Questions and answers for exam Preparation

MCQs

Total Questions : 377 | Page 32 of 38 pages

Question 311. Compensating windings are used in D.C. generators______________?

mainly to reduce the eddy currents by providing local short-circuits
to provide path for the circulation of cooling air
to neutralise the cross-magnetising effect of the armature reaction
none of the above

Discuss Question

Answer: Option C. -> to neutralise the cross-magnetising effect of the armature reaction
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 312. Number of tappings for each equalizer ring is equal to_____________?

number of pole pairs
number of poles
number of parallel paths
number of commutator segments

Discuss Question

Answer: Option A. -> number of pole pairs
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 313. The voltage drop for which of the following types of brush can be expected to be least ?

Graphite brushes
Carbon brushes
Metal graphite brushes
None of the above

Discuss Question

Answer: Option C. -> Metal graphite brushes
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 314. Two generators A and B have 6-poles each. Generator A has wave wound armature while generator B has lap wound armature. The ratio of the induced e.m.f. is generator A and B will be_______________?

2 : 3
3 : 1
3 : 2
1 : 3

Discuss Question

Answer: Option B. -> 3 : 1
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 315. In D.C. generators, lap winding is used for______________?

high voltage, high current
low voltage, high current
high voltage, low current
low voltage, low current

Discuss Question

Answer: Option B. -> low voltage, high current
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 316. A D.C. generator can be considered as____________?

rectifier
primemover
rotating amplifier
power pump

Discuss Question

Answer: Option C. -> rotating amplifier
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 317. In a D.C. machine stray loss is the sum of_____________?

total copper loss and mechanical loss
armature copper loss and iron loss
shunt field copper loss and mechanical loss
iron loss and mechanical loss

Discuss Question

Answer: Option D. -> iron loss and mechanical loss
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 318. In any rotating machine that part which houses the conductors and in which e.m.f. induced is to be utilized is called____________?

rotor
stator
field
armature

Discuss Question

Answer: Option D. -> armature
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 319. The armature core of a D.C. generator is usually made of__________________?

silicon steel
copper
non-ferrous material
cast-iron

Discuss Question

Answer: Option A. -> silicon steel
NO EXPLANATION IS AVAILABLE FOR THIS QUESTION!

Question 320. The e.m.f. generated by a shunt wound D.C. generator isE. Now while pole flux remains constant, if the speed of the generator is doubled, the e.m.f. generated will be_______________?