Alternators MCQs

Question 1

Generated e.m.f. for same field current and double speed will be

Accepted Answer

double

Answer

same

Answer

less than double

Answer

more than double

Question 2

If the space flux distribution is nonsinusoidal, e.m.f. induced in the distributed winding

Accepted Answer

will be more sinusoidal than flux distribution

Answer

will be less sinusoidal than flux distribution

Answer

will be equally non-sinusoidal

Answer

none of the above

Question 3

Voltage regulation obtained by synchronous impedance method is

Accepted Answer

more than that given by actual tests

Answer

equal to that given by actual tests

Answer

less than that given by actual tests

Answer

none of the above

Question 4

In an alternator short-circuit current is limited by

Accepted Answer

the unsaturated synchronous impedance

Answer

the saturated synchronous impedance

Answer

either of the above

Answer

none of the above

Question 5

In an alternator, armature reaction is considered equivalent to

Accepted Answer

fictutius reactance

Answer

fictitious impedance

Answer

fictitious conductance

Answer

fictitious resistance

Question 6

Synchronous impedance method gives more regulation as compared to ampereturn method because

Accepted Answer

armature reaction is considered negligible

Answer

saturation effect is ignored in the synchronous impedance

Answer

saturation effect is take into account in the synchronous impedance method

Answer

initial conditions are considered zero

Question 7

Leakage reactance of the armature of a salient pole synchronous machine which varies with the position of the rotor is due to

Accepted Answer

leakage flux which comes out of slot teeth, crosses the air gap and enters pole faces

Answer

leakage flux which remains withing the slot

Answer

leakage flux of end connections

Answer

none of the above

Question 8

Turbo-rotor is made up of

Accepted Answer

solid steel forging having milled slots for field winding

Answer

large spider to which laminated pole shoes are secured

Answer

laminations

Answer

none of the above

Question 9

A commercial alternator has

Accepted Answer

stationary armature and rotary field

Answer

rotating armature and stationary field

Answer

both armature and field rotary

Answer

both armature and field fixed