Consider a coaxial cable consisting of an inner wire of radius

PHYSICS · Single correct · CBSE · Physics · Moving Charges and Magnetism · Moving Charges and Magnetism

Problem

a

, surrounded by an outer shell of inner and outer radii

b

and

c

, respectively. The inner wire carries a current

I

and the outer shell carries an equal and opposite current. The magnetic field at a distance

x

from the axis, where

b < x < c

, is (a)

\frac{\mu_0 I(c^2-b^2)}{2\pi x(c^2-a^2)}

(b)

\frac{\mu_0 I(c^2-x^2)}{2\pi x(c^2-a^2)}

(c)

\frac{\mu_0 I(c^2-x^2)}{2\pi x(c^2-b^2)}

(d) zero