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I don't understand what does magnetic field energy density stand for? The possible work that the magnetic field can do? So we can calculate the amount of "work" it can do just from the energy density?

Example: A magnetic field is created by a solenoid, there is a energy density of 10J/m3. From that can I derive the magnitude of magnetic force using work = F*d Thus, it would be F = W/d?

gregsan
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Pupil
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2 Answers2

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This is a measure of the energy stored in an inductor. Energy density only makes sense when the field in enclosed by some arbitrary volume--such as the energy density inside the inductor coil (solenoids are inductors too).

$\eta=\frac{B^2}{2\mu_0\mu_r}$

Ref: http://hyperphysics.phy-astr.gsu.edu/hbase/electric/indeng.html#c2

Gala Z.
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Imagine a magnet which produces a magnetic field B. The energy density means that the ratio of the magnetic energy and the volume in a certain space. If we put another magnet in the filed, this magnet will feel a potential due to the field or the energy around it. The amount of potential is related to energy density tightly.

ever_never
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