The Energy in an Inductor calculator computes the energy from the inductance and current.
INSTRUCTIONS: Choose units and enter the following:
Inductor's Energy (EL): The energy is returned in Joules. However, this can be automatically converted to compatible units via the pull-down menu.
The Inductor's Energy is found using the following formula:
`E_L = L/2I^2`
where:
How much energy does an inductor store? The energy density is proportional to the square of the magnetic field strength, which is in turn proportional to the current flowing through the coiled wire, so the energy stored in the inductor must be proportional to `I^2`. We write `L"/"2` for the constant of proportionality, giving
As in the definition of capacitance, we have a factor of 1/2, which is purely a matter of definition. The quantity L is called the inductance of the inductor, and we see that its units must be joules per ampere squared. This clumsy combination of units is more commonly abbreviated as the henry, 1 henry = 1 `J"/"A^2`. Rather than memorizing this definition, it makes more sense to derive it when needed from the definition of inductance. Many people know inductors simply as “coils,” or “chokes,” and will not understand you if you refer to an “inductor,” but they will still refer to `L` as the “inductance,” not the “coilance” or “chokeance!”
25.1 Capacitance and inductance by Benjamin Crowell, Light and Matter licensed under the Creative Commons Attribution-ShareAlike license.