Question

Why are relays used for driving the motors?

(a) they can be used as switch as well as they provide isolation

(b) they increase the current capability required by the motors

(c) they are used to reduce the back emf from the motors

(d) all of the mentioned

I got this question in exam.

Question is taken from Interfacing with Motors in division AVR Microcontroller of Microcontroller

Answer 1

Correct answer is (a) they can be used as switch as well as they provide isolation

Explanation: Relay is the electrically controlled switch and it allows isolation of two separate sections of the system. It has three main components: the coil, the common pole and the contacts. When an electric field is applied to the coil; it gets energized and generates a magnetic field which will force the common pole to change contact from Normally Closed to Normally Open.