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FS98
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As I understand it, electrical potential is the potential energy of a unit charge in some point in space. How does this idea relate to the idea of voltage in a circuit? The term electric potential seems to be used for both.
Potential is Potential.FS98 said:The term electric potential seems to be used for both.
Isn’t electrical potential already relative? I thought we just generally use infinity as the point we’re comparing to. If that is the case, how is voltage a difference while electrical potential is not?Drakkith said:Voltage is the difference in electric potential between two points, while electric potential itself is a way to define the electric potential energy of any charged particle placed in a specific field. Electric potential is the electric potential energy of a charged particle divided by the charge on that particle. Dividing by the charge gives you a way of characterizing the electric field itself, without need for a specific reference charge.
Basically, a charged particle with 2 coulombs of charge might have 10 joules of electric potential energy when placed in an electric field at point A. Dividing out the charge gives you 5 volts (joules per coulomb) of electric potential. At point B, the same charged particle might have 4 joules of electric potential energy. Dividing the charge out gives you 2 volts.
The voltage between points A and B is 5-2=3 volts. Note that volts is a unit of measurement, while voltage is not.
FS98 said:Isn’t electrical potential already relative? I thought we just generally use infinity as the point we’re comparing to. If that is the case, how is voltage a difference while electrical potential is not?
The "Potential" is defined relative to infinity. There is no confusion when you quote Potential (appropriately) but there is no experiment on Earth where a voltmeter can be connected to Infinity so the reference always has to be specified. Hence PD.FS98 said:Isn’t electrical potential already relative? I thought we just generally use infinity as the point we’re comparing to. If that is the case, how is voltage a difference while electrical potential is not?
Electric potential in a circuit refers to the amount of electrical energy that is available to be used by the electrons in a circuit. It is measured in volts.
Electric potential is a measure of the energy available to electrons in a circuit, while voltage is a measure of the force that pushes those electrons through the circuit. In other words, electric potential is the potential energy, and voltage is the measure of how much of that energy is being used.
Electric potential and voltage are directly proportional in a circuit. This means that as the electric potential increases, so does the voltage. This also means that if the electric potential decreases, the voltage will also decrease.
The unit of measurement for both electric potential and voltage is volts (V).
Resistors in a circuit can affect the electric potential and voltage by either reducing or limiting the flow of electrons. This means that resistors can decrease the voltage and electric potential in a circuit. The larger the resistance, the more it will impact the voltage and electric potential in the circuit.