The magnetic induction due to an infinitely long straight wire carrying a current `i` at a distance `r` from wire is given by

The magnetic induction at any point due to a long straight wire carrying a current is

Write an expression for the magnetic field produced by an infinitely long straight wire carrying a current I, at a short perpendicular distance a from itself.

The direction of magnetic field at a point due to an infinitely long wire carrying current is

Derive an expression for the magnetic field due to an infinitely long straight wire carrying current I.

The field due to a long straight wire carrying a current I is proportional to

The magnetic field due to a long straight wire carrying current varies directly as distance. (Correct the sentence)