# I still don't get Voltage and batteries watch

1. Hey, i'm in my first year studying EEE and i've realised i don't really understand what voltage is or how a battery works. Anytime i look online or try to find the answers i'm looking for i tend to get pointless answers, for example "Voltage is the current x the resistance", or just answers i don't really understand. I'm looking for answers to my questions that are fairly simple explanations and perhaps describe voltage and batteries at the atomic level:
Am i correct in saying that voltage is the difference in potential energy between 2 points? If so, what establishes that potential energy and what changes that potential energy into (kinetic?), moving the electrons around the circuit? What force is it that pushes the electrons, how does it work and where does it come from, i'm assuming the battery? Am i correct in saying that batteries hold chemical energy, and when it's connected to a circuit, bonds begin to break which somehow turns the chemical energy into heat energy?

I should probably know all this and i feel a bit daft not knowing what is probably one of the most common and simple things to know about circuits, however, any help is appreciated

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2. I ment to say changing chemical energy into kinetic energy :P

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3. It's basically electrical potential energy. Electrons repel one another due to the Coulomb force so, if you have a high electron density at one end of the battery, they will try to push their way out along the path of least resistance. In a circuit that path is normally along the wire.

As for how batteries work, it involves the oxidization and reduction of two different ionic solutions separated by a salt bridge, and I don't fully understand it because I never did chemistry beyond GCSE. But the end result is that they manage to maintain a constant electric potential difference, which forces electrons to keep flowing from one solution to the other via a circuit.
4. (Original post by Arbolus)
It's basically electrical potential energy. Electrons repel one another due to the Coulomb force so, if you have a high electron density at one end of the battery, they will try to push their way out along the path of least resistance. In a circuit that path is normally along the wire.

As for how batteries work, it involves the oxidization and reduction of two different ionic solutions separated by a salt bridge, and I don't fully understand it because I never did chemistry beyond GCSE. But the end result is that they manage to maintain a constant electric potential difference, which forces electrons to keep flowing from one solution to the other via a circuit.
I found a page earlier that was able to explain a lot to me, it says "This force is called electromotive force, or EMF. Sometimes it is convenient to think of EMF as electrical pressure. In other words, it is the force that makes electrons move in a certain direction within a conductor. Batteries are constructed so there are too many electrons in one material and not enough in another material. The electrons want to balance the electrostatic charge by moving from the material with the excess electrons to the material with the shortage of electrons. The battery will work until there is a balance of electrons at both ends of the battery. Think of electricity flowing in a wire in the same way as the water flowing in the hose. The voltage causing the electrical current to flow in the wire can be considered the water pressure at the faucet, which causes the water to flow. If we were to increase the pressure at the hydrant, more water would flow in the hose. Similarly, if we increase electrical pressure or voltage, more electrons would flow in the wire. " My only question now is:
Is this electrical pressure what is meant by electrical potential
? If so, how would you increase this "pressure"? By creating more of a misbalance or electrons within the battery?
5. (Original post by zRydo)
I found a page earlier that was able to explain a lot to me, it says "This force is called electromotive force, or EMF. Sometimes it is convenient to think of EMF as electrical pressure. In other words, it is the force that makes electrons move in a certain direction within a conductor. Batteries are constructed so there are too many electrons in one material and not enough in another material. The electrons want to balance the electrostatic charge by moving from the material with the excess electrons to the material with the shortage of electrons. The battery will work until there is a balance of electrons at both ends of the battery. Think of electricity flowing in a wire in the same way as the water flowing in the hose. The voltage causing the electrical current to flow in the wire can be considered the water pressure at the faucet, which causes the water to flow. If we were to increase the pressure at the hydrant, more water would flow in the hose. Similarly, if we increase electrical pressure or voltage, more electrons would flow in the wire. " My only question now is:
Is this electrical pressure what is meant by electrical potential
? If so, how would you increase this "pressure"? By creating more of a misbalance or electrons within the battery?
Yes, yes it is. EMF and potential difference are just different ways of thinking about the same thing, which is the energy imparted to the electrons. Be careful not to confuse EMF with an actual force or pressure.

In the water pipe analogy, there are two ways of increasing the water pressure. You could attach a pump at one end, or you could raise one end above the other and create a gravitational potential difference. Similarly in a circuit there are two ways of increasing the EMF/electric pressure - you could do something involving magnetic induction, or you could add a battery and create an electric potential difference.
6. (Original post by Arbolus)
Yes, yes it is. EMF and potential difference are just different ways of thinking about the same thing, which is the energy imparted to the electrons. Be careful not to confuse EMF with an actual force or pressure.

In the water pipe analogy, there are two ways of increasing the water pressure. You could attach a pump at one end, or you could raise one end above the other and create a gravitational potential difference. Similarly in a circuit there are two ways of increasing the EMF/electric pressure - you could do something involving magnetic induction, or you could add a battery and create an electric potential difference.
But how is the energy imparted to the electrons? Is voltage the difference in the magnitude of charge between the electrons and ions inside the battery or is it the difference in the number of ions and electrons in the battery? What would be the difference, atomically, inside the battery, between a 3V battery and a 6V battery for example?

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7. Can anyone else help?

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8. Bump

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