Question

Calculate the cost of operating a heater of 500Watt for 20Hours at the rate of Rs.3.90 per unit.

Answer 1

1 unit = 1 KWh =3.6×10^6
energy consumed by heater = (500/1000)20
= 10 KWh =10 unit
cost of 10 units = 3.90 ×10 = 39