Generally speaking, it refers to the energy associated with magnetism. Strictly speakingShould refer toMagnetic energy。To establish current in coil, resist theSelf induced electromotive forceThe energy associated with work is called self induced magnetic energy.There is mutual inductance between the two coils. The current is established in the two coils respectively. In addition to doing work against the self induced electromotive force of the coil, it will also resist theMutual inductance electromotive forceThe energy associated with the latter is called mutual inductance magnetic energy.
Mi and j are mutual inductance, and the energy of Mij and Mji will not be calculated repeatedly[1]
Related formula
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Another expression of magnetic energy
The expression of magnetic energy does not mean that magnetic energy is related to current.It can be rewritten into another expression form as the following formula through the magnetic field formula
It indicates that the space where the magnetic field exists can be divided into countlessVolume elementThe magnetic energy of each volume element is the data calculated by the above formula
Where B is the magnetic flux density, H ismagnetic field intensityThe integral covers the space where the magnetic field exists.
In the magnetostatic case, current and magnetic field always exist together. Therefore, the effect of considering magnetic energy as being associated with current or stored in magnetic field is identical.But sciencePractical proofMagnetic field is a special form of material, which can exist without current.The changing electric field can also produce magnetic field, and the magnetic field produced by this changing electric field also has energy, and its field energy density is the same as that of magnetostatic field.In general, variableelectromagnetic fieldPropagation in the form of waves,Communication processAccompanied byenergy transfer。
