1. A coaxial cable consists of an inner conductor of radius a and an outer conductor of radius b. The current in the inner conductor is uniformly distributed while the outer conductor has negligible thickness and provides a return path to the current. Calculate the self inductance of the cable.

2. Find the mutual inductance of two coplanar squares with a common centre assuming that the square located inside is much smaller in dimension *b* than the bigger square which has a side *a*.

3. The current through a straight wire varies with time as where the current is in Amperes and time in seconds. If the radius of cross section of the wire is 50 (mm)^{2} and the resistivity , estimate the displacement current density and compare it with the conduction current density.

4. A capacitor plate of area 0.3 m^{2} is being charged at a uniform rate so that the electric field inside the plate varies with time as V/m-s. Calculate the displacement current and estimate the magnetic field strength at a distance 5 cm from the centre of the capacitor plate along a line parallel to both the plates.