Question

An electric bulb of rating $\text{50W}$ is used for $\text{8hr}$ in one day. Find the number of units $\left(kWh\right)$ of energy used by the electric bulb.

• A. 200 unit
• B. 0.4 unit
• C. 0.6 unit
• D. 400 unit

Answer 1

The correct option is B

0.4 unit

$\text{50 W = 0.05 kW}$
$So,power=0.05kW\times 8h$
$=0.4kWh=0.4unit$