## Summary

- An electric generator rotates a coil in a magnetic field, inducing an emfgiven as a function of time by
\(\text{emf}=\text{NAB}\omega \phantom{\rule{0.25em}{0ex}}\text{sin}\phantom{\rule{0.25em}{0ex}}\mathrm{\omega t}\text{,}\)

where \(A\) is the area of an \(N\)-turn coil rotated at a constant angular velocity \(\omega \) in a uniform magnetic field \(B\).

- The peak emf \({\text{emf}}_{0}\) of a generator is
\({\text{emf}}_{0}=\text{NAB}\omega \text{.}\)

## Glossary

### electric generator

a device for converting mechanical work into electric energy; it induces an emf by rotating a coil in a magnetic field

### emf induced in a generator coil

\(\text{emf}=\text{NAB}\omega \phantom{\rule{0.25em}{0ex}}\text{sin}\phantom{\rule{0.25em}{0ex}}\mathrm{\omega t}\), where \(A\) is the area of an \(N\)-turn coil rotated at a constant angular velocity \(\omega \) in a uniform magnetic field \(B\), over a period of time \(t\)

### peak emf

\({\text{emf}}_{0}=\text{NAB}\omega \)