Year 8 Term 1 - Magnetism

Question 1

Name 4 magnetic materials

Answer 1

Iron, cobalts, nickel, steel

Question 2

Name 2 non-magnetic materials

Answer 2

Copper & aluminium

Question 3

What’s the difference between a magnet and magnetic material

Answer 3

Magnetic materials only attract
Magnets attract and repel and have a north and South Pole.

Question 4

Where is magnetism strongest

Answer 4

At the magnet’s poles.

Question 5

Like poles always ….
Opposite poles always…

Answer 5

Repel
Attract

Question 6

Both poles always……..

Answer 6

Attract unmagnetised magnetic materials

Question 7

How do you induce poles

Answer 7

Temporary poles must be induced on unmagnetised magnetic materials when they are brought towards a magnet

Question 8

Is the force stronger or weaker the closer you are to a magnet

Answer 8

Stronger

Question 9

How do you know if a material is magnetic?

Answer 9

It attracts to the magnet

Question 10

How do you know if a material is not magnetic

Answer 10

The material neither attracts nor repels to the magnet.

Question 11

How do you test if a magnetic material is a magnet

Answer 11

Bring, in turn, a north and south pole close to the material, If it is a magnet, one side should attract and other repel, but if it is just an unmaAgnetised magnetic material it will attract from both sides.

Question 12

How do you investigate the variation of force with distance from poles (closer the stronger/weaker etc)

Answer 12

Use a balance; the pushing force is being measured so to get a higher reading you would need to hold the magnet further away
As the distance increases, the force on the magnet is not as strong

Question 13

What is a magnetic field?

Answer 13

The space around a magnet where the forces are felt

Question 14

Basic design of a magnetic field

Answer 14

Curves up out of north and into south
____________)
(. V
<—— out of north [. Magnet ] <—— into south
(. ^
~~~~~~~~~~~~
Curves up and out of north into south

Question 15

What is a compass

Answer 15

A bar magnet that is free to spin so that it lines up with magnetic fields

Question 16

How do you make a compass

Answer 16

Place a bar magnet on two watch glasses, and the magnet should spin and point due north due to the fact there is NO FRICTION.

Question 17

True or false: the earth doesn’t have a magnetic field

Answer 17

False

Question 18

What creates earths magnetic field

Answer 18

It is created by its liquid iron core spinning which lines up the magnetic particles.

Question 19

Which way does a compass point

Answer 19

Due north.

Question 20

How to make a permanent magnet

Answer 20

Take a hard magnetic material (e.g steel)and stroke it in one direction with the north end of a magnet

Question 21

How do you make a temporary magnet

Answer 21

You have to induce temporary magnetism - using another magnet (induce poles)
Take a soft magnetic material and attach a magnet to one end of it - when you remove it it goes back to being non magnetic

Question 22

How do you make an electromagnet

Answer 22

You need a direct current (battery) and wrap wire around the soft magnetic material (nail) and it creates a current.

Question 23

What is the difference between hard and soft magnetism

Answer 23

Hard magnetism is difficult to magnetise/demagnetise and soft magnetism is the opposite.
Hard magnetism: once it’s a magnet it stays a magnet.

Question 24

Give an example of hard magnetism

Answer 24

Cobalt

Question 25

Give an example of soft magnetism

Answer 25

Iron

Question 26

How do you destroy magnets (hard and soft)

Answer 26

Hard: heating and hitting
Soft: take magnet/current away

Question 27

What is the domain theory

Answer 27

Groups of atoms in each domain have their magnetic poles pointing randomly, but when magnetised all domain poles point in the same direction.

Question 28

What is the difference between a solenoid and electromagnet

Answer 28

Solenoids create a circular magnetic field whereas an electromagnet can be switched on and off,

solenoid is a coil of wire with no magnetic core but can still keep magnetism whereas an electromagnet is a solenoid with a magnetic core.

Question 29

Name 3 Uses of magnets

Answer 29

Navigation, attaching things, protection from ionising and radiation from the sun (earths magnetic field), good for making switches, lifting things, repulsing things,

Question 30

What is an independent variable

Answer 30

The variable that doesn’t change at all bc of other variables (the distance increases in the same amount each time)

Question 31

What is the dependent variable

Answer 31

The factor that changes due to other factors (mass reading changes bc distance increases)

Question 32

What is the control variable

Answer 32

Things that need to stay the same to make it fair (use the same block and magnet each time)