1000+ Electrical Machines Multiple Choice Questions and Answers Pdf - 1

Question: 1

With the increase in speed of a DC motor

(A) back emf increases but line current falls

(B) both back emf as well as line current fall

(C) both back emf as well as line current increase

(D) back emf falls and line current increases

Question: 2

The armature of DC motor is laminated

(A) to reduce the hysteresis loss

(B) to reduce the eddy current loss

(C) to reduce the inductor

(D) to reduce the mass

Question: 3

The principle of operation of a 3 phase induction motor is most similar to that of a

(A) capacitor star induction motor

(B) repulsion star induction motor

(C) synchronous motor

(D) transformer with a shorted secondary

Question: 4

The power factor of a lightly loaded induction motor is quite low because

(A) the current drawn is largely magnetising current due to air gap

(B) the current drawn is largely an energy component due to laminated core

(C) the current drawn in largely a magnetizing component due to laminated core

(D) of the current due to air gap

Question: 5

Armature circuit resistance control method controls the speed of dc machines

(A) above base speed only

(B) both above and below base speed

(C) either above or below base speed

(D) below base speed only