Question

Why is the back EMF used in DC motors?

Answer 1

Back emf is used in DC motors;

1. When the armature rotates under the influence of driving torque in the DC motor, the armature moves through a magnetic field inducing emf in them.
2. The induced emf is in the opposite direction to the applied voltage then it is known as the back emf.
3. It is used in DC motors because this energy conversion is possible in the DC motor and it makes a DC motor self-regulating.
4. The diagram given below shows the back emf in the DC motor;