Which one of the following is an essential component of electromechanical relays?

Question

Question

This question was previously asked in

IPRC (ISRO) Technician B (Electronic Mechanic): Previous Year Paper (Held on 10 Dec 2016)

Answer 1

Electromechanical relay:

These relays were the earliest forms of relay used for the protection of the power system from abnormal conditions.
The heart of a relay is an electromagnet (a coil of wire that becomes a temporary magnet when electricity flows through it)
These work on the principle of mechanical force causing an operation of the relay.
Basically, there are two different operating principles of relays namely electromagnetic attraction and electromagnetic induction.