7.1 Magnets and magnetic fields
9 exam questions worth 21 marks. Write your answer, open the mark scheme, then give yourself the marks you earned. Your answers are saved on this device.
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What happens when the north poles of two magnets are brought close together?
Choose one answer.
Correct Not quite: the answer is They repel
Mark scheme
B: They repel
Model answer
They repel (B).
Which of these materials is magnetic?
Choose one answer.
Correct Not quite: the answer is Nickel
Mark scheme
C: Nickel
Model answer
Nickel (C).
State the difference between a permanent magnet and an induced magnet.
Mark scheme
a permanent magnet produces its own magnetic field all the time (1); an induced magnet is only magnetic when it is in a magnetic field / loses its magnetism when removed (1)
Model answer
A permanent magnet always produces its own magnetic field. An induced magnet is only magnetic while it is in another magnetic field.
Explain why a piece of unmagnetised iron is always attracted to a magnet.
Mark scheme
the iron becomes an induced magnet (1); the pole nearest to the magnet is opposite to the magnet's pole (1); unlike poles attract (1)
Model answer
The iron becomes an induced magnet, with the nearest pole being opposite to the magnet's pole. Unlike poles attract, so the force is always attraction.
A student finds that one end of a metal rod is attracted to the north pole of a magnet. Explain why this does not prove that the rod is a magnet, and describe a better test.
Mark scheme
an unmagnetised piece of iron / steel is also attracted (1); test: see if the rod is repelled by a pole of a magnet (1); only a magnet can be repelled (1)
Model answer
An unmagnetised piece of iron would also be attracted. A better test is repulsion: if the rod end is repelled by the magnet's pole, it must be a magnet.
State what the direction of a magnetic field line shows, and what the spacing of the lines shows.
Mark scheme
the direction of the force on a north pole (from north to south) (1); lines closer together means a stronger field (1)
Model answer
The arrow shows the direction of the force on a north pole, from north to south. Lines that are closer together show a stronger field.
Describe how to use a plotting compass to find the shape of the magnetic field around a bar magnet.
Mark scheme
place the magnet on paper and the compass near one pole (1); mark the position of the ends of the needle (1); move the compass so the tail is at the tip's previous position and repeat (1); join the dots to draw a field line and add an arrow from north to south (1)
Model answer
Put the bar magnet on paper and the compass near the north pole. Mark the ends of the needle, then move the compass so that its tail is at the last mark, and repeat. Join the dots to form a field line and add an arrow from north to south.
Describe what the field is like between two opposite poles that are close together, and give the name for this kind of field.
Mark scheme
lines are parallel and equally spaced / straight lines from north to south (1); a uniform field (1)
Model answer
The lines are straight, parallel and equally spaced, so the field is uniform.
A compass needle points towards the geographic north. Explain what this shows about the Earth.
Mark scheme
the Earth has a magnetic field (1); the north-seeking pole of the needle is attracted to a magnetic south pole (1); near the geographic North Pole (1)
Model answer
It shows that the Earth has a magnetic field. The needle's north pole is attracted to a magnetic south pole, which is near the geographic North Pole.
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