Question

An electric fuse of rating 3A is connected in a circuit in an electric iron of power 1kW which operates at 220V. What would happen?Explain.

Answer 1

Power= VI

Power = 1kW = 1000 W

I = p /v= 1000/220  = 4.54 A

So the fuse will melt and break down the current.

Answer 2

I= 3 A

P=1.kW=1000 W
V=220.V

P=VI, I=P/V
           =1000/220
           =4.5.A
3.A< 4.5.A
 hence the electric iron wont work.