DC Motors When the armature of a D.C. motor rotates, e.m.f. induced is Mutually induced e.m.f. None of these Self-induced e.m.f. Back e.m.f. Mutually induced e.m.f. None of these Self-induced e.m.f. Back e.m.f. ANSWER DOWNLOAD EXAMIANS APP
DC Motors The back emf in a dc motor ______ Opposes the applied voltage Aids the armature current None of the listed here Aids the applied voltage Opposes the applied voltage Aids the armature current None of the listed here Aids the applied voltage ANSWER DOWNLOAD EXAMIANS APP
DC Motors In D.C. machines the residual magnetism is of the order of 10 to 15 percent 2 to 3 percent 20 to 25 percent 50 to 75 percent 10 to 15 percent 2 to 3 percent 20 to 25 percent 50 to 75 percent ANSWER DOWNLOAD EXAMIANS APP
DC Motors The direction of rotation of a D.C. series motor can be changed by Interchanging supply terminals Either of (A) and (B) above None of these Interchanging field terminals Interchanging supply terminals Either of (A) and (B) above None of these Interchanging field terminals ANSWER DOWNLOAD EXAMIANS APP
DC Motors The speed of a series motor at no load is Infinity 1000 rpm 4000 rpm 2000 rpm Infinity 1000 rpm 4000 rpm 2000 rpm ANSWER DOWNLOAD EXAMIANS APP
DC Motors Where D.C. motor of H.P. 12 or more requires frequent starting, stopping, reversing and speed control Three point starter is used Drum type controller is used Four point starter is used All above can be used Three point starter is used Drum type controller is used Four point starter is used All above can be used ANSWER DOWNLOAD EXAMIANS APP