Heating effect of electric current is not observed in ______________.(A) Electric oven(B) Electric iron(C) Electric motor(D) Fuse

The correct answer is (D) Fuse.

The heating effect of electric current, also known as Joule heating, is observed in devices where the electrical energy is converted into heat energy. In options (A), (B), and (C), electric current is intentionally used to generate heat:

Electric oven: An electric oven uses electrical energy to produce heat for cooking or baking purposes.
Electric iron: An electric iron uses electrical energy to generate heat, which is then used to remove wrinkles from clothes.
Electric motor: An electric motor converts electrical energy into mechanical energy, and as a result, it generates heat due to various factors such as friction and resistance.
On the other hand, a fuse is a safety device used in electrical circuits to protect against excessive current flow. It contains a thin wire that melts when there is a high current, thus breaking the circuit and preventing damage to other components. The primary purpose of a fuse is not to generate heat but to provide protection against electrical faults. Therefore, the heating effect of electric current is not observed in a fuse.