is there any current passing through the capacitor in ac, or just changing polarity of plates?

 

It's pretty much from moving charge onto and off the plates. Here is a link into our Ebook with information - http://www.allaboutcircuits.com/vol_2/chpt_4/2.html.

 

is there any current passing through the capacitor in ac, or just changing polarity of plates?

No current passes through a capacitor in reality except some leakage current. You just change the amount of charge on the plates by supplying or taking electrons from them.

 

No current passes through a capacitor in reality except some leakage current. You just change the amount of charge on the plates by supplying or taking electrons from them.

DC will not flow through a capacitor, but alternating current definitely will.

 

It is called 'displacement current'. I will explain this further If SonyTJ is still with us.

 

studiot is correct, it is displacement current as opposed to conduction current, as the current arises from the displacement of bound charge (electric dipoles) within the dielectric. leakage current would be a result of the free charge that is present within the dielectric.