1000+ Synchronous Motors MCQ Questions and Answers - 2

Question: 6

The operating speed of a synchronous motor can be changed to new fixed value by

(A) using brakes

(B) changing frequency

(C) changing the supply voltage

(D) changing the load

Question: 7

A synchronous motor can develop synchronous torque

(A) below or above synchronous speed

(B) when under loaded

(C) while over excited

(D) only at synchronous speed

Question: 8

For V-curves for a synchronous motor the graph is drawn between

(A) armature current and power factor

(B) power factor and field current

(C) terminal voltage and load factor

(D) field current and armature current

Question: 9

The shaft of synchronous motor is made of

(A) stainless steel

(B) alnico

(C) chrome steel

(D) mild steel

Question: 10

Synchronous motors are generally not self starting because

(A) starting winding is not provided on the machines

(B) starters cannot be used on these machines

(C) the direction of instantaneous torque reverses after half cycle

(D) the direction of rotation is not fixed