Magnetic Field Diagram
Free printable magnetic field diagram — a bar magnet with its north and south poles and the curved field lines that run between them, with labels and direction arrows. Download PDF or PNG for Letter paper.
The magnetic field of a bar magnet
Every magnet is surrounded by an invisible magnetic field. This diagram shows the field of a bar magnet, drawn as curved field lines running from the north pole to the south pole. Here is what happens at each labeled part of the diagram:
| Part | What it does | Why it matters |
|---|---|---|
| North pole (N) | One end of the magnet. Outside the magnet, magnetic field lines point away from the north pole. | Field lines fan outward from the north pole like water spraying from a hose — without a source end to push the field out, there would be no directed force and magnets couldn't attract or repel anything. |
| South pole (S) | The other end of the magnet. Field lines point back into the south pole. | Every field line that leaves the north pole must return somewhere, and that somewhere is the south pole. Slice a bar magnet in half hoping to isolate just one pole and you'll always get two new poles — nature never allows a loose end. |
| Magnetic field lines | Curved lines that show the shape of the field. They are closest together near the poles, where the field is strongest. | Where field lines bunch tightly together, the force is strong enough to lift a paperclip or deflect a compass from across a table; where they spread far apart, the force has faded to nearly nothing. Engineers use this crowding pattern to design speakers, motors, and MRI machines that need precise control over where magnetic force acts. |
| Direction of the field | Outside the magnet, the field always points from the north pole to the south pole. | Knowing the direction lets you predict whether two magnets will attract or repel before they ever touch — north-to-south always attracts, while two north poles facing each other means field lines pointing away from each other, producing a push. That invisible direction is also what steers compass needles toward Earth's geographic north, guiding navigation for centuries. |
Companion worksheet
A free fill-in worksheet with an answer key, built from the labels above — students match each part to its description, then answer a couple of short questions. Great for a quick check after using the diagram.
How to print
Choose Download PDF for a ready-to-print file that fits US Letter paper (8.5 × 11") in landscape, or Download PNG for the high-resolution image.
Frequently asked questions
Which way do magnetic field lines point?
Outside the magnet, magnetic field lines always point from the north pole to the south pole. Inside the magnet they run from south to north.
Where is a magnetic field strongest?
A magnetic field is strongest near the poles of the magnet, where the field lines are closest together.
What paper size should I print this on?
The diagram is sized for standard US Letter paper (8.5 × 11") in landscape orientation. Use "Download PDF" for a print-ready file that fits the page automatically.