Correct option is A
· A bimetallic thermal overload relay operates based on the principle of thermal expansion of metals.
· It consists of two different metals with different coefficients of thermal expansion bonded together.
· When the temperature rises due to excessive current, the metals expand at different rates, causing the bimetallic strip to bend.
· This bending action can be used to open or close electrical contacts, thus protecting the circuit from overload.
· Given this explanation, a bimetallic thermal overload relay is an example of a temperature sensing device.
