Recently, we’ve been studying electricity at school and one thing I’m incredibly confused about is voltage. When I try to find explanations, I find people using analogies to give a basic idea but actually not explain what it is?
So far, I believe that Voltage acts like a pushing force force the current to flow. Is this correct? or Is there anything I’m missing.
In: Physics
A voltage is a difference in potential energy. It measures the amount of energy it takes to move a particle with an electric charge from one point in space to another. Moving a positively charged particle from a lower voltage to a higher one requires energy, and moving it back down releases energy. For a negative charge like an electron, this is reversed – going up in voltage releases energy.
There is a fundamental force in our universe that physically pushes positive particles towards negative ones, and this accelerates the particle, giving it kinetic energy. Voltage is a measure of how much energy is gained due to this force when a given amount of charge moves from one specific point in space to another. This is why 1 Volt is one Joule (measure of energy) per Coulomb (measure of charge).
As an example, if I allow one electron to flow from one side of a 1.5V battery to the other, I have moved -1.602×10^(-19) coulombs through 1.5 joules per coulomb. Multiplying these values gives you an amount of energy, and this is the kinetic energy gained by the electron as it moves.
As an aside, this is why voltage is always measured between two points in space. E.g. between two sides of a battery, between two charged plates, or between a live wire and the ground beneath it. A single point does not have a voltage, only a voltage relative to a specific other point.
The best analogy in my opinion is actually gravity. If I lift a heavy object up onto a table, this is akin to moving a positive charge up to a higher voltage. If the object is allowed to fall from the table, it will gain kinetic energy as it moves down. You could say the object doesn’t like being at a greater height, and it “wants” to move down. A positive charge “wants” to go down in voltage, too.
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