Acapacitor is not the most efficient device for storing energy. batteries can store more energy in much less space. for example, a typical 12 v automobile battery stores on the order of 1.00 x 10^6 j. (a) find the capacitance necessary to store 1.00 x 10^6 j with a potential difference of 1.00 x 10^4 v across the capacitor's terminals.
(b) suppose that such a capacitor was made in the form of a parallel-plate capacitor with a vacuum between the plates and an electric field no greater than 9.00 x 10^6 v/m. what is the minimum area of the plates?

To understand the behavior of the electric field at the surface of a conductor, and its relationship to surface charge on the conductor. a conductor is placed in an external electrostatic field. the external field is uniform before the conductor is placed within it. the conductor is completely isolated from any source of current or charge. part a: which of the following describes the electric field inside this conductor? it is in the same direction as the original external field.it is in the opposite direction from that of the original external field.it has a direction determined entirely by the charge on its surface.it is always zero. part b: the charge density inside the conductor is: 0non-zero; but uniformnon-zero; non-uniforminfinite part c: assume that at some point just outside the surface of the conductor, the electric field has magnitude e and is directed toward the surface of the conductor. what is the charge density η on the surface of the conductor at that point? express your answer in terms of e and ϵ0