Question

In a household electric circuit different appliances are connected in parallel to one another. Give two reasons.

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

Answer 1

In a household electric circuit different appliances are connected in parallel to one another so that:

(i) The appliances can be operated independently.
(ii) They get the same applied voltage.


We know that power, $P=VI$

Now, the current flowing through the circuit will be, $I=\frac{P}{V}$

Here, P = 1.5 kW = 1500 W

V = 220 volts

So, $I=\frac{1500}{220}=6.81\text{A}$

As we can see the current flowing the circuit is more than the maximum current rating of the fuse. This means, that the fuse will blow (or melt) and the circuit will break. Therefore, no current will flow further in the circuit.