How Does Electricity Work?

How Does Electricity Work?

Electricity works using three forces:

  1. Voltage
  2. Amps
  3. Resistance

These three forces work as a unit inside of a given electrical circuit to allow the free flow of electricity from one place to another.

Electricity and the process of transferring electricity begins when an atom’s electrons are excited into action and start to move in what we call a “current” or flow. Different items are better or worse at conducting an electrical force due to this atomic action. If an atom holds tight to its electrons (meaning the electrons are really close to the nucleus) then it won’t be as conducive to the flow of electricity as an atom that keeps its electrons further away from the nucleus.

This is why certain materials (metals like silver, gold, and aluminum) are good conductors of electricity. They are made up of these types of atoms that don’t hold tight to their electrons. When we think of materials that aren’t conducive to electricity, we think of glass, plastic, and even the air. These items are called “insulators” and the makeup of their atoms obstructs electrical current flow.

Voltage and Circuits

How Does Electricity Work?

How Does Electricity Work?

Now that we understand electricity at a molecular level, let’s take a look at the physical process of electricity. Electrons, even though they are tiny, need some sort of force to keep them moving in a current, just like a stone needs to be pushed to roll down a hill. The force that moves electrons in a current is called electromotive force, or “EMF”. The term you may have heard to describe EMF is “voltage”.

This voltage is carried along a circuit. An electrical exchange is made up of an electrical source, something called a load, and at least two wires that carry the current between the electricity’s source and the electrical load. Imagine our electrical source is a battery and the electrical “load” is a light bulb screwed into a desk lamp.

All electrical sources have a positive and a negative terminal. The negative terminal is the part of the circuit that is used to push electrons along the electrical circuit. The wire running from the negative terminal is attached to the load (in our example the load is a light bulb), and then that same wire runs from the load back to the positive terminal attached to the source. The amount of force applied by the electrical source is what determines how much voltage moves through the electrical circuit. The word “amps” refers to the amount of electrons moving through this electrical circuit. The word is “amperage” and is a measure of electrical current.


The final aspect of electricity you need to understand is called “resistance”. Think of water running through a pipe. The larger the pipe the easier it is for water to move through that pipe. Pushing a million gallons through a garden hose would take longer than letting the same amount of water run through a canal.

When the electrical current enters the “load” part of an electrical circuit (like our light bulb) some aspect of the load takes on the same amount of current. In a light bulb, the little filament wire inside the bulb becomes as electrically charged as the wire that’s moving the electricity.

When the electrical current flows through the light bulb’s filament, the electrons of the atoms of the current become really thick because they’re moving through a smaller space — like water building up behind a dam. Just like the small space of a dam reservoir holds back water, the small space inside the filament greatly increases the energy of the electrons. This buildup of energy is what lights up the light bulb.

Voila!  That’s how electricity works.

Want to learn more about how electricity works? Take a look at Electricity Demystified, available at Amazon. (We make a tiny commission if you buy a copy via our link.)

This is part of a series of blog posts we’re publishing about How Stuff Works. The other posts in this series include: