(a) The capacitance of the capacitor is:
and the voltage applied across its plates is
The relationship between the charge Q on each plate of the capacitor, the capacitance and the voltage is:
and re-arranging it we find the charge stored in the capacitor:
(b) The electrical potential energy stored in a capacitor is given by
where C is the capacitance and V is the voltage. The new voltage is
so the energy stored in the capacitor is
and the voltage applied across its plates is
The relationship between the charge Q on each plate of the capacitor, the capacitance and the voltage is:
and re-arranging it we find the charge stored in the capacitor:
(b) The electrical potential energy stored in a capacitor is given by
where C is the capacitance and V is the voltage. The new voltage is
so the energy stored in the capacitor is