# Energy Density (electric field)

## Description

Lenz’s law /ˈlɛnts/ is a common way of understanding how electromagnetic circuits obey Newton’s third law and the conservation of energy. Lenz’s law is named after German scientist Heinrich Lenz in 1834, and it says:

If an induced current flows, its direction is always such that it will oppose the change which produced it.

The electric field stores energy. The energy density of the electric field is given by the formula shown here.

This energy density can be used to calculate the energy stored in a capacitor.

Related formulas## Variables

U | energy density of the electric field (joule/m^{3}) |

ϵ_{0} | electric constant |

E | induced voltage (N*coulomb^{-1}) |