the element with changes in temperature
63. During insulation resistance test for cartridge unit, the acceptable value is
a. Not less than 20Mohm
b. Not more than 20Mohm
c. Not more than 20Kohm
64. A circuit with a voltage of 10 volt and current of 5 amps has a resistance of
a. 2 ohms
b. 5 ohms
c. 10 ohms
65. Three resistors R1=3 ohms, R2=6 ohms and R3=2 ohms are connected in parallel
with a battery of 12 Volts. The respective currents through R1,R2 and R3 are
a. 6 amps, 2 amps, 4 amps
b. 4 amps, 2 amps, 6 amps
c. 2 amps, 6 amps, 4 amps
66. A rotating armature magneto to be fitted to a 6-cylinder engine must be driven at
a. Half the speed of the engine
b. One and half the speed of the engine
c. The same speed as the engine
67. Bonding is necessary for aircraft
a. Dissipating static charges from the airframe
b. Protecting the airframe from ice formation
c. Safe distribution of electrical charges and current on the airframe
68. Navigation lights requirement is that every aircraft in flight or moving during the
hours of darkness shall display;
a. A green light at starboard wing tip, a red light at port wing tip, white
light visible from the rear of the aircraft
b. A red light at starboard wing tip, a green light at port wing tip, white light
visible from the rear of the aircraft
c. A white light at starboard wing tip, a green light at port wing tip, a red light
visible from the the rear of the aircraft
69. The cable most suitable for use where severe flexing under low-temperature
conditions is encountered e.g landing gear shock strut switch circuit is
a. EFGLAS
b. NYVIN
 c. NYVINMETSHEATh
70. One of the installations where coaxial cables are commonly used is
a. Cylinder head thermocouple connection to indicator
b. Radio, for connection of antennae
c. Ignition system
71. The height of a lock nut is;
a. Half the width of a normal nut
b. Twice the width of a normal nut
c. The same that of a normal nut
72. When using a stiff nut, how much thread should project through the nut after
tightening
a. None
b. At least one and a half
c. At least 3 threads
73. Spring washer can be used
a. Once only
b. As many times as you like
c. As long as they retain their tension
74. When using spring washer
a. Fit double spring washer without the plain washers
b. Fit coil round springs
c. Fit a plain washer between the spring washer and the component and
tighten down the nut to the correct torque
75. BA threads are used
a. Under (one quarter inch) 6.25mm diameter screw
b. Over (one quarter inch) 6.25mm diameter
c. Not used
76. The lead of a metric micrometer is****
a. Two revolutions of the thimble
b. One revolution of the thimble
c. Two amvil revolution
77. The lead of an English micrometer is
a. 1/50 inch
b. 1/40 inch
c. 1/25 inch
78. The taper of the taper pin is
a. 1 in 49
b. 1 in 48
c. 1 in 29
79. In wire locking, the untwisted length should not be more than
 a. 3/8 inch
b. Half inch
c. 3 inch
80. Locking plates may be used repeatedly provided;
a. That the serration remain in a good fit around the hexagon on the on
the or bolt
b. It is springy
c. It is thick
81. In drawing, centre-lines are identified by;
a. Short dashes
b. Thin long chain
c. Dotted lines
82. Orthographic projection is a projection having
a. Full face and 45 degree to the horizontal
b. Full face and 30 degrees to the horizontal
c. Two or more views to highlight necessary details
83. Magnetic flop detection is a type of;
a. Non destructive testing
b. Destructive testing
c. Hardness testing
84. Which of the following is a non destructive testing
a. Izod-impact test
b. Proof-stress test
c. Dye-penetrant testing
85. Alloying chromium with steel improves
a. Brittleness of steel
b. Malleability of steel
c. Hardness of steel
86. An aircraft operating in a sea area can be corroded as a result of salt water. This
type of corrosion is known as:
a. Chemical corrosion
b. Electrochemical corrosion
c. Intergranular corrosion
87. In an aircraft industry, phosphor bronze is used for;
a. Valves
b. Bearings bushes
c. Motor shafts
88. When a metal has been work-hardened during cold working, if it is going to be cold
worked further, it should be;
a. Annealed
 b. Tempered
c. Normalized
89. Case hardening is heat treatment used on;
a. Low carbon steel
b. Non-ferrous materials
c. High carbon steel
90. Hardness of a metal is determined by its;
a. Ability to withstand indentation
b. The ease with which a metal can be broken without changing shape
c. Either of the above
91. A circuit with 250 Volts a.c supplying current at 50Hz through 4.9 henry inductor
has a reactance value of;
a. 1000 ohms
b. 245 ohms
c. 770 ohms
Ans: XL=2πfL (1539.38)
92. Fuses and circuit breakers are;
a. Devices used to produce electricity in aircraft
b. Devices used to protect circuits from excessive current
c. Devices to give a warning alarm in the event of power failure
93. The resistance value of a thermistor;
a. Increases with increase in temperature
b. Increases with decrease in temperature
c. Remains the same with increase or decrease in temperature
94. The materials commonly used in bi-metallic switches are;
a. Brass and invar
b. Chrome and nickel
c. Brass and steel
95. Shunts are normally used;
a. In radio circuits
b. As heating elements
c. In ammeter circuits
96. Relay contacts are classified as;
a. Normally open, normally closed and change over contacts
b. Normally open, current limited, and high voltage contacts
c. Normally closed, high voltage and normally open
97. The solution for L = M + (N/P)2 transposed for N is;
a. N =√ (L−MP )
b. N = P √ (L−M )
c. N = P (L2 – M2)
98. The material from which a permanent magnet is manufactured must have;
a. High coercivity and high remanence
b. High coercivity and low remenence
c. Low coercivity and low remanence
99. Apparent power is calculated using formular
a. VI
b. I2R
c. V2/R
100. During a millivolt drop test, the millivoltmeter reads 150mV at 300A. Contact
resistance is therefore;
a. 0.0005 ohms
b. 50 milli ohms
c. 50 ohms