A uniform but time varying magnetic field $B\ (t)$ exists in a circular region of radius a and is directed into the plane of the paper as shown in figure. The magnitude of induced electric filed at point P at a distance r from the centre of the circular region [image:6_image51.emf]

Question

Dr. Abubacker · Accepted Answer

(b) For $r\  \geq a,\ \oint\overrightarrow{E}\ d\ \overrightarrow{I}$
$= \ \left| \frac{d\phi}{dt} ight| = A\ \left| \frac{dB}{dt} ight|$
$E(2\pi r) = \pi a^{2}\ \left| \frac{dB}{dt} ight|\ \ \frac{a}{2}$
$E = \frac{a^{2}}{2r}\ \left| \frac{dB}{dt} ight|$
[image:6_image70.emf]
$	herefore\ \ $Induced electric filed, $E\  \propto \frac{1}{r}$

Q. A uniform but time varying magnetic field $B\ (t)$ exists in a circular region of radius a and is directed into the plane of the paper as shown in figure. The magnitude of induced electric filed at point P at a distance r from the centre of the circular region

Explanation

Reviewed by Dr. Abubacker

Want more practice?