Why do inductors store energy in mag. field?

[cdotter]

I understand that moving charges generate a magnetic field, but what makes an inductor energy in a magnetic field? Is it just something that is, or is there a physical reason behind it?

 

[Andrew Mason]

I understand that moving charges generate a magnetic field, but what makes an inductor energy in a magnetic field? Is it just something that is, or is there a physical reason behind it?

In order to build up a current in an inductor, one has to expend energy opposing the induced emf as the current is increasing. As a result of the current being established, the inductor now has a magnetic field. When the current stops, the energy expended in setting up the current is regained. This is because the reduction in current induces an emf that tends to oppose the reduction. The idea that the energy is stored in the magnetic field is just a handy way to conceptualize what occurs.

AM