Confused about Current Flow & Capacitances

[D_DaYwAlKeR]

I have some doubts regarding Current Flow and Capacitances...

I Read this somewhere..
" an electrochemical cell supplies energy to move a charge from its low energy, low potential terminal to the high energy, high potential terminal. In this sense, the cell supplies the energy to establish an electric potential difference across the two ends of the external circuit. Charge will then flow through the external circuit in the same manner that water will flow from an elevated position to a low position. It is the difference in potential that causes this flow..."


it says that charge (electron) will travel from Low potential to high potential...
then its says that it will move in the same manner that water will flow from an elevated position to a low position..( high potential to low potential...) ..i didnt get this at all..!

 

[Nugatory]

it says that charge (electron) will travel from Low potential to high potential...
then its says that it will move in the same manner that water will flow from an elevated position to a low position..( high potential to low potential...) ..i didnt get this at all..!

It's just a matter of a sign convention, because electrons are said to have negative charge. Life would be a lot easier if a century and a half ago we had decided to call the electron's charge "positive" instead of "negative" so that they would naturally move from areas of high "positive" charge to low "positive" charge - but back then we didn't know which direction the physical charge carriers were moving, and arbitrarily chose a sign convention that turns out to be inconvenient for talking about electrons.

To this day we take power from the positive terminal of a battery, and talk about the wiring diagram as if electrical current is flowing "downhill" from the positive terminal; but what's actually happening physically is that electrons are flowing "uphill" from the negative terminal.

 

[D_DaYwAlKeR]

I got it nw...

Electron loses potential energy as it moves from low potential to high potenital..!...thnxx...@Nugatory!

 

[Jasso]

I believe the beginning they are talking about a chemical battery; it talks about moving the charge from a low energy state to a high energy state.

In a battery, a chemical reaction supplies the energy to separate the charges between the cathode and anode, which causes an electrical potential difference across the terminals and puts the charges into a high potential energy state. When the terminals are connected by a conductor, the stored energy is releases as current. And as Nugatory said, the convention is to label the current as flowing from positive to negative.

 

[sardar]

Current flow and capacitance are important concepts in the study of electricity and electronics. Let me try to explain them in simpler terms.

Current flow refers to the movement of electric charge through a medium, such as a wire or a circuit. It is measured in units of amperes (A) and is represented by the symbol "I". In the context of an electrochemical cell, current flow refers to the movement of electrons from the negative terminal (low energy, low potential) to the positive terminal (high energy, high potential).

Now, let's talk about capacitance. Capacitance is a measure of how much charge a capacitor can store at a given voltage. A capacitor is an electronic component that stores energy in an electric field. It is represented by the symbol "C" and is measured in units of farads (F). In simpler terms, capacitance is the ability of a material or device to hold an electric charge.

Now, going back to the statement you read, it is correct that an electrochemical cell supplies energy to move charge from its low potential terminal to its high potential terminal. This is because the negative terminal has an excess of electrons while the positive terminal has a deficit of electrons. This creates a potential difference, or voltage, between the two terminals. And as we know, opposite charges attract each other, so the electrons will naturally flow from the negative to the positive terminal.

The analogy with water flow is used to explain the concept of potential difference. Just like water flows from a higher to a lower position due to the force of gravity, electrons will flow from a higher to a lower potential due to the force of attraction between opposite charges. So, in both cases, the flow is from high to low.

I hope this helps clarify your doubts about current flow and capacitance. It is important to understand these concepts as they form the basis of many electronic devices and systems. If you have any further questions, please feel free to ask.