Question

In a coaxial, straight cable, the central conductor and the outer conductor carry equal currents in opposite directions. The magnetic field is zero.
A. outside the cable
B. outside the cable
C. inside the inner conductor
D. in between the two conductors

Answer 1

Correct Answer - A

At distance `r` from centre `(rgtC)`
Net enclosed current `=0`
Hence `B_(P)=0`