# A charge of 4 C is passing through points A and B on a circuit. If the charge's electric potential changes from 19 J to 7 J, what is the voltage between points A and B?

Jan 21, 2016

$3 V$

#### Explanation:

If you move 1C of charge through a potential difference of 1V then 1J of work is done.

The amount of work done here is 19 - 7 = 12J

So 4C would require a p.d of 3V to do 4 x 3 = 12J of work

Or using dimensions:

$V = \frac{J}{C} = \frac{12}{4} = 3$

The question should read potential energy, not potential which is in volts not Joules.