Lesson 1 Summary - Magnets and Magnetic Fields

Magnet

An object that attracts iron or iron-like metals.

Magnetic Poles

The two ends of a magnet, North (N) and South (S), where the force of the magnet is strongest.

Break a magnet

If you break a magnet into pieces, each piece will have both a North and a South pole.  It’s not possible to have a single magnetic pole.

Magnetic Force

The force of attraction or repulsion between two magnets, where like poles repel each other and unlike poles attract each other.

Magnetic Field

The area around a magnet where magnetic forces are exerted, allowing magnets to attract or repel without physical contact.

Earth's Magnetic Field

The magnetic field surrounding the Earth, influencing compass needles that point towards the Magnetic North Pole.

ferromagnetic elements

Materials that can be attracted to a magnet, such as an iron nail, or steel paperclip, are called magnetic materials.  They contain ferromagnetic elements, such as:

• Iron

• Nickel

• Cobalt

• Steel is not an element, but contains iron, and, as such, is ferromagnetic.

Magnetic Materials

Materials like iron, nickel, cobalt, and steel that can be attracted to magnets due to containing ferromagnetic elements.

Magnetic Domains

The magnetic poles of atoms within materials, where aligned domains create permanent magnets and misaligned domains result in nonmagnetic materials or temporary magnets.

Permanent non-magnet

• In a permanent nonmagnet, the magnetic domains are askew (all jumbled up).  Their magnetic fields cancel each other out, and no magnetism results.  Plastic pens, pieces of paper, and even people fall into this category.

Permanent magnet

lIn a permanent magnet, the magnetic domains are always aligned (all pointing in the same direction).  Their magnetic fields add to one another, and the item acts as a magnet.

Temporary magnets

Some materials have domains that are normally not lined up, but that can become lined up if a magnetic field is applied to them.

These objects (such as electromagnets, iron nails, and steel paperclips) are called temporary magnets. 

They are magnets for a short time only, and only when their magnetic domains are fully aligned.