Find the electric field between two metal plates 3 mm- apart connected to 12 V battery.

A parallel plate air capacitor is made using two plates 0.2 m square , spaced 1 cm apart . It is connected to a 50V battery. (a) what is the capacitance ? (b) what is the charge one each plane ? (c) what is energy stored in the capacitor ? (d) what is the electric field between the plates ? (e) If the battery is disconnected and then the plates are pulled apart to a separation of 2 cm , what are the answer to the above parts ?

A parallel -plate capacitor having plate area 25.0 cm^2 and a separation 2.00 mm between the plates .the capacitor is connected to a battery of 12.0 V.(a)find the charge on the capacitor .(b) the plate separation is decreased to 1.00 mm. Find the extra charge given by the battery to the positive plate.