Question

How many coulontos of charge move across a 120 V source when 1440 J of energy is

required?

Answer 1

The energy, voltage and charge are related as

$\Delta E = q\cdot \Delta V \\ \text{} \\ \therefore q = \frac{\Delta E }{ \Delta V}= \frac{1440\,J }{ 120\,V}= 12 \frac{\cancel{J }}{ \cancel{J}/C}= 12\,C$

Therefore, the amount of charge moved is 12 Coulombs.