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)
Answer & explanation
Correct answer: option 3
Using Ampere circuit law,
$\oint \vec{B}.\vec{dl} = \mu_0i_D$
$ or\, B.2\pi r = \mu_0 i_D$
$ or \, B = \frac{\mu_0 i_D }{2\pi r}$