4.7.1.2 Magnetic Fields

Question 1

Magnetic field:

Answer 1

the region around a magnet where a force acts on another magnet or on a magnetic material e.g. iron, steel, cobalt and nickel is called the magnetic field

Question 2

What is the force between a magnet and a magnetic material?

Answer 2

the force between a magnet and a magnetic material is always one of attraction

Question 3

What can be used as a test for a permanent magnet?

Answer 3

repulsion

Question 4

What does the strength of the magnetic field depend on?

Answer 4

• the strength of the magnetic field depends on the distance from the magnet
• the field is strongest at the poles of the magnet

Question 5

What is the direction of the magnetic field?

Answer 5

• the direction of the magnetic field at any point is given by the direction of the force that would act on another north pole placed by that point
• the direction of a magnetic field line is from the north (seeking) pole of a magnet to the south (seeking) pole of the magnet

Question 6

How does a magnetic compass work and what does it contain?

Answer 6

• a magnetic compass contains a small bar magnet
• the Earth has a magnetic field
• the compass needle points in the direction of the Earth’s magnetic field

Question 7

Describe how to plot the magnetic field pattern of a bar magnet:

Answer 7

• place plotting compass near north/South Pole of magnet and mark direction that the compass points
• move plotting compass around the bar magnet to the other pole marking at regular intervals the direction the compass points
• join points up and add an arrow pointing from N to S pole