Question

31. The nutrients value of sweet is 360 kcal. The energy
from it will be sufficient to light a bulb of 100 W for
how much time?
(a) 1 h
(b) 2 h
(c) 4 h and 12 min
(d) 4 h and 2 min​

Answer 1

Explanation:

Energy is the product of power and time:

E = P×T = (100W)×(10h) = (100W)×(36000s)

This gives us 1 kilowatt hour, or 3.6 megajoules.

If you're looking for the amount of electrons (in Coulombs) which have passed through the bulb, simply divide the energy by the voltage.