Electrical Machines Practice MCQ-1

Electrical Engineering Practice Test

Electrical Machines

1. the basic requirements of a d.c armature winding is that it must be

A) Closed one
B) a lap winding
C) a wave winding
D) either b) or c)

... Answer is A)
The Armature Winding Should be closed one to supply the current

2.A wave winding must go at least ___________ around the armature before it closes back wher it started

A once
B)twice
C)thrice
D)four times

... Answer is B)
the paralle pathe A=2 for wave wingding

4.The Solo Purpose of a Commutator in d.c. Genrator is to

A) Increase output voltage
B)reduce sparking at brushes
C)Provide smoother output
D)Convert the induced a.c. into d.c

... Answer is D)
The Commutator Conver the AC to DC in DC Generator

5.if in the case of a certain d.c armature the numebr of commuator segments is found either one less or more than the number of slots the armature must be having a simple _______________winding.

A)wave
B)lap
C)frogleg
D)multielement

... Answer is A)

6.The commerical Efficiency of a shunt Generator is maximum when its variable loss equalsto_____________loss

A) Constant
B)stray
C)iron
D)friction and windage

... Answer is A)

7.in a d.c genrator the genrator e.m.f is directly propotional to the

A) field flux
B)pole flux
C)number of armature parallel paths
D)number of dummy coils

... Answer is B)

8.The series field of ta short shunt d.c. Genrator is excited by _______ currnets

A)shunt
B)armature
C)load
D)external

... Answer is C)

9.In DC Genrator , armature reaction is produced actually by

A)its field curents
B)armature conductors
C)field pole winding
D)load current in armature

... Answer is D)

10.In a dc genrator the effect of armature reaction on the amain pole flux is to

A)reduce it
B)distort it
C)reverse it
D)bothe (a) and (b)

... Answer is D)