Question

The phase difference between.the flux linked with a coil rotating in a uniform magnetic field and induced emf produced in it is

• A. $\pi /2$
• B. $\pi /3$
• C. $-\pi /6$
• D. $\pi$

Answer 1

The correct option is A $\pi /2$

The flux linked with the coil $\varphi =B.A=BA\cos wt$ where $w$ is the angular speed of rotation

Induced emf $E=-\frac{d\varphi }{dt}=-\left(BAw\right)(-\sin wt)=BAw\sin wt$

$⟹$ $E=BAw\cos (wt-\frac{\pi }{2})$

Hence phase difference between flux linked with the coil and induced emf is $\pi /2$.