Question

What's a bimetallic strip?

Answer 1

Hint : An electrical device is formed of two separate strips of metal stuck together. These two strips expand to a special extent when heated. So, when the strip is heated, one strip is going to be longer than the opposite. Therefore, the electrical device will bend.

Complete Step By Step Answer:
An electrical device is employed to convert a natural process into mechanical displacement. The strip consists of two strips of various metals which expand at different rates as they're heated.
The different expansions force the flat strip to bend a method if heated, and within the other way if cooled below its initial temperature. The metal with the upper coefficient of thermal expansion is on the outer side of the curve when the strip is heated and on the inner side when cooled.
Bimetal strips are utilized in miniature circuit breakers to guard circuits from excess current. A coil of wire is employed to heat a bimetal strip, which bends and operates a linkage that unlatches a spring-operated contact. This interrupts the circuit and may be reset when the bimetal strip has cooled down.
The invention of the electrical device is usually credited to John Harrison, an eighteenth-century clockmaker who made it for his third marine chronometer (H3) of 1759 to catch up on temperature-induced changes within the balance spring.

Note :
Bimetal strips also are utilized in time-delay relays, gas oven safety valves, thermal flashers for older blinker lamps, and lamp starters. In some devices, the present running directly through the bimetal strip is sufficient to heat it and operate contacts directly. It's also been utilized in mechanical PWM voltage regulators for automotive uses.