A magnet pushes sideways on any wire carrying current. Bend the wire into a loop and its two sides get pushed in opposite directions — a twist. Then a tiny switch flips the current every half turn, so the twist never gives up. That spinning loop is the motor in your fan, drill, and toothbrush.
Most people picture a motor as something exotic. In fact it is one simple trick repeated — a magnet shoves a current-carrying loop, and a switch flips the current every half turn so the twist never gives up: push, flip, repeat.
What's actually happening
The discovery came in two halves. Ørsted found that current makes magnetism; Faraday, in 1821, closed the loop by showing a magnet pushes back — a current-carrying wire near a magnet feels a sideways shove, at right angles to both the current and the field. His first "motor" was a wire dangling in a cup of mercury, endlessly circling a magnet. The physics in your washing machine is that desk toy, civilised.
One straight wire only twitches. The engineering is in the loop: run the current up one side and back down the other, and the magnet shoves the two sides in opposite directions — a clean twisting force. But there's a catch the simulator shows you: once the loop turns ninety degrees, the twist has done its job and would happily stop there, rocking like a compass needle. The fix is the commutator — a split copper ring that swaps the current's direction every half turn, exactly at the dead spot. The push never learns it's been tricked. Push, flip, push, flip, thousands of times a minute.
Count the motors around you and you'll lose track fast: phone vibration, toothbrush, fans, pumps, hard drives, car windows, the compressor in the fridge. Modern brushless motors replace the mechanical flip with transistors doing the switching electronically — same trick, no sparks, which is why drones and EVs spin so smoothly. And the whole machine runs in reverse: spin the shaft yourself and the coil pushes current out instead. Every motor is a generator wearing different clothes, which is how an EV recharges its battery when it brakes.
There are more electric motors than people on Earth, and a motor is just a generator run backwards — which is how an electric car recharges when it brakes.
- 1Wind 10 turns of thin enamelled wire into a coin-sized coil, leaving two straight ends as an axle. Scrape the enamel off one side only of each end.
- 2Rest the axle ends in two bent paperclips stuck to a battery's terminals, with a strong magnet underneath the coil.
- 3Give it a nudge. The half-scraped ends act as a crude commutator — current flows for half of each turn, and the coil spins. You've built Faraday's legacy from pocket junk.
Common questions
After the loop turns 90°, the twist would stop at a dead spot. The commutator, a split ring, reverses the current's direction every half turn at exactly that point, so the push never learns it has been tricked.
It replaces the mechanical flip with transistors doing the switching electronically. Same trick, no sparks, which is why drones and electric cars run so smoothly.
Yes, run in reverse. Spin the shaft yourself and the coil pushes current out instead of consuming it — which is how an electric car recharges its battery when it brakes.