Question

An electric bulb of $30W$ consumes $0.72$ units of energy in a day. Find the number of hours it is working in a day?

• A. $6hrs$
• B. $12hrs$
• C. $18hrs$
• D. $24hrs$

Answer 1

The correct option is D $24hrs$

Given : $P=\frac{30}{1000}=0.03kWh$

Energy consumed per day $E=0.72\text{units}$$=0.72kWh(As1unit=1kWh)$

Using $E=P\times t$

$\therefore$ $0.72=0.03\times t$

$⟹t=24hrs$