Magnetic fields

A magnet produces an invisible region of force around it called a magnetic field. This field can push or pull certain materials without touching them. Magnetic field lines show the direction and shape of the field — they run from the North pole to the South pole outside the magnet.

Magnetic Materials

• Magnetic materials contain iron, nickel, or cobalt and are attracted to magnets.
• Examples of magnetic materials: iron nails, steel paperclips, steel screws, iron filings.
• Non-magnetic materials are NOT attracted to magnets.
• Examples of non-magnetic materials: plastic, wood, glass, aluminum, rubber, copper.
• Only a few metals are magnetic — most metals (like aluminum) are not.

Magnetic Poles

• Every magnet has two poles: a North (N) pole and a South (S) pole.
• The magnetic force is strongest at the poles.
• Opposite poles (N and S) attract each other — they pull together.
• Like poles (N and N, or S and S) repel each other — they push apart.
• If you break a magnet in half, each piece forms its own N and S poles.

Magnetic Field Lines

• Magnetic field lines are invisible but can be shown using iron filings on paper.
• Field lines exit the North pole and curve around to enter the South pole.
• Where field lines are close together, the magnetic force is strongest.
• Where field lines are far apart, the force is weaker.