How does an electric motor produce motion?
Electric current and magnetic forces can drive a rotating part. Discover why this takes more than two fixed magnets.
The short answer
An electric motor turns electrical energy into rotation. Current can make a coiled wire act as a magnet. Other magnets pull or push on this turning part.
The current direction is changed at suitable moments so the part keeps turning instead of stopping.
Equal-sized adult Wusels examine a stationary electric-motor model with a copper-colored coil and rotating axle behind glass. Invented museum setup; not verified wiring or a construction plan. The separate diagram explains a simple direct-current motor. AI-created illustration, not a photograph of nature.
What the diagram shows
The diagram simplifies the process. First compare its shapes and arrows. You can read its labels in larger text below.
Read the picture labels
These are the words and sentences from the diagram above. The full explanation follows below.
- Simple direct-current motor: switch poles at the right time
- 1. Angled
- Rotor can turn in the fixed poles’ field.
- 2. Aligned
- Without switching poles, it can stop here.
- 3. Poles switched
- Already slightly past the aligned position.
- N = north pole, S = south pole; the outside poles remain fixed. Like poles repel; unlike poles attract.
- Current in the coil switches at suitable points in the turn.
- The switching part is a commutator. The motor needs supplied electrical energy.
- Simplified view: rotor shown as a magnetic bar; wiring and contacts omitted. Not a construction guide. One simple rotor does not start from every position.
An imagined Wusel scene
Puschel and Flauschi investigate
Puschel draws the rotating part without a link to its power source. Flauschi traces current and magnets in the model. They add those before the motion arrow. Their sketch now explains the rotation rather than merely showing it.
Look closely
The Wusels examine a stationary motor in an invented museum model behind glass. Its copper-colored coil and rod-shaped rotating part help identify components. It is not verified electrical wiring. Use the labeled diagram for rotor poles and the sequence.
An example to help you understand
Make a paper comparison without electricity or real magnets. Draw a fixed N on the left and S on the right. N and S abbreviate the magnetic poles. In the middle, draw a rotating bar with N and S. Copy three states: angled, aligned, then with swapped rotor poles and slightly further round. Discuss what would happen without switching poles: the rotor could remain aligned. The last diagram state is already past exact alignment. A real rotor has motion and several technical parts; one simple rotor does not start by itself from every position. Paper does not move automatically: you are only representing the process.
Try explaining it
What does an electric motor turn into motion?
Choose a), b) or c), then explain your choice.
- a)The motion of a turning wheel.
- b)Electrical energy.
- c)Heat from the casing.
Show the explanation
Correct: b): Electrical energy.
An electric motor turns electrical energy into rotation. Current can make a coiled wire act as a magnet. Other magnets pull or push on this turning part.
The current direction is changed at suitable moments so the part keeps turning instead of stopping. Here electrical energy goes in and motion comes out. Generating electricity from motion reverses that transformation.
Word help
- rotation
- Turning around one's own axis.
- rotor
- A part of a machine that rotates.
- commutator
- A switch that changes the electrical connection at the right point in the simple motor’s turn.
- coil
- Wire wound into several turns. Current through it creates a magnetic field.
Explore in more detail
Here you will find longer explanations and further details. You can explore them together.
1. Current and magnetic force meet
Many electric motors combine current and magnetism. Electric charge is a property of tiny particles; charge can be positive or negative. Current means such charge moves. In a metal wire, mobile electrons carry it: tiny negatively charged particles. A force can then act on a suitable wire in a magnetic field. A magnetic field describes magnetic influence in space; it is not visible mist. Tiny hands do not push the wire. At the museum and on paper, we explore how this effect can be used for motion.
Checked against: [1]
2. One part stays, another rotates
In our simple example, a coil sits on a rotating axle. A coil is wire arranged in turns. Current makes it an electromagnet: a magnet whose effect depends on current. The rotating part is called the rotor. The stationary parts together are the stator. Magnetic forces can turn the rotor. A shaft here is a rod-shaped part that can pass rotation on to something else. Not every motor looks like this simplified example inside.
3. One pull is not enough
Every magnet has a north and a south pole. Opposite poles attract; matching poles repel. These forces can move the motor’s turning part, called the rotor.
If its magnetic poles stayed the same, the rotor could line up with the fixed magnets and stop. To keep turning, its magnetic effect must change at the right moment.
In a simple direct-current motor, a switch called a commutator does this. It changes the connection to the coiled wire. The current direction and the coil’s magnetic poles reverse while the rotor keeps turning. The source keeps its direction; the commutator swaps the connections to the coil.
4. Motion requires energy
An electric motor does not produce motion from nothing. It converts electrical energy into mechanical energy: energy useful here as rotation and work. In physics, work can mean a force moving something. Different motors use different arrangements of coils, magnets and control systems. Here, control means setting electrical actions appropriately. Some motors have permanent magnets in the rotor and current-carrying coils in the stator. Our diagram therefore explains one particular simple motor type, not every motor’s construction.
Checked against: [4]
An optional question for further exploration
You can use the longer explanation above. This is extra, not needed for the first quiz.
An extra question
Could two fixed magnets drive our motor forever without another energy supply?
Discover the answer
No. This motor needs electrical energy and suitable current connections. Unchanging magnetic poles can align; that does not produce endless rotation. An electric motor converts supplied energy.
Pictures and sources for adults
Sources for further reading
Facts checked against the specialist sources below on 12 October 2026. The Wusel scene is fictional; comparisons and simplified models are explicitly explained. Sources are in German and English.