## College Physics (4th Edition)

$B = 3.3~T$
We can convert the angular speed to units of rad/s: $\omega = 350~rpm \times \frac{1~min}{60~s} \times \frac{2\pi~rad}{1~rev} = 36.65~rad/s$ We can find the strength of the magnetic field: $emf = \omega~NBA$ $B = \frac{emf}{\omega~NA}$ $B = \frac{emf}{\omega~N~\pi~r^2}$ $B = \frac{17.0~V}{(36.65~rad/s)(50)(\pi)(0.030~m)^2}$ $B = 3.3~T$