5. A thermionic diode consists of two flat plate electrodes called the cathode and the anode that are separated by a distance d. Let the potential of the cathode be 0 (zero) and the potential of the anode be V, where Vo > 0. If the potential between the anode and cathode can be described by V(x) = V,(x/ld) (a) find the volume charge density between the anode and the cathode (b) the surface charge density on the cathode ( c) the surface charge density on the anode and (d) the total charge on the diode. Assume the surface areas of both the anode and cathode are A.