Magnetic field & field lines
Outside a bar magnet, field lines leave N and enter S; the tangent gives B direction.
Magnetism & inductionB-fields, Ampere force, Faraday/Lenz, and AC basics.
Start here
Magnetic field & field lines
Magnetic field around current-carrying wire. This “Magnetic field & field lines” page is an MVP interactive sketch — formulas, controls, and live readouts in the browser; a fuller bench may follow.
Magnetic field around current-carrying wire.
Key formulas
B=\mu_0I/(2\pi r)\Phi=BS\cos\theta
How to use
- Adjust parameters in the left panel.
- Use play / pause and speed controls.
- Match right-side readouts to the formulas.
- Reset to return to the initial state.
Applications
- Magnetic field & field lines: Magnetic field around current-carrying wire.
- Classroom focus: the tangent gives B direction.
FAQ
What does MVP mean on this page?
An interactive sketch with formulas and parameters. Polished Ready labs are the full bench experience.
What does the “Magnetic field & field lines” lab practice?
Tune parameters and match readouts to the “Magnetic field & field lines” relations — useful for prep and demos.
How do I find the Ampere force direction?
Left-hand rule: B into palm, fingers along I, thumb along F.
When is there an induced current?
When flux through a closed loop changes, or a conductor cuts field lines.