(A) : A current I flows along the length of an infinitely long, straight, thin-walled pipe. Then the magnetic field at all points inside the pipe is zero.
(R) : The whole pipe carrying current can be supposed to be made of thin rings. The magnetic field on the axis of the ring is is zero.

Options

A. Both 'A' and 'R' are true and 'R' is the correct explanation of 'A'.
B. Both 'A' and 'R' are true and 'R' is not the correct explanation of 'A'
C. 'A' is true and 'R' is false
D. 'A' is false and 'R' is false

Answer

C