Question

Why we need a $5A$ fuse for an electric iron which consumes $1\mathrm{kW}$ power at $220V$?

Answer 1

Step 1: Given data

Voltage, $V=220volts$

Power, $P=1\mathrm{kW}\mathrm{or}1000\mathrm{W}$

Fuse current, $I=5A$

Step 2: To find

We have to find the current in the circuit.

Step 2: Finding current in the circuit.

As we know,

$P=VI$

$$\begin{gathered} \Rightarrow 1000=220\times I \\ \Rightarrow I=4.54\mathrm{A} \end{gathered}$$

The maximum current drawn by electric iron is 4.54 A so we should use a fuse of current capacity greater than the maximum current drawn.

Hence, we can use a $5A$ fuse for an electric iron.