Question

Pls help me in the question no. 10 with full explanation

Answer 1

Question :-

An electrician puts a fuse of rating 5A, in that part of domestic heater electrical circuit in which an electric heater of rating 1.5 kW, 220V is operating. What is likely to happen in this case and why? What change (if any) should be made?

Given :-

Fuse rating = 5A

V = 220V

P = 1.5 kW

1.5 kW = 1000 x 1.5 V

= 1500V

We know that,

P = V/I

Or,

I = P/V

Substituting values,

I = 1500/220

I = 6.8A

•°• A current of 6.8A flows through the circuit.

We are given that the fuse rating is 5A, and in this case, a current of 6.8A flows through the circuit. Therefore the temperature of the fuse wire increases which melts the fuse and breaks the circuit.

What changes should be made?

A fuse of 10A should be used, to prevent breaking of circuit.