Question

A coaxial cable consists of a thin inner conductor fixed along the axis of a hollow outer conductor. The two conductor carry equal currents in opposite directions. Let `B_1 and B_2` be the magnetic fields in the region between the conductors and outside the conductor, respectively. Then,
A. `B_(1)ne0,B_(2)ne0`
B. `B_(1)=B_(2)=0`
C. `B_(1)ne,B_(2)=0`
D. `B_(1)=0,B_(2)ne0`

Answer 1

Correct Answer - C

Let `r:` distance from centre `O`
For `a lt r lt b, B_(1)=(mu_(0)I)/(2pir)`
`r gt c, B_(2)=0`