Unit 5Electricity & Magnetism

Standards - S8P5c - Magnetism, S8P5b - Electrical Circuits, S8P5c

- Electromagnetism

Magnets• Any material that attracts iron and materials

that contain iron.• The attraction or repulsion of magnetic

materials is called magnetism.• One part of a magnet will always point north

when allowed to swing freely.

Magnetic Poles• One of two ends of a magnet where the

magnetic effect is strongest.• North pole points north. Other pole is called

South pole.

Magnetic Interactions• Magnetic poles that are unlike attract each

other, and magnetic poles that are alike repel each other.

Magnetic Force• The attraction

or repulsion between magnetic poles; can cause an object to move.

Magnetic Fields• The area of magnetic force around a magnet.• Magnetic field lines are invisible lines that

map out the magnetic field around a magnet, and spread out from one pole, curve around the magnet, and return to the other pole.

• Magnetic fields can be single or combined.

Single Magnetic Field

Combined Magnetic Field

Magnetic Domains• A grouping of atoms that have their magnetic

fields aligned; acts like a bar magnet with a north pole and a south pole.

Alignment of Domains• In a magnetized material, all or most of the

magnetic domains are arranged in the same direction.

Magnetic Materials• A material that shows strong magnetic

properties is said to be a ferromagnetic material.

Making Magnets• Magnets can be

made from ferromagnetic material.

• They can be temporary (easily loses its magnetism) or permanent (keeps its magnetism for a long time)

• Magnets can be destroyed when they become un-magnetized by dropping, heating, or striking them.

• Magnets can be broken apart to have two smaller magnets with their own north and south poles

Changing Magnets