Question

a) Mention the lines to which the heating coil of an electric iron is connected.
b) Explain how a three pin plug ensures safety when it is used with an electric iron.

Answer 1

a) One end of the heating coil is connected to the phase line and the other end to the neutral line.
b) When a three pin plug is used, the body of the iron is connected to the third thick pin (Earth). Hence, when the phase line accidentally comes in contact with the metallic case, the current will flow towards the earth through the earth line. Since, the resistance of the circuit is low, the flow of current will be greater causing the fuse to melt off resulting in the current in the circuit being cut off thereby protecting human life.