capacitance calculation

Discussion in 'General Electronics Chat' started by samjesse, Aug 14, 2009.

1. samjesse Thread Starter Active Member

Sep 14, 2008
202
0
the formula to calculate the capacitance is

C = (ε A)/d

where ε is dielectric absolute permittivity
A is the overlap area in what units?
d is the distance between the plates in meters

what is the formula to use the relative permittivity instead?

Thank you

2. studiot AAC Fanatic!

Nov 9, 2007
5,005
513
area is measured in square metres in the MKS (ISO) system.

3. rspuzio Active Member

Jan 19, 2009
77
0
> A is the overlap area in what units?
> d is the distance between the plates in meters

Since you will measure d in meters, to be consistent, you
need to measure A in square meters.

> what is the formula to use the relative permittivity instead?

Write $\epsilon = \epsilon_{rel} \epsilon_0$, where
$\epsilon_{rel}$ is the relative permittivity (a.k.a.
dielectric constant) and $\epsilon_0$ is the vacuum
permittivity (which equals $8.85 \times 10^{-12} \, F/m$).

Last edited: Aug 14, 2009