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Flow of air?

I’m working on a science project now and I have a doubt,Consider two places(A and B) with a vast temperature difference connected by a insulated pipe,would air flow through the pipe from A to B?lets say A is up in the mountains and B is in the plains,air flows from a cold place to a hot place,doesn’t it?If it does flow, I would like to know how to calculate it’s pressure.If it doesn’t flow,I would like to know the reason for that as well.

The mechanism of operation in a capacitor

The DC doesnt flow through capacitor. I thought it was because the electrons jus get saturated on one side and are lost on other side, such that it can’t take or give up anymore or plausibly due to voltage developed across it whereas in AC as directions keep changing, saturation doesnt occur. But it if it were so then AC would flow through two plates seperated by large distances or switches which can be considered capacitors.So please guide me as to what’s actually happening during current flow through capacitor and how it happens? (The question was posted by Thushar Misra)

Answer:

Your logic is almost correct. A capacitor is a passive electronic component consisting of a pair of conductors separated by a dielectric (insulator). When there is a potential difference (voltage) across the conductors, a static electric field develops across the dielectric, causing positive charge to collect on one plate and negative charge on the other plate. Energy is stored in the electrostatic field.

A current is not “flowing” through a capacitor, the “current” that exists between the plates of a capacitor is called “Displacement current” which is actually caused by the time varying electric flux. This causes the circuit to be continuous though there is no electrical contact or flow of charges between the plates of the capacitor.

When a capacitor is connected to DC, there exists a change in electric flux when the switch is just turned on but soon it reaches steady state and there is no “current”. A capacitor can “conduct” only when there is a “change” in electric flux, which is continuously taking place in an AC.

 

How can the electric current in a circuit be kept continuous?

Susmita asked:

  1. What is Current?
  2. How can electric current in a circuit be kept continuous?

 

Ans:

The word current means flow.

Electric Current refers to charges in motion. The most common way of producing current is by applying a potential difference across the terminals of a conductor. Then the free electrons in the conductor drifts towards the positive terminal.

The current in the circuit can be kept continuous by providing a constant potential difference between two points of the circuit. This is usually done by connecting the ends of the circuit to the terminals of an electrochemical cell (which converts chemical energy to electrical energy) or a dynamo (which converts mechanical energy to electrical energy)

Please refer the following links for more information

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