A capacitor is made from two parallel plates of area A, which are separated by a distance d. The region between the plates is filled by a dielectric of dielectric constant x. The capacitor is first charged with positive charge Q, and then is disconnected, so it remains isolated throughout the problem. (a) What is the capacitance? (b) What is the magnitude of the electric field between the plates? (c) If the distance between the plates is slowly increased from d to 2d by applying an external force what would be the final potential difference between the plates? (d) How much work would be done by the external force during this process? (e) ( What is the magnitude of the force needed to get the top plate moving when the separation is d? d 2d