Question

Explain the working of fuse in electric circuit
An electrician puts a fuse of rating 5A in the kitchen of a house where an electric oven of 2.2Kw ; 220 V operates .What is likely to happen in this case and why ? Suggest a change , if any , needs to be made.

Answer 1

Dear student

Fuse is a safety device used to stop overloading and short-circuiting. Fuse is made up of, generally, alloys which have low melting point and breaks when over current is passed according to Joule's law of heating.

2nd part
we know that

P = VI

now, the current flowing through the circuit will be

I = P / V

here,

P = 2.2 kW =2200 W

V = 220 volts

so,

I = 2200 / 220

thus,

I = 10A

Now, current the rating of the fuse (= 5A) is less than the current flowing (= 10A) in the circuit. This wold mean that the fuse will blow (or melt) and the circuit will shut down, not allowing further current to flow.

The electrician should use a fuse of 15A or 20A to prevent this.

Regards