An electric bulb of 60 W is used for 6 h per day. Calculate the ‘units’ of energy consumed in one day by the bulb.

Solution:
Power of electric bulb = 60 W
= 0.06 kW.
Time used, t = 6 h
Energy = power × time taken
= 0.06 kW × 6 h
= 0.36 kW h
= 0.36 ‘units’.
The energy consumed by the bulb is 0.36 ‘units’.