ELi5: can someone give me an understanding of why we need 3 terms to explain electricity (volts,watts, and amps)?

Read the Story

Show Top Comments

Think of a pipe that we’re going to pump water through. Now imagine you put your face at the open end of the pipe. The voltage is the pressure the pump puts in. The pressure will drop depending how long the pipe is. The current is the amount of water that moves through the pipe per second, the flow rate. The watts is how hard it hits you in the face, or how much it pushes you back. I could send a low pressure and high flow rate and you’d have a shower. Or I could send a high pressure and the same flow rate and pressure wash your back deck.


Because they are different things. We aren’t Squanchy speaking in squanch. Voltage is the charge difference between two things. Current is the flow of electrons, measured in Amperes. Watts are the combined measure of the two for power. Volts x Amps = Watts.


The three terms we actually need are volts, amps, and *resistance*, which is opposition to current flow (amps). The reason we need these three terms to talk about electricity is because they are dependent upon each other. If you have a known voltage, the amount of current that will flow is dependent upon the resistance. More resistance = less current flow. Less resistance = more current flow. Power (in electrical terms) is the ability to do work, and is calculated by multiplying volts times amps. It actually gets a little more complicated than that but that’s the basic equation.


Amps (Amperage) is how many pixies there are. Voltage is a measure of how angry said pixies are. Devices choreograph the pixies and make them dance. Wattage is how many pixies dance in a given time. DC pixies always go in a circle from negative to positive. AC pixies frolick back and forth. Pixies always want to dance and go to sleep in the ground. No matter how angry the pixies are, there have to be enough of them to hurt you.


If electricity was a waterfall, then volts would tell how high it is, amps how wide it is and watts how much water goes over the edge per second.