1000+ Electrical Machines Multiple Choice Questions and Answers Pdf - 2

Question: 6

Wave winding is preferred for which of the following rating?

(A) low current and high voltage

(B) high current and low voltage

(C) high current and high voltage

(D) low current and low voltage

Question: 7

The mechanical power is developed by a DC motor is maximum when

(A) back emf is equal to applied voltage

(B) back emf is equal to twice of applied voltage

(C) back emf is equal to half of applied voltage

(D) none of the above

Question: 8

A synchronous motor is operating on no-load at unity power factor. If the field current is increased, the pf will become

(A) leading and the current will decrease

(B) leading and the current will increase

(C) lagging and the current will increase

(D) leading and the current will decrease

Question: 9

Commutator in DC generator is used for

(A) increase efficiency

(B) reduces losses

(C) convert AC armature current in to DC

(D) collection of current

Question: 10

The full load voltage regulation of a power transformer is zero when power factor of the load is near

(A) unity and leading

(B) zero and lagging

(C) unity and lagging

(D) zero and leading