Equivalent Capacitance of Capacitors in Parallel

CT = C1+C2+...+CN

where CT is the total capacitance, C1, C2,...,CN are the N capacitors in parallel

Equivalent Capacitance of Capacitors in Series

1/CT = 1/C1+1/C2+...+1/CN

where CT is the total capacitance, C1, C2,...,CN are the N capacitors in series

Equivalent Capacitance of Two Series Capacitors

CT = C1C2 / (C1+C2)

CT equals C1 and C2 in series

Charge Storage in an Capacitor

Q = CV

C = Q / V

V = Q / C

Q = charge (coloumb);

C = capacitance (F);

V = voltage (V)

Energy Storage in an Capacitor

E = CV² / 2

C = 2E / V²

V = sqrt(2E / C)

E = Energy (J);

C = capacitance (F);

V = voltage (V)

Constant Charging/

Constant Discharging

V = It / C

I = CV / t

C = It / V

t = CV / I

where C = capacitance (F);

V = voltage (V)

I = current (A)

t = time (s)

Instantaneous Charging/

Instantaneous Discharging

i = C dv/dt

v = 1/C ∫ idt

where C = capacitance (F);

v = voltage (V)

i = current (A)

dv = change in voltage (V)

dt = time interval (s)

Capacitive Reactance

Xc = 1 / (2πfC)

where Xc = capacitive reactance;

C = capacitance;

f = frequency

Parallel Plate

Capacitance

C = [8.855(N-1)kA] / d

where C = capacitance (pF);

N = number of plates

k = relative dielectric constant

A = plate area, sq. m

d = dielectric thickness, m