Question

show graphically the variation of magnetic field due to a straight conductor of uniform cross section of radius a and carrying steady current as a function of distance r(a>r) from axis of the conductor

Answer 1

We assume that the wire carrying current "i" is a long one and the distance of the point P at which B is measured is small from the wire.

$B=\frac{\mu_0}{2 \pi}\frac{i}{d},\ \ \ \ a\ \textless \ =d\ \textless \ =\infty\\Direction=Radially-outwards.\\\\B=C*\frac{1}{d},\ where C=constant.$

The graph will look like that   of   y = 1/x   or    xy = 1.

Also  for    0<= d <= a, the magnetic field B inside the conductor is 0, as inside a conductor magnetic field is 0.