Electric fuse is a safety component connected in series with an electric circuit which provides protection to electric devices and appliances from excess current.
Power consumption of electric heater is 3kW = 3000W
V = 220V
I = 5A
We know, P = VI
= 220 x 5
= 1100W
Thus, maximum power that can be drawn from the circuit is 1100W.
Thus, If the electric heater is connected to the circuit and switched "ON", the circuit will get overloaded and fuse will be blown out.