Question

Differentiate between short circuiting and overloading of the electric circuits? How does a fuse protect an electric current?

Answer 1

Short circuiting:

Short circuiting occurs when naked live and neutral wires touch each other. In such a case, the resistance of the circuit becomes very less. Now, according to Ohm’s law, current is inversely proportional to resistance. Thus, the lowering of resistance of the circuit raises the current to a significant amount. As a result, the wires become hot and a spark is caused by Joule’s heating effect of current. This situation is known as short circuiting.

Overloading:

A large amount of current is withdrawn from the circuit, when a large number of electrical appliances of high power-rating are switched on at the same time or connected in a single multi-plug. This situation is called overloading.

A fuse (short for fusible link) is a type of over current protection device. Its essential component is a metal wire or strip that melts when too much current flows, which breaks the circuit in which it is connected, thus protecting the circuit's other components from damage due to excessive current.Fuses (and other overcurrent devices) are an essential part of a power distribution system to prevent fire or damage. When too much current flows through a wire, it may overheat and be damaged, or even start a fire. Wiring regulations give the maximum rating of a fuse for protection of a particular circuit.