Q. In an AC generator, a coil with $N$ turns, all of the same area $A$ and total resistance $R$, rotates with frequency $\omega$ in a magnetic field $B$. The maximum value of emf generated in the coil is
A) $NABR\omega$
B) $NAB$
C) $NABR$
D) $NAB\omega$
Explanation
(d) The emf generated would be maximum when flux (cutting) would be maximum $ie,$ angle between area vector of coil and magnetic field is $0{^\circ}$. The emf generated is given by [as a function of time]
$\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ e = NBA\omega\cos{\omega t}$
$\Rightarrow \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ e_{\max} = NAB\omega$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.