Magnetism.

Question 1

Magnets have 2 poles. Name them.

Answer 1

North and south poles.

Question 2

North and south pole will _____ each other.

Answer 2

North and south pole will attract each other.

Question 3

Two north poles or two south poles will ______ each other.

Answer 3

Two north poles or two south poles will repel each other.

Question 4

Magnets attract what kind of materials?

Answer 4

Ferromagnetic materials.

Question 5

Name 4 ferromagnetic materials.

Answer 5

Iron, nickel, cobalt, and steel.

Question 6

What happens when ferromagnetic material is placed next to a magnet?

Answer 6

Magnetic poles are induced in it (it turns into a magnet temporarily, so it can attract the magnet next to it).

Question 7

True or False. Ferromagnetic objects can be hung in a chain from a magnet.

Answer 7

True.

Question 8

Define magnetic field.

Answer 8

A magnetic field is an area around a magnet where a magnetic force has an effect on magnetic materials.

Question 9

Where do magnetic fields point from?

Answer 9

North to South.

Question 10

Magnetic field lines touch each other. True or False.

Answer 10

No, magnetic field lines do not touch each other.

Question 11

Where is the magnetic field strongest?

Answer 11

The magnetic field is strongest where the lines are the closest together.

Question 12

What does the Law of Magnetism state?

Answer 12

The Law of Magnetism states that like poles repel and unlike poles attract.

Question 13

Define magnetic forces.

Answer 13

Magnetic forces are non-contact forces that cause movement.

Question 14

What can be used to measure the magnetic force of attraction?

Answer 14

A forcemeter can be used to measure the magnetic force of attraction.

Question 15

What is a compass?

Answer 15

A compass is a tiny magnet. It points towards the South pole, and away from the North pole of a magnet.

Question 16

What can we use a compass for?

Answer 16

We can use compasses to find out what a magnetic field looks like.

Question 17

The Earth has a ________ _______. There is a lot of liquid ____ in the Earth’s ______ _____. As it moves around it makes a ______ ______.

Answer 17

The Earth has a magnetic field. There is a lot of liquid iron in the Earth’s outer core. As it moves around it makes a magnetic field.

Question 18

• What does the Earth’s magnetic field protect us from?
• What would happen if the Earth’s magnetic field did not protect us from these things?
• Name an example of this.

Answer 18

The Earth’s magnetic field protects us from the Sun’s cosmic rays which would destroy our atmosphere (this may have happened to Mars).

Question 19

Define electromagnets.

Answer 19

Electromagnets are magnets which can be switched on and off with electricity.

Question 20

When the electricity is on, what is the electromagnet doing?

Answer 20

When the electricity is turned on, the electromagnet is on too. It behaves the same as a regular magnet.

Question 21

When the electricity is off, what is the electromagnet doing?

Answer 21

When the electricity is off, the electromagnet is also off. It is not a magnet anymore, just a piece of iron.

Question 22

What is an electromagnet made of?

Answer 22

An electromagnet is made of a piece of iron, in a coil of copper wire (the wire carries the electricity).

Question 23

How can you make an electromagnetic stronger? Name 3 ways.

Answer 23

• Increase the number of turns of the copper coil.
• Increase the voltage of the electric current.
• You can use a different core (it can be a bigger core or different ferromagnetic material).

Question 24

Define neutral or null point.

Answer 24

A neutral point of a magnet is defined as a point at which the resultant magnetic field is always zero.

Question 25

Define magnetic field strength.

Answer 25

Magnetic field strength measures how strong a magnetic field is.

Question 26

How can you test for the north pole of an unmarked magnet?

Answer 26

Collect a compass and your unmarked magnet.
Place the compass on a table and lay a magnet on the table.
Bring your magnet next to your compass. look at the compass needle.
Since the compass needle is a small magnet, the south end will be attracted to the north pole of your magnet.

Question 27

How can you test for the like poles of an unmarked magnet?

Answer 27

Place both of your unmarked magnets together.

If they are attracted they are unlike poles but if they repel they are like poles.

Question 28

An iron nail is attracted which to pole of a magnet.

Answer 28

Only the north pole.

Question 29

Why do we repeat experiments?

Answer 29

To make the results more accurate and reliable.

Question 30

How can we make results more reliable?

Answer 30

By repeating experiments.