Question

An electric kettle consumes 1 KW of electric power when operated at 220 V. A fuse wire of what rating must be used for it?
Availability of the fuses are 2A, 4A, 5A.

Answer 1

Given:
Power, P= 1 KW = 1000 W
Voltage, V = 220V
P = V I
$\Rightarrow 1000=220\times I$
$\Rightarrow I=\frac{1000}{220}=4.54A$

As we have only 2A, 4A and 5 A fuse.
Rating of the fuse to be used should be slightly more than the current flowing through it, hence the fuse will be of 5 A.