I would like to know how potential difference is created between two points?Is potential difference created by adding more electrons at one side?If that's the case how to add more electrons at one side?
I'm really looking to know what really constitutes potential difference?
What is potential difference? It's pretty simple, actually.
In this way, electrons will always try to move towards the lower potential. In other words: if there is a potential difference between two points then electrons will try to move because they experience an electric force towards the lower potential.
How can such a potential difference be established? That's also pretty simple, actually.
To create and sustain a potential difference you need something to move charges "the wrong way". That is, towards the point of higher potential. You just need a force larger than the repelling force.
* The exact inner workings of separation and recombination between electrons and ions across the electrolyte within the battery is a topic in itself in the discipline of electrochemistry. But for the electric considerations we can often black box the battery and purely consider its effect without worrying about how it produces that effect. The battery is in this way just a voltage source.
In a circuit, an electric field is created. This electric field forces electrons to move. As current must remain constant (since no charge build up is observed), the electric field must be strongest in the materials that are the least conductive (or most resistive).
As this electric field moves the electrons, they gain kinetic energy. In order to conserve energy, we must therefore say that the potential energy of these electrons has been converted to kinetic energy. Hence, the potential energy of the electron falls. A potential difference in a circuit merely means that work is done on electrons by an electric field as they pass through the circuit and their potential energy changes. Further, we can conclude that since the electric field is strongest in regions with high resistance, the potential difference must be greatest across these regions as well.
This might be a bit confusing since it implies that potential falls in the direction that electrons flow. Since we choose to deal with the flow of conventional current rather than electron flow, potential falls in the opposite direction of current flow.
I will try to explain with some examples. There is never a potential difference when there is equilibrium.
You can think of it as a height difference. Think of positive potential as a high point and the negative one as a low point or ground. So there is a height difference. A thing at the high point is bound to come down.
Similarly, whenever there is charge imbalance, a potential difference is created. I tried to explain as well as I could but the question of exactly how it is created is kind of an abstract thing. It's like asking how the height difference is created between the two points.
Hope it helps.
