Question

An electric iron is rated $\text{220V, 2kW}$. Why is the fuse absolutely necessary in a power circuit?

Answer 1

Hint: The purpose of a fuse in a circuit is to limit the amount of current flowing in a circuit. If the current goes above a certain value in the circuit then the fuse blows up, breaking the circuit and saving the appliances connected in that circuit.

Complete step-by-step answer:
First of all let us very clearly know what a fuse actually is and what its use is.
Definition- A fuse is an electrical safety device that operates to provide protection against overcurrent in an electrical circuit.
The component used in a fuse is a metal wire or strip that melts when too much current flows through it, thereby stopping or interrupting the current. Fuses have been used as an electrical safety device since a very long period of time. So, if we want to look into the reason that as to why fuse is important for an electrical circuit, the reason is that when there is an overflow of current across the circuit then the fuse is blown off automatically by melting and as a result, the power circuit goes off an dour appliance remains safe from any damage.
A fuse is also referred to as an automatic means of removing power from a faulty system; often abbreviated to ADS (Automatic Disconnection of Supply).
So, it can be concluded that a fuse is necessary in a circuit to save the circuit from any damage and hence also keep the surrounding safe.

Note: The time taken by the fuse to blow off or the speed at which the fuse blows off depends upon the current flowing through the circuit. It also depends on the material of which the fuse is made. The operating time of the fuse decreases as the current increases.