A cylindrical capacitor of length L is composed of an inner cylindrical conductor of radius a and a concentric outer conducting cylindrical shell of radius b. A cylindrical shell of dielec- tric material of length L and which just fits in between the conductors (inner radius N a and outer radius N b) is inserted so that half is inside of the capacitor (i.e. L / 2 of the length of the capacitor is now filled with dielectric). (a) What is the capacitance of this arrangement (you may ignore fringing fields at the ends)? (b) The two conductors are held at a constant potential difference, V, using a battery. What is the force on the dielectric (magnitude and direction)? (c) Explain the physical origin of this force