Answer:
A relay is a kind of electrical switch which interconnects an electric circuit. It works using an electromagnet which makes or breaks a contact when a voltage is applied to the coil. It is activated immediately when voltage is applied. In a relay delay, the electromagnet is not energized instantaneously when a voltage is applied. It is activated after a fixed set of time or programmed time.Various types of delay mechanism are available, some fixed, some with variable time delay. The timing mechanism can be mechanical, motorized or electronic.