Q. The magnetic field between the plate of a capacitor where $r > R$ is given by (where $r$ is the distance from the axis of plates and $R$ is the radius of each plate of capacitor)
A) $\frac{\mu_{0}i_{D}r}{2\pi R^{2}}$
B) $\frac{\mu_{0}i_{D}}{2\pi R}$
C) $\frac{\mu_{0}i_{D}}{2\pi r}$
D) Zero
Explanation
(c) Using Ampere circuit law,
$\oint\overrightarrow{\mathbf{B}}\mathbf{\bullet}\overrightarrow{\mathbf{dl}} = \mu_{0}i_{D}$
or $B2\pi r = \mu i_{D}$
or $B = \mu_{0}i_{D}/2\pi r$
Reviewed by Dr. Abubacker
Physics Educator & NEET/JEE Specialist
Ph.D. in Physics with 19+ years of teaching experience.