Question

an electric bulb of 40w Glows for 10 hours a day. what is the amount to be paid in a month of 30 days,if 1 unit of electricity costs Rs 2.50?

Answer 1

1 unit = 1kwh and total energy consumption is = power × time

Answer 2

Consumer pays Rs. 30 at the end of month.

Explanation:

Bulb Rating = 40 Watts

Hours it glowed = 10 hours

So electricity consumption per day = 40 * 10 = 400 watts.

Electricity consumption for 30 days = 400 * 30 = 12000 watts.

Number of units consumed = 12000 / 1000 = 12 Kw or 12 units.

Cost per unit = Rs. 2.50

Electricity bill for 30 days = 12 * 2.50 = Rs. 30