The bearings used to support the rotor shafts are generally______________?

A separately excited generator as compared to a self-excited generator_____________?

A. is amenable to better voltage control

B. is more stable

C. has exciting current independent of load current

D. has all above features

In a four-pole D.C. machine____________?

A. all the four poles are north poles

B. alternate poles are north and south

C. all the four poles are south poles

D. two north poles follow two south poles

In lap winding, the number of brushes is always_____________?

A. double the number of poles

B. same as the number of poles

C. half the number of poles

D. two

In D.C. generators, the cause of rapid brush wear may be___________?

A. severe sparking

B. rough commutator surface

C. imperfect contact

D. any of the above

For a D.C. generator when the number of poles and the number of armature conductors is fixed, then which winding will give the higher e.m.f___________ ?

A. Lap winding

B. Wave winding

C. Either of A. and B. above

D. Depends on other features of design