A + + kdx B The p.d between the metal plates is 40V a) Which plate is cat the higher potential? 5) How much work must be done to carry +3.0c of charge from B to A! How do we know that the electric field is in the direction, indicated? d) (f the plate separation is 5.0mm, what is the magnitude of E? e) Calculate the energy density of the capacitor. charge of +50e.