# A charge of 5 C is passing through points A and B on a circuit. If the charge's electric potential changes from 28 J to 15 J, what is the voltage between points A and B?

Apr 12, 2018

#### Answer:

Point A is at a voltage $2.6$ $V$ higher than point B. We would express this as $- 2.6$ $V$ from A to B.

#### Explanation:

One volt is defined as one joule per coulomb, which we can write as $V = \frac{U}{C}$ where $V$ is the voltage difference, $U$ is the electric potential in joule and $Q$ is the charge in coulomb.

In this case we're interested in the potential difference, so

$V = \frac{\Delta U}{Q} = \frac{15 - 28}{5} = \frac{- 13}{5} = - 2.6$ $V$

That is, point A is at a voltage $2.6$ $V$ higher than point B.