In case the back e.m.f. and the speed of a D.C. motor are doubled, the torque developed by the motor will
A. remain unchanged
B. reduce to one-fourth value
C. increase four folds
D. be doubled
Answer:A
In case the back e.m.f. and the speed of a D.C. motor are doubled, the torque developed by the motor will
A. remain unchanged B. reduce to one-fourth value C. increase four folds D. be doubled