Electrical engineering Question Answers

Q No. 1. The bearings used to support the rotor shafts are generally
(a) ball bearings
(b) bush bearings
(c) magnetic bearmgs
(d) needle bearings
Ans: a

Q No. 2. Synchronizing torque comes into operation under all of the following cases EXCEPT

(A) phase difference between two voltages

(B) frequency difference between two voltages

(C) voltage difference between two voltages

(D) reduction in exciting current in one of the alternators.

Q No. 3. In case of a 4-pole D.C. generator provided with a two layer lap winding with sixteen
coils, the pole pitch will be
(a) 4
(b) 8
(c) 16
(d) 32
Ans: b

Q No. 4. Welding generator will have
(a) lap winding
(b) wave winding
(c) delta winding
(d) duplex wave winding
Ans: a

Q No. 5. Commonly used instruments in power system measurement are
(a) induction
(b) moving coil or iron
(c) rectifier
(d) electrostatic
Ans: a

Q No. 6. The demagnetising component of armature reaction in a D.C. generator
(a) reduces generator e.m.f.
(b) increases armature speed
(c) reduces interpoles flux density
(d) results in sparking trouble
Ans: a

Q No. 7. In order to achieve high accuracy, the slide wire of a potentiometer should be
(a) as long as possible
(b) as short as possible
(c) neither too small not too large
(d) very thick
Ans: a

Q No. 8. The armature core of a D.C. generator is usually made of
(a) silicon steel
(b) copper
(c) non-ferrous material
(d) cast-iron
Ans: a

Q No. 9. Which of the following is an essential part of a motor meter ?
(a) An operating torque system
(b) A braking device

(c) Revolution registering device
(d) All of the above
Ans: d

Q No. 10 Q.21 A hysteresis motor
(A) is not a self-starting motor.
(B) is a constant speed motor.
(C) needs dc excitation.
(D) can not be run in reverse speed.

Ans: B

Electrical engineering Question Answers

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