Faraday's law of magnetism

Mathematically, it is expressed as:

$$\mathcal{E} = -N \frac{d\Phi_B}{dt}$$

Where:

• $\mathcal{E}$ is the induced electromotive force (EMF) in volts (V).
• $N$ is the number of turns in the coil.
• $\frac{d\Phi_B}{dt}$ is the rate of change of magnetic flux ($\Phi_B$) with respect to time (t). Magnetic flux is measured in Webers (Wb).
• The negative sign indicates the direction of the induced EMF, which is given by Lenz's Law: the induced current will flow in a direction that opposes the change in magnetic flux that produced it.

This law is fundamental to the operation of generators, transformers, and many other electrical devices.