# capacitance

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#1
1)Does current flow in a circuit having a capacitor?
2)Is the resistance across the capacitor infinite because the potential difference across it is equal to the emf of the supply?
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4 months ago
#2
(Original post by Vand3rwaal)
1)Does current flow in a circuit having a capacitor?
2)Is the resistance across the capacitor infinite because the potential difference across it is equal to the emf of the supply?
Yeah current flows during the time the capacitor is charging or discharging. For a dc circuit with low series resistance that might be a very short time.
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#3
Why is that? May i ask?
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4 months ago
#4
(Original post by Vand3rwaal)
1)Does current flow in a circuit having a capacitor?
2)Is the resistance across the capacitor infinite because the potential difference across it is equal to the emf of the supply?

Consider a pair of uncharged parallel plates connected to a battery of certain emf Ve. Each plate is connected to one terminal of a battery, which acts as a source of potential difference. The battery establishes an electric field in the connecting wires when the connections are made. If we focus on the plate connected to the negative terminal of the battery and see what is going on. The electric field in the wire applies a force on electrons in the wire immediately outside this plate; this force causes the electrons to move onto the plate. The movement continues until the plate, the wire, and the terminal are all at the same electric potential.
Once this equilibrium situation is attained, a potential difference no longer exists between the terminal and the plate; as a result, no electric field is present in the wire and the electrons stop moving. The plate now carries a negative charge. A similar process occurs at the other plate, where electrons move from the plate to the wire, leaving the plate positively charged.
In conclusion, the flow of electrons (or current) occurs only in s very short time interval.

As for question 2, I would say it depends on how you see the question. I believe the answer from physics stackexhange would offer some interesting insights to the questions.
https://physics.stackexchange.com/qu...-of-capacitors
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