Question

An electrical appliance has a rating of $5\text{kW}-200\text{V}$. What should be the minimum current rating of the fuse (in $\text{A}$) to be used with the appliance?

• A. 25

Answer 1

The correct option is A 25
A fuse wire is made so thin so that when current exceeds the rating of the fuse, it melts hence breaking the circuit.
Power, $\text{P}=\text{VI}$
For $\text{V}=200\text{V},\text{P}=5000\text{W}$ Given:
$\text{I}=\frac{\text{P}}{\text{V}}=25\text{A}$
So, the current rating of the fuse should be at least $25\text{A}$.