Magnetism

Question 1

Name 3 types of permanent magnets.

Answer 1

1. Bar magnet
2. Horseshoe magnet
3. Ball magnet

Question 2

What are the 3 magnetic elements?

Answer 2

1. Iron (Fe)
2. Nickel (Ni)
3. Cobalt (Co)

Question 3

What is an alloy?

Answer 3

An alloy is a mixture of metals.

Question 4

What is Steel an alloy of?

Answer 4

Iron and Carbon.

Question 5

What are the two magnetic poles that a magnet has?

Answer 5

North and South pole.

Question 6

What would happen if you cut a magnet in half?

Answer 6

It would become two separate magnets, each with their own North and South poles.

Question 7

What is the Law of Magnetism?

Answer 7

The Law of Magnetism states that like poles (N-N, S-S) repel, and unlike poles (N-S, S-N) attract.

Question 8

What is a domain?

Answer 8

A domain is a region within in magnetic material that must be aligned to its other domains in order to become a magnet.

Question 9

Name 2 ways to make a magnet.

Answer 9

1. Stroking it with a magnet in the direction of its magnetic field
2. Placing it near a strong magnet

Question 10

What is the process of making a magnet called?

Answer 10

Magnetic Induction.

Question 11

How can a magnet be broken? Name 3 ways.

Answer 11

1. Heating it up
2. Hammering it continuously
3. Sending an alternating current (AC) through it

Question 12

What is a magnetic field?

Answer 12

A magnetic field is the space surrounding a magnet where the effect of the magnet can be detected.

Question 13

How can a magnetic fields direction be indicated?

Answer 13

With arrows.

Question 14

From where to where on a magnet does a magnet current flow?

Answer 14

From North to South pole.

Question 15

How can a compass be used to determine the direction of a magnet’s magnetic field?

Answer 15

A compass needle is a tiny magnet, therefore the pointer of the compass will always point to a magnet’s South pole, and away from a magnet’s North pole, indicating the magnetic field direction.

Question 16

Is Earth a magnet?

Answer 16

Yes.

Question 17

The Earth’s magnetic North pole is actually a _______ pole to a magnet.

Answer 17

South.

Question 18

The Earth’s magnetic South pole is actually a _____ pole to a magnet.

Answer 18

North.

Question 19

What is an electromagnet?

Answer 19

An electromagnet is a magnetic material that has become a temporary magnet because of an electric current flowing through it.

Question 20

What components are needed to build an electromagnet?

Answer 20

Conducting wire
Battery/cell
Iron nail/magnetic material

Question 21

What is created around a conducting wire when current flows through it?

Answer 21

A magnetic field.

Question 22

What is a solenoid?

Answer 22

A solenoid is usually a copper wire with many circular turns/coils that carry a current. The current creates a magnetic field, similar to that of a bar magnet.

Question 23

How can an electromagnet’s strength be increased? Name 3 ways.

Answer 23

1. Increasing the amount of turns in the solenoid
2. Increasing the current strength flowing through the solenoid
3. By placing a soft iron core inside the solenoid - soft means it can easily be magnetised

Question 24

Electromagnets can be turned ____ and ____. The ____ iron core becomes _____________ when there is no ______ flowing.

Answer 24

On.
Off.
Soft.
Demagnetised.
Current.

Question 25

Give 2 examples of the uses of an electromagnet.

Answer 25

1. Scrapyard - an electromagnet is used to pick up and move cars
2. Doctors/medicine - an electromagnet is used to surgically remove metal from patients.

Question 26

What is a relay switch?

Answer 26

A relay switch uses a small current in one circuit to active an electromagnet that closes a second circuit with a big current.

Question 27

What is a reed switch?

Answer 27

A reed switch uses pieces of magnetic material (reeds) with a gap between them, all enclosed in a glass tube.