Question

3 bulbs of 40 w for 6 hours

Answer 1

3 bulbs of 40 w runned for 6 hours uses =3*40*6=720watt=0.72kw

Answer 2

energy = number of bulbs * power consumed by each bulb * time.
= 3*40*$10^{3}$*6.
= 0.72 kWh

the same value in joules
E= 0.72* 3.6*$10^{6}$.
= 2592*$10^{3}$    J.

where 3.6*$10^{6}$ joules is = 1kWh which is called as commercial unit of energy.



hope this helps. pls mrk as brainliest.............