How exactly does an electrical circuit carry energy?
I understand that particles (protons and electrons) have “charge”, and opposite charges attract. And that electrons supposedly migrate very slowly along wires, and as they do so this creates an “electromagnetic field”.
What exactly is this electromagnetic field? What does that mean?
And if the electrons are not carrying the energy, how does it work? How does a circuit make a lightbulb glow at the atomic level?
In: Physics
A battery pushes electrons at one end of a circuit and pulls them at the other end. This gives direct current. A wall outlet goes back and forth between pushing and pulling, which gives alternating current.
Electrons hate each other and push away from each other. They love protons and pull toward them if they can. So whichever way the electrons are getting shoved, each one shoves on the next. They don’t move very much, but a wave of annoyance goes down the wire at nearly the speed of light. That wave is electric current.
In a lightbulb, there are electrons holding onto the protons in the filament in the bulb. If those electrons move, it also gets the protons moving, and the amount that they’re moving is heat.
As the filament heats up, it makes the electrons excited with energy, which pushes them away from their beloved protons. They get back toward the proton by releasing that energy as light.
So an incandescent lightbulb works equally well with direct and alternating current, because all that matters is how much the electrons are jostling around, not which way they’re going at any given moment.
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