Ask full question Similar question An electric refrigerator rated 400W operates 8 hours a day.What is the cost of energy to operate it for 30 days at Rs. 3:00 per kW h. Power P = 400 W Energy used = P x t = 400 W x 8 h x 30 = 96000 Wh = 96 kWh Cost of 1 kWh energy = Rs. 3.00 Cost of 96 kWh energy = 96 x 3 = Rs. 288