1. . When a conductor cuts magnetic flux, e.m.f induces in it, by:
(A) Coulomb’s law
(B) Faraday’s Law
(C) Lenz’s law
(D) Joule’s law
2. . DC generator works on ___ principle:
(A) Faraday’s law
(B) Coulomb’s Law
(C) Lenz’s law
(D) Joule’s law
3. . The salient-pole construction for field structure of an alternator is generally used for ……….machine.
(A) 4 pole
(B) 2 Pole
(C) 6 Pole
(D) 8 Pole
4. . A 10 pole AC generator rotates at 1200 rpm. The frequency of AC voltage in cycles second will be:
(A) 120
(B) 60
(C) 160
(D) 100
5. . The e.m.f induced in the dc generator armature winding is:
(A) AC
(B) DC
(C) AC and DC
(D) None of the above
6. . Commutator in DC generator is used for:
(A) Collecting of current
(B) Reduce losses
(C) Increase efficiency
(D) Convert AC armature current into DC
7. . A DC generator without commutator is a:
(A) AC generator
(B) DC motor
(C) DC generator
(D) Induction motor
8. . In DC machine yoke offers:
(A) Mechanical protection to the machine
(B) Flux path completion
(C) Produce working flux
(D) Both A and B
9. . Which of the following bearings and their uses are correct?
(A) Ball bearings → small machines
(B) Roller bearings → large machines
(C) Neither a nor b
(D) Both a and b
10. . A transformer is designed to be operated on both 50 & 60 Hz frequency. For the same rating, which one will give more output; when:
(A) Operates on 50 Hz
(B) Operates on 60 Hz
(C) Neither a nor b
(D) None of these
11. . A Step-Up Transformer which has 110/220 turns. What would happen if we replace it with 10/20 turns? (Because Turns ratio would be same in both cases)
(A) Induced E.M.F would be same
(B) Induced E.M.F would be decreased
(C) Neither a nor b
(D) None of these
12. . The rating of transformer may be expressed in ____________.
(A) KW
(B) KVAR
(C) KVA
(D) Horse power
13. . What will happen if the primary of a transformer is connected to D.C supply?
(A) Transformer will operate with low efficiency
(B) Transformer will operate with high efficiency
(C) No effect
(D) Transformer may start to smoke and burn
14. . A Step Up transformer _____________.
(A) Step Up the level of Voltage
(B) Step down the level of current
(C) Step up level the power
(D) Step up the level of Frequency
15. . In Single Phase Transformer, The Primary Current and Primary Voltage is 4.55 and 11kV respectively. The Rating of the transformer would be________?
(A) 50kVA
(B) 86kVA
(C) 100kVA
(D) 150kV
16. . In a split phase motor, the running winding should have:
(A) High resistance and low inductance
(B) High resistance and High inductance
(C) Low resistance and high inductance
(D) Low resistance and Low inductance
17. . If the capacitor of a single-phase motor is short-circuited:
(A) The motor will not start
(B) The motor will run in the same direction at reduced speed
(C) The motor will run in reverse direction
(D) None of the above
18. . In a split phase motor:
(A) Both starting and running windings are connected through a centrifugal switch
(B) Centrifugal switch is used to control supply voltage
(C) The running winding is connected through a centrifugal switch
(D) The starting winding is connected through a centrifugal switch
19. . The torque developed by a single-phase motor at starting is:
(A) Less than the rated torque
(B) More than the rated torque
(C) Zero
(D) None of the above
20. . In a capacitor start and run motors the function of the running capacitor in series with the auxiliary winding is to:
(A) Improve power factor
(B) Reduce fluctuations in torque
(C) Increase over-load capacity
(D) To improve torque
21. . In repulsion motor direction of rotation of motor:
(A) Same as that of brush shift
(B) Independent of brush shift
(C) Opposite to that of brush shift
(D) None of the above
22. . If a particular application needs high-speed and high starting torque, then which of the following motor will be preferred?
(A) Shaded pole motor
(B) Capacitor start motor
(C) Capacitor run motor
(D) Universal Motor
23. . Which of the following motor is used in the mixer?
(A) Repulsion Motor
(B) Reluctance Motor
(C) Hysteresis Motor
(D) Universal Motor