A straight conductor carriers a current alon the `z`-axis Consider the points `A(a,0,0),B(0,-a,0),C(-a,0,0)` and `D(0,a,0)`
(i) All four points have magnetic fields of the same magnitude.
(ii) All four points have magnetic fields of the different direction.
(iii) The magnetic fields at `A` and `C` are in opposite directions
(iv) The magnetic fields at `A` and `B` are mutually perpendicular

Options

A. All four points have magnetic fields of the same magnitude
B. All four points have magnetic fields in different directions
C. The magnetic fields at A and C are in opposite directions
D. The magnetic fields at A and B are mutually perpendicular

Answer

A,B,C,D

Explanation

`B=(mu_(0)I)/(2pi r)` due to a long conductor