A living-room circuit protected by a 10 A miniature circuit breaker (MCB) supplies…
PHYSICS · Multi-part · CBSE · Physics · Magnetic Effects of Electric Current · Magnetic Effects of Electric Current
Problem
A living-room circuit protected by a 10 A miniature circuit breaker (MCB) supplies the following appliances:
• Electric iron: 1200 W
• Microwave oven: 800 W
• Ceiling fan: 150 W
• Four LED bulbs: 40 W each
(i) Calculate the total current that will be drawn from the 220 V mains when all the above appliances are switched on together.
(ii) State, with calculation, whether the 10 A MCB will trip under these conditions.
(iii) If the live wire accidentally comes in contact with the metallic body of the electric iron, explain how (a) earthing and (b) the MCB together protect the user from electric shock.
(iv) Suggest any two practical measures the householder can adopt to avoid over-loading this circuit in everyday use.