Magnets and Electromagnets
Power a coil with a battery, add loops, flip the current and drag a compass to see the field.
Turn the battery up to make the coil an electromagnet. Add loops, flip the battery, or switch to AC. Drag the compass to see the field direction.
About the Magnets and Electromagnets
Free magnets and electromagnets. Power a coil with a battery, add loops, flip the current and drag a compass to see the field. Drag, change the sliders and see the result live. No sign-up, works on phone and computer. Built for physics, the magnets and electromagnets runs instantly in your browser: change a setting or drag an object and the result updates at once, so you learn by trying things out rather than only reading about them.
Power a coil with a battery, add loops, flip the current and drag a compass to see the field. Use it to explore physics ideas at your own pace, then check what you found against the key ideas further down this page.
How to use the Magnets and Electromagnets
- Use the controls to change Battery voltage, Number of loops, Source, Field lines. The simulation reacts instantly.
- Pick an option such as DC battery, AC (alternating), Show, Hide to switch modes or load an example.
- Where you see a glowing handle, object, weight or atom, drag it with your mouse or finger. Everything responds in real time.
- Watch the readouts and graphs update as you experiment, and compare what you see with the key ideas below.
Things to try
- Increase the loops to 4.
- Flip the battery voltage.
- Switch to AC.
Key ideas you can learn
- A current in a coil makes a magnetic field.
- More current or more loops make a stronger electromagnet.
- Reversing the current reverses the poles.
- AC makes the field flip back and forth.
Where this is used in the real world
Cranes, MRI machines, speakers, doorbells and relays all use electromagnets.
Who is this simulation for?
Physics students in middle school, high school and first-year university, teachers who want a quick demonstration for the projector, and anyone revising for exams. It works well for flipped classrooms because students can explore before the lesson.
For teachers: project it on the board, let students predict what will happen, then run it together. For students: change one thing at a time and write down what changes.
Frequently asked questions
How do you make an electromagnet stronger?
Increase the current, add more loops or use an iron core.
Why does the compass move?
The needle lines up with the magnetic field of the coil.
Is the Magnets and Electromagnets free to use?
Yes. It is completely free, with no signup, no download and no ads inside the simulation. It runs in your web browser.
Does the Magnets and Electromagnets work on a phone or tablet?
Yes. It uses touch as well as the mouse, so you can drag objects with your finger. A larger screen makes the controls easier to see.