# Question #4d52c

##### 1 Answer

Feb 13, 2017

#### Answer:

As a consequence of the law of conservation of energy, the total change in electric potential around any closed loop in a circuit must be zero.

#### Explanation:

Since changes in voltage are equivalent to changes in potential energy of the moving charges (but are measured on a joules per coulomb basis) voltage is subject to the same behaviour as potential energy.

When a body in a gravitational field completes a closed path, it's overall change in potential energy is zero.

Similarly, when a charge completes a loop in a closed path, the total change in potential (as well as its total change in potential energy) must be zero.

This is one of Kirchoff's laws, generally called the loop rule.