Magnetism Review

What substance is attracted to a magnet?

• Silver
• Lead
• Water
• Iron

What characteristics do magnetic substances have?

• They can give a "shock" when you touch them.
• They can push or pull objects they are not touching.
• They are always black and cold to the touch.
• They fall faster than other objects when you drop them.

Ancient people discovered magnetic rocks called lodestone.  What did they use them for?

• To start fires
• Compasses
• Sculptures
• Telephone receivers

What must happen for an electromagnet to have a magnetic field?

• It must be heated.
• It has to be touching another magnet.
• It must be lined up with Earth's magnetic field.
• It must be connected to an electrical source.

What happens when two north poles of magnets are placed together?

• They repel.
• They attract.
• They cancel each other out.
• The strength of the magnet is doubled.

How is Earth's magnetic field similar to that of a magnet?

• It has North and South poles.
• It is hundreds of miles long.
• It is made in Earth's core.
• It is shaped like a horseshoe.

What is our best evidence that Earth has a magnetic field?

• All things fall toward Earth's center.
• A compass needle lines up with it.
• Winds blow from east to west.
• Earth's oceans all have currents.

This image correctly shows the shape of Earth's magnetic field.

• True
• False

This image shows the magnetic field of which kind of magnet?

• Bar magnet
• Horseshoe magnet
• Disc magnet
• Doughnut magnet

Earth's magnetic field and a bar magnet both attract particles to the same locations.  Where are they?

• The middle
• All around the outside
• The North and South poles
• First to the middle, then to the ends