a simple question about capacitor

Thread Starter

fankoushat

Joined Mar 8, 2010
17
Hi,

If I told you that 1 coloumb has been stored in a capacitor, does this mean, + 1 q on one plate and -1 q on the other? or +0.5 q on one plate and -0.5 on the other?


Thanks :)
 

kkazem

Joined Jul 23, 2009
160
Hi,
This is a fairly simple problem. The answer is that there is indeed +1q on one plate and -1q on the other plate. If the capacitor is a 1 farad cap, then there would be a potential difference (or more simply, a voltage) of 1 volt across the capacitor's terminals by the formula: , C=q/v, where: C = Capacitance, q=charge, and v=volts. The same 1 coulomb charge would exist on both the positive plate and on the negative plate. This is so by the definition of charge, which is that 1 coulomb = the amount of charge thru a conductor with a current of 1 ampere in 1 second. When charging a cap, the same current goes into both plates, thus, an equal but opposite charge exists on the two plates, but their value will be equal in the example I mentioned above.

Regards,
Kamran Kazem
 
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