Question

Calculate the total cost of running the following electrical devices in the month of September, if the rate of 1 unit of electricity is ₹6.00.
(i) Electric heater of 1000 W for 5 hours daily.
(ii) Electric refrigerator of 400 W for 10 hours daily.

Answer 1

Energy consumed by electric heater = P ` xx ` time = 1000 W ` xx ` 5h = 5000 Wh
(ii) Energy consumed by refrigerator = P ` xx ` time = `400 xx 10 ` = 4000 Wh
Total energy consumed in one day = 5000 Wh + 4000 Wh
= 9000 Wh = `9000/1000` kWh= 9 kWh
Total energy consumed in the month of september = `30 xx 9 = 270 ` kWh = 270 unit
Cost of 1 unit of electricity = ₹6 ` therefore ` Cost of 270 unit of electricity = ` ₹ 6 xx 270 = ₹ 1,620`