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1. The arc voltage produced in a.c circuit breaker is
always
A. In phase with the arc current
B. Lagging the arc current by 90°
C. Leading the arc current by 90°
D. None of the above
2. Air break switches should be opened
A. Before the circuit breaker has opened the
circuit
B. After the circuit breaker has opened the
circuit
C. Along with the circuit breaker
D. None of the above
3. For 220 kV electric power line the circuitbreaker
performed is
A. Air blast CB
B. BOCB
C. Vaccum CB
D. AB switch
4. A material for good magnetic memory should
have
A. Low hysteresis los
B. High permeability
C. High retentivity
D. Low retentivity
5. A capacitor is generally a
A. Bi-lateral and active component
B. Active, linear and non-linear component
C. Linear and bi-lateral component
D. Non-linear and active component
6. Which of the following is the disadvantage due to
low power factor
A. High cost of equipment for a given load
B. Poor voltage regulation
C. Increased transmission losses
D. All the above
7. In railway applications which of the following
circuit breaker is used
A. SF6
B. Air break
C. Minimum oil
D. Bulk oil
8. Large internal faults are protected by
A. Merz price percentage differential protection
B. mho and ohm relays
C. horn gaps and temperature relays
D. earth fault and positive sequence relays
9. I n generating station the voltage adopted for an
alternator can be
A. 104.15 kv
B. 33 kv
C. 132 kv
D. 400 kv
10. A buchholz relay can be installed on
A. Auto-transformers
B. Air-cooled transformers
C. Welding transformers
D. Oil cooled transformers
11. In nuclear stations the fuel used is
A. Coal
B. Thorium
C. Water
D. Gas
12. Gilbert is a unit of
A. Magneto motive force
B. Electromotive force
C. Conductance
D. Permittivity
13. The concept on which super position theorem is
based on
A. Reciprocity
B. Duality
C. Non-linearity
D. Linearity
14. For all circuit breakers the temperature of the
oil and the breaker contacts should not exceed
A. 35 to 45°C
B. 60 to 70°C
C. 70 to 80°C
D. 80 to 90°C
15. A crack in the magnetic path of a inductor will
result in
A. Reduced inductance
B. Zero inductance
C. Un changed inductance
D. Increased inductance
16. A device prevents the oscillation of the moving
system and enables the latter to reach its final
position quickly
A. Deflecting
B. Controlling
C. Damping
D. Any of the above
17. Which of the motors have almost speed over
their full load range
A. AC series motor
B. DC series motor
C. DC shunt motor
D. Squirrel cage motors
18. A moving iron instrument can be used for
A. D.C. only
B. A.C. only
C. Current measurement only
D. Both D.C. and A.C.
19. The household energy meter is
A. An indicating instrument
B. A recording instrument
C. An integrating instrument
D. None of the above
20. …… relay is preferred for phase fault on short
transmission line
A. Induction type
B. Reactance
C. Impendence
D. None of the above
21. The material foe armouring on cable is usually
A. Steel tape
B. Galvanized steel wire
C. Any of the above
D. None of the above
22. Short circuit currents are due to
A. Single phase to ground faults
B. Phase to phase faults
C. Two phase to ground fault
D. Any of the above
23. Copper as conductor for cables is used as
A. Annealed
B. Hardened and tempered
C. Hard drawn
D. Alloy with chromium
24. Which of the parameter can be neglected for
short line
A. Inductance
B. Capacitance
C. Resistance
D. Reactance
25. In thermo couples which of the following pairs
is commonly used
A. Copper-constantan
B. Alumina-tin
C. Silver-German silver
D. Iron-steel
26. Arc is a circuit breaker is interrupted at
A. Zero current
B. Maximum current
C. ’minimum voltage
D. Maximum voltage
27. A pure semi conductor under ordinary
conditions behaves like
A. A conductor
B. An insulator
C. A magnetic material
D. None of the above
28. A fuse in a motor circuit provides protection
against
A. Over load
B. Short circuit and overload
C. Open circuit
D. None of the above
29. Thermistors find use in which of the following
A. In thermometry
B. In measurement of microwave power
C. As a thermal relay
D. All of the above
30. Laminations of armature core are generally
made of
A. Cast iron
B. Carbon
C. Silicon steel
D. Stainless steel
31. If the speed of a D.C. shunt motor is increased
the back emf of the motor will
A. Decrease
B. Increase
C. Remain same
D. Becomes zero
32. In lap winding the number of brushes is always
A. Double the number of poles
B. Same as the number of poles
C. Half of the number of poles’
D. Two
33. The purpose of providing dummy cols in a D.C.
generator is
A. T o enhance flux density
B. To amplify voltage
C. To provide mechanical balance for the rotor
D. To reduce eddy current
34. Resistance can be measured with the help of
A. Watt meters
B. Voltmeters
C. Ammeters
D. Ohm meters and resistance bridges
35. Compensating windings are used in D.C.
generators
A. Mainly to reduce the eddy currents
B. To provide path for the circulation of cooling
air
C. To neutralize the cross-magnetizing effect of
the armature reaction
D. None of the above
36. No-load speed of the which of the following
motor will be highest
A. Shunt motor
B. Series motor
C. Cumulative compound motor
D. Differential compound motor
37. In a portable instrument, the controlling torque
is provided by
A. Spring
B. Gravity
C. Eddy currents
D. All of the above
38. Small D.C. motors upto 5 H.P. usually have
A. 2 poles
B. 4 poles
C. 8 poles
D. 6 poles
39. A 220 V D.C. generator is running at full speed
without any excitation the open circuit voltage will
be
A. Zero
B. About 2 V
C. About 50 V
D. 220 V
40. The period of sine wave is 1/50 seconds .its
frequency is
A. 20 Hz
B. 30 Hz
C. 50 Hz
D. 500 Hz
41. A circuit breaker under normal conditions
should be inspected
A. Every day
B. Every week
C. Every month
D. Once in 6 months or 12 months
42. Fuse rating is expressed in terms of
A. Current
B. Voltage
C. kVA
D. kVAR
43. Di-electric strength is expressed in
A. kV/mm
B. kV/mm²
C. kV/mm³
D. v/ampere
44. The permeability of iron is around
A. 500
B. 800
C. 1200
D. 2000
45. Pressure cables are generally not used beyond
A. 11 kV
B. 33 kV
C. 66 kV
D. 110 kV
46. Curie temperature is the temperature above which
ferro- magnetic material becomes
A. Paramagnetic
B. Diamagnetic
C. either of the above
D. both of the above
47. Power lighting in passanger coach, in a long distance
electric train is provided
A. Directly through overhead electric line
B. Through individual generator of bogie and
batteries
C. Through rails
D. Through locomotives
48. A mercury vapour lamp gives --------------------- light
A. White
B. Pink
C. Yellow
D. Greenish blue
49. Which has the first city in india to adopt electric
traction
A. Delhi
B. Madrass
C. Calcutta
D. bombay