Draw a labelled diagram of a magnetic relay and explain it's working

Relay is a controlling device just like a switch. handling high current with smaller current is the function of the relay.

Explanation:

There is a coil with the iron core is used as an electromagnet to operate the contact switch. When the control switch is closed the magnet operates the contact closed by attracting the metal terminal of the contacts switch. then current will passed throw the contact switch to load. When the control switch is open, the magnetic force will release and open the contact switch.

In a lot of applications, these replays are used to operate to control high current. it can control both AC and DC, but the magnetic coil works only dc.

wavelength divides in half and speed stays the same.