How To determine the Capacitance at particular point??????

How we determine the value of the capacitor for particulat point????
is that the capacitor is used to stabilze the voltages o wat???
...... i still not understand about this..........!!!!!! hope some one can explain to me.~~~!! thanks!!! alot...............learning is a FUn.....!!! :shock: :shock: :shock:

I am a relative amateur but I'd offer that the value is determined by what you want the capacitor to do. Some of those things are:

A. Isolate AC and DC- AC will pass but DC won't.
B. Be part of timing or frequency - in an RC or LC arrangement.
C. As part of a filter.
D. To provide a reactance that is proportional to frequency.

So, you need to define the role the capacitor plays, at the very least, before even attempting to determine the value.

Not much but it's a start.

caps are used in rectifing circuits (converting AC to DC) to sabilize the voltage.
They are also used in high power AC circuits that are usually controlling motors (like what industries use) as a power factor corrector. it makes power system more efficient. (I just learned about this in school, so I felt obligated to share 8) )