1000+ Electrical Machines Objective Questions and Answers Pdf - 2

Question: 6

Variation in speed by ward Leonard control of DC motors occurs due to variation in

(A) armature current

(B) field excitation

(C) supply voltage

(D) armature voltage

Question: 7

The induced emf in the armature conductors of a dc motor is

(A) alternating

(B) rectangular

(C) trapezoidal

(D) sinusoidal

Question: 8

The current from the stator of an alternator is taken out to the external load circuit through

(A) carbon brushes

(B) slip rings

(C) solid connections

(D) commutator segments

Question: 9

The part of transformer which is subjected to maximum heating is

(A) frame

(B) core

(C) oil

(D) winding

Question: 10

The maximum efficiency of a dc machine is obtained when variable armature circuit loss is

(A) equal to iron loss

(B) equal to fixed loss

(C) equal to copper loss

(D) equal to core loss