Question

Out of three fuses available, with a current ratings 5 A, 10 A, and 13 A, which one should be used in a circuit, containing a geyser, rated 3 kW-250 V? Give one reason.

Answer 1

Step 1- Given data

Power rating $P=3kW=3000W.$

Voltage (potential difference) $V=250V.$

Three available currents i.e $5A,10Aand13A.$

Step 2- To find out the feasible current in the fuse-

The formula for power delivered in the fuse is $P=V.I$

$\Rightarrow I=\frac{P}{V}$

$\Rightarrow I=\frac{3000}{250}=12A.$

Thus, the maximum current which can flow in the fuse without blowing it is $12A.$

Thus, Out of three fuses available, with current ratings $5A,10Aand13A$, the $13A$rated fuse should be used in a circuit.