Question

when and why does a capacitor discharge?
what about the case when AC current is passed

Answer 1

its like asking.. if you take a ball to a certain height.. and you leave it why does it fall back down ? do you see the connection between this and capacitor discharging? :D

Answer 2

ok,, so it discharges whenever it finds a component whose potential difference is lesser than that of itself?

Answer 3

don't think of it taht way

the capacitor will always try to discharge.. just like how the ball will always try to fall
but if you connect a battery of higher emf than the potential difference of the capacitor itself

its like you coming in between and raise the ball even HIGHER.. so, the battery will keep doing work and charging it, until it can't no more.. (when the capacitor voltage equals that of the battery)

Answer 4

ok , then y does a capacitor discharge when AC voltage starts decreasing from the maximum?

Answer 5

so that even the potential across the plates decrease along with the source?

Answer 6

*potential difference

Answer 7

ok.. when u consider a circuit with JUST a capacitor and battery, and imagine there is no resistance AT ALLL, then the capacitor charges and discharges INSTANTLY..

so its like i keep the battery across the cap.
now i put 5V in the battery, instantly cap becomes 5V
i decrease to 3V, instantly cap will discharge and become 3 V

so now imagine if you put an AC along the capacitor, the capacitor voltage will nicely follow the AC right? cause there is instantaneous charging and discharging!..

Answer 8

ok,,,thanks!!