Induced Electromotive Force

When the magnetic flux ($\Phi_B$) through the area of a wire loop changes, there will be an induced electromotive force in the loop to oppose the change.

Faraday’s Law

\[\mathcal{E} = -\frac{d\Phi_B}{dt}\]

Method for Solving

There are a few common ways the magnetic flux through an area can be changing:

• The magnetic field strength changes
• The area increases or decreases
• The area rotates
• The area moves between areas of different field strength