Question

An infinitely long hollow conducting cylinder with inner radius `(r )/(2)` and outer radius `R` carries a uniform current ra density along its length . The magnitude of the magnetic field , ` | vec(B)|` as a function of the radial distance `r` from the axis is best represented by
A.
B.
C.
D.

Answer 1

Correct Answer - `D`
`B xx 2 pix = mu_(0)J(pi(x^(2)-(R^(2))/(4)))`
`B =(mu_(0)J)/(2pi) (x-(R^(2))/(4x))`