**infinite conducting planes at z=0 and z=d carry currents in opposite directions with surface current density in the same directions . Calculate the magnetic field everywhere in space.**

1. Two** **infinite conducting planes at z=0 and z=d carry currents in opposite directions with surface current density in the same directions . Calculate the magnetic field everywhere in space.

2. Two infinite conducting sheets lying in x-z and y-z planes intersect at right angles along the z axis. On each plane a surface current . flows. Find the magnetic field in each of the four quadrants into which the space is divided by the planes.

3. Consider the loop formed by two semicircular wires of radii and and two short straight sections, as shown. A current I flows through the wire. Find the field at the common centre of the semicircles .

4.The current density along a long cylindrical wire of radius *a* is given by , where r is the distance from the axis of the cylinder. Use Ampere’s law to find the magnetic field both inside and outside the cylinder.