Current flowing in a Capacitor 

The current flowing in a capacitor is proportional to the product of the capacitance, C, and the rate of change of applied voltage.

i = C × (rate of change of voltage[dV/dt]).

How to Compute Charge or Quantity of Electricity.

Q = CV

where Q is the charge (in coulombs), C is the capacitance (in farads), and V is the potential difference (in volts). 

Energy Storage in a Capacitor

W = ½ C V*V

where W is the energy (in Joules), C is the capacitance (in Farads), and V is the potential difference (in Volts).

Capacitance of a conventional parallel plate

C=E0*Er*A/D

A is the surface area , C is the capacitance (in farads), ) E0 is the permittivity of free space, Er is the relative permittivity of the dielectric medium between the plates), and D is the separation between the plates (in meters).

Capacitors connected in parallel

C=C1+C2+C3+-----

Capacitors connected in series

1/C=(1/C1)+(1/C2)-----

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