A simple capacitor is a device formed by two insulated conductors adjacent t0 each other. If equal and opposite charges are placed on the conductors_ there will be certain difference of potential between them: The ratio of the magnitude of the charge on one conductor t0 the magnitude of the potential difference is called the capacitance (in SI units it is measured in farads). Using Gauss' Iaw, calculate the capacitance of
(a) two large flat conducting sheets of area A, separated by a small distance d;
(b) two concentric conducting spheres with radii a, b (b > a);
(c) two concentric conducting cylinders of length L, large compared t0 their radii a,b (b > a).
