A coil of turns and area starts from rest at and rotates in a uniform magnetic field…

PHYSICS · Subjective · A Level · Physics · Fields and their consequences · Fields and their consequences

Problem

A coil of

N

turns and area

A

starts from rest at

t = 0

and rotates in a uniform magnetic field

B

with an angular velocity that varies with time as

\omega = \omega_0 + \alpha t

, where

\omega_0

and

\alpha

are constants. Derive an expression for the induced emf

\epsilon(t)

in the coil as a function of time.