I’ve heard the definitions of it being “energy transferred per charge”, “potential difference”, and “the difference between the electrons in the positive and negative terminals of a battery” but I still don’t really understand some of these definitions, and can’t really wrap my head around what exactly is it.
I also don’t really get how it is the thing that can “power up” a circuit (I might have misunderstood this part” and how the definitions above can be the same thing
In: Physics
What level are you trying to understand this at and what concepts are you trying to harmonize?
If you’re asking on a metaphysical, deep level what *is* voltage, then you’re asking for something way above ELI5 and possibly even in the realm of philosophy rather than science.
If you’re asking for a practical explanation such as connecting the ideas of electricity and voltage, then electricity is basically the presence of a voltage along a path. This basic conceptualization is generally explained via a comparison to water in pipes, where water molecules are electrons or “charges”, the pipes are the electrical circuit, amps/amperage is the amount of water flow, voltage is water pressure, resistance is resistance to the flow of water that has to be overcome for water to move through the system.
Now, looking at your examples:
If charges are water molecules and voltage is “energy transferred per charge” then it would be like the pressure of a water hose shooting out water. The water is the same but the speed of each molecule shot out changes. Each molecule’s energy changes as the water pressure changes. Same with electricity and voltage. The higher the voltage the more energy in each charge, so it can overcome greater resistance to its movement. For example, high voltage can cause electricity to “jump” or arc over air to another place, just like high water pressure can shoot a stream of water across air where otherwise it would just hit the ground.
“Potential difference”. To conceptualize this, think of a water tower. The higher the tower, the more potential energy the water in it has, for it to be able to distribute water over a larger area, or with more pressure to the same area. Same with electricity. Voltage would represent the potential for charges to be forced either across a larger circuit with the same resistance or a smaller circuit with higher energy per charge. In this sense, voltage differential between two locations (terminals) can be seen as the ability for charges to do work as they are pushed from one terminal to the other.
“Difference between electrons in the positive and negative terminals of a battery” this is the same as potential difference but worded differently. Take the idea of an old fashioned scale, where to balance both sides you have to have the same weight. Electricity is the same, in that if both sides of a circuit (terminals) have the same charge amount (weight), then nothing will happen. There is no difference, or the differential is 0. Voltage then can be conceptualize as how high one side of the scale is compared to the other side. More of a difference, more voltage. For a water analogy, it’s like having a water tower with lots of water trying to go through pipes to a reservoir beneath it. If the reservoir is empty, then the difference in water in each place is very large, i.e. voltage would be large, but as water goes from the tower to the reservoir the difference becomes less until it balances out. The voltage would decrease as charges balance out on either end (terminal) of the circuit until it gets to zero.
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