Units (Magnetism & Electromagnetism)
5 marks · NormalTwo students set up the experiment shown.
Draw the magnetic field pattern expected between the two poles. Clearly label the direction of the field.
Explain why this arrangement produces a uniform magnetic field in the gap.
Work this out on paper, then compare with the answer and worked solution below. With a free account you can submit written answers for marking.
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(a) — · must show Straight, parallel, evenly spaced lines from N to S between the magnets; correct arrow direction N to S.
(b) A uniform magnetic field is created in the gap because the opposite poles are facing each other. This causes the field lines to be straight and evenly spaced, showing that the strength and direction of the field are the same everywhere in the region between the poles.
Must show: Straight, evenly spaced, parallel field lines from N to S between poles, Correct direction (N to S)
Common mistakes: Curved field lines instead of straight in the gap
Show mark scheme and worked solution
Marking points
D1 (a) · 1 mark · Straight, parallel, evenly spaced field lines shown in the gap between poles, from N to S.
D2 (a) · 1 mark · Correct direction arrows (from north to south).
B1 (b) · 1 mark · States field is uniform in strength and direction.
B2 (b) · 1 mark · Mentions straight, evenly spaced field lines.
B3 (b) · 1 mark · Opposite poles face each other: region between poles produces uniform field.
Worked solution
a) Draw straight, parallel field lines in the gap, all with arrows from north to south pole.
b) The arrangement means opposite poles face, so field lines go straight across the gap. Since the space is narrow, lines are parallel and evenly spaced, meaning the strength and direction of the field do not change (uniform field).