NTA Abhyas JEE Main2020PhysicsMagnetic Effects of CurrentPractice
An infinitely long hollow conducting cylinder with inner radius R 2 and outer radius R carries a uniform current density along its length. The magnitude of the magnetic field, B → as a function of the radial distance r from the axis, is best represented by:
Correct answer
3
Step-by-step solution
r < R 2 , B = 0 r > R , B = μ 0 I 2 π r R 2 < r < R , B = μ 0 I 2 π r r 2 - R 2 2 R 2 - R 2 2