Magnets & Magnetism

A magnet will pick up a nail, but not a penny because the nail

• has rust on it.
• is lighter than the penny.
• has a sharp point.
• contains iron.

This is a picture of a simple electromagnet. How can the electromagnet be made stronger?

• Add more coils of wire to the nail.
• Use a smaller battery.
• Reverse the poles of the magnet.
• Remove all the coils and the nail.

In magnetic materials, all of the ________ are pointing in the same direction.

• doors

• electrons

• domains

• orbits

If two magnets are close together, the magnetic force will be ________.

• smelly

• weak

• strong

• positive

Breaking a bar magnet in two creates

• A broken magnet with a N pole on one and a S pole on the other.

• Two smaller magnets with N and S poles.

• Two magnets that only repel.

• Two magnets that only attract.

A type of magnet that has temporary magnetic effect when electric current flows through it.

This refer to

• Electric

• Electronic

• Electrostatic

• Electromagnet

What do we use electromagnets for?

• Car engines

• Generators

• Speakers

• All of these!

The image above shows how iron filings respond to magnetic fields generated by two magnets with ____________ poles facing each other.

• opposite

• like

• positive

• negative

The diagrams show that electricity

• flows in an open circuit.

• has a magnetic field.

• gets stronger when a compass is close.

Although magnetic fields are _____________, one common way that people investigate them is to use ________ filings.

• invisible, iron

• touchable, iron

• invisible, plastic

• touchable, plastic