P4.1 - Simple Phenomena of Magnetism

Question 1

What happens between unlike poles? [1]

Answer 1

they attract

Question 2

What happens between like poles? [1]

Answer 2

they repel

Question 3

What are the two poles of a magnet? [2]

Answer 3

North & South

Question 4

What is the force like between the poles if they are closer? [1]

Answer 4

it is greater

Question 5

What is a temporary magnet? [2]

Answer 5

can be magnetised and demagnetised very quickly and easily

Question 6

What is an example of a temporary magnet? [1]

Answer 6

iron

Question 7

What is a permanent magnet? [2]

Answer 7

• it keeps its magnetism even after the removal of their magnetic field
• it’s hard to magnetise

Question 8

What is an example of a permanent magnet? [1]

Answer 8

Steel

Question 8

What are the properties of magnets? [4]

Answer 8

• they have magnetic fields around them
• they have two opposite poles
• the exert little to no force on a non-magnetic material
• they attract magnetic materials by inducing magnetism in them

Question 8

What do strongly magnetic materials contain? [3]

Answer 8

• iron
• nickel
• cobalt
  (all or’s)

Question 8

How do we pass an electric current through the specimen? [3]

Answer 8

• place a steel bar in a long coil of wire
• pass a long direct current through it
• the coil has a magnetic effect which magnetises the steel

Question 8

What is an alternating current? [1]

Answer 8

it changes the direction of the electromagnetic field

Question 8

What does induced magnetism mean? [3]

Answer 8

process where any unmagnetised object gains temporary magnetic capabilities when put inside the magnetic field of a magnet

Question 8

What happens to the electrons as a magnet becomes de-magnetised? [2]

Answer 8

• get thrown out of line
• point to random directions again

Question 9

What is passing an alternating current through the magnet going to do to it? [1]

Answer 9

demagnetise the magnet

Question 9

What are the electrons like in an unmagnetised material? [1]

Answer 9

point in random directions

Question 9

What happens to the electrons as it becomes magnetised? [2]

Answer 9

they start to line up and act as one big magnet

Question 9

How do we de-magnetise a magnet? [2]

Answer 9

• hammer the magnet
• heat up the magnet to a high temperature

Question 9

What are ferromagnets? [2]

Answer 9

• hard magnetic materials
• difficult to magnetise but don’t lose their magnetism easily

Question 9

What are ferromagnets used for? [1]

Answer 9

permanent magnets

Question 9

What are some non-magnetic metals? [5]

Answer 9

• brass
• copper
• tin
• zince
• aluminium

Question 10

What is a magnetic field? [2]

Answer 10

the region around a magnet where it experiences a force

Question 10

How do you use alternating current to demagnetise? [1]

Answer 10

passing through AC through a coil placed near the magnet

Question 11

What happens to the magnetic fields when like poles are place near each other? [3]

Answer 11

• cancel each other
• there’s a neutral point
• combined field strength is zero

Question 12

What are the properties of field lines? [2]

Answer 12

• run from North pole to South pole
• it’s the strongest where the field lines are closer together

Question 12

What happens to the magnetic fields when unlike poles are place near each other? [2]

Answer 12

• magnetic fields combine
• produces a single field
• almost uniform strength

Question 13

What are electromagnets? [2]

Answer 13

type of magnet in which the magnetic field is produced by an electric current