Question

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

Answer 1

Hint: Heating effect of electric current is observed when the current passes through a coil with high resistance, this resistance converts the electrical energy into heat energy. The devices which utilize this heating effect of electric current are generally made from high resistance wires/ plates or coils.

Complete step by step solution:
The working principles of these devices are discussed below-
Electric oven- In an electric oven, a few coils made from resistive alloys are arranged in such a fashion that they surround the food and cook it.
Electric iron- An electric iron has a coil made from nichrome inside it, this wire heats up when the current is passed through it and in turn also heats up the outer surface of the electric iron which is used to press clothes.
Electric motor- An electric motor uses the principle of electromagnetism, it contains a magnetic core that interacts with the electric field passing through the wire to produce a torque that rotates the shaft of the motor. It converts electrical energy into mechanical energy.
Fuse- A fuse is a system made from a conductive wire which has a low melting point, when the electric current passes through the wire it raises the temperature of the fuse, if the current exceeds its desired value, the wire gets overheated and melts down and the circuit is broken, this prevents any fire hazard or damage of any electrical equipment.
Thus, it is clear that the heating effect of electric current is not observed in the functioning of an electric motor.

Hence, Option (C) is correct.

Note: The heating effect of electric current is practically observed in every circuit because there is always some amount of resistance present when the current flows. But in most of the cases the heating produced is not significant and the energy spent in this process is considered as a loss.