Question

An air-conditioner of 3.2 kW power rating is connected to a domestic electric circuit having a current rating of 10 A. The voltage of power supply is 220 V. What will happen this air-conditioner is switched on?
Explain your answer.

Answer 1

We will first calculate the current drawn by this air-conditioner.
Power, P = 3.2 kW = 3.2 $\times$ 1000 W = 3200 W
Potential difference, V = 220 V
We know:
Power, P = V $\times$ I
or, 3200 = 220 $\times$ I
or, current drawn, I = 14.5 A
Now, the current drawn by this air-conditioner is 14.5 A which is very high and the fuse in this circuit is of 10 A capacity.
So, when a very high current of 14.5 A flows through 10 A fuse, the fuse wire will get heated. Further, it will melt and break the circuit, thereby cutting off the power supply.
Therefore, when the given 3.2 kW power rating air-conditioner is switched on, the fuse will cut off the power supply in this circuit.