Question

An electric refrigerator rated 400W operates 8 hours per day. What is the cost of of energy to operate
it for 30 days at Rs. 3.00 per kWh?

Answer 1

Energy of one day = power × time = 400 W × 8h = 3.2 K W h

Energy of 30 days = 3.2 K W h × 30 = 96 K W h

So, the cost of the energy = 96 × 3 = Rs. 288