Skip to main content

Illustration Time changing magnetic field generates a rotating electric field and vice versa

Time changing magnetic field generates a rotating electric field and vice versa
Get illustration

Share — copy and redistribute the material in any medium or format

Adapt — remix, transform, and build upon the material for any purpose, even commercially.

Sharing and adapting of the illustration is allowed with indication of the link to the illustration.

Time variation of the magnetic field \(\boldsymbol{B}\) or the time variation of the surface \(A\) penetrated by magnetic field \(\boldsymbol{B}\) generates an electric field \(\boldsymbol{E}\) along the edge of the surface \(A\), which can lead to an electric current. This experimental finding is called the law of induction and is mathematically summarized in the fourth Maxwell equation (if \(A\) is kept constant):\[ \nabla \times \boldsymbol{E} ~=~ - \frac{\partial \boldsymbol{B}}{\partial t} \]