Back Emf | MCQs

Explanation

Back e.m.f (electromotive force) is the voltage opposing the applied voltage, commonly seen in motors and inductive circuits.

When back e.m.f = 0, there is no opposing voltage, so the entire applied voltage appears across the circuit's resistance.

From Ohm's Law:

I=V−back e.m.f​/R

If back e.m.f = 0, then

I=V/R​(maximum possible current)

Explanation

Back e.m.f. is directly proportional to the speed of the motor.

As the motor speed increases, the back e.m.f. also increases.