Write down the eqution for the magnetic field induction (B) at a distance (S) from a long straight conductor carrying current I.

Sketch a curve to show the variation of magnetic flux density (B) with distance from a long straight conductor carrying current I.

The magnetic field induction at a long distance from a short bar magnet along axial and equatorial positions are in the ratio

Derive an expression for the magnetic induction at a nearby point of a straight and long current-carrying conductor. Discuss the nature of the magnetic lines of induction.

The magnetic field induction at a point due to a current element is given by