# 5. How many kilowatt-hours of energy would be used by a 40 W bulb that runs for 10 hours every day during the course of one year

Question

5. How many kilowatt-hours of energy would be used by a 40 W bulb that runs for 10 hours every

day during the course of one year?

in progress 0
1 year 2021-08-29T20:29:41+00:00 1 Answers 21 views 0

E = 0.4 kWh

Explanation:

Given that,

The power of a bulb, P = 40 W

Time, t = 10 hours

We need to find the energy used by the bulb. Let it is equal to E. So,

$$E=P\times t\\\\E=40\times 10\\\\E=400\ W-h\\\\or\\\\E=0.4\ kWh$$

So, 0.4 kWh of energy would be needed.