Magnetism and Electromagnetism
4 marks · EasyThe diagrams below show two ways of producing a uniform magnetic field using two bar magnets. One shows the north pole of one magnet facing the south pole of the other with a small gap between them.
Describe the magnetic field in the region between the two poles.
How could you recognise that the field in this region is uniform?
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.
Show answer
(a) The field between the poles is a uniform magnetic field with parallel, evenly spaced straight field lines from north to south.
(b) You can recognise a uniform field because the field lines are parallel to each other and equally spaced throughout the region.
Common mistakes: Thinking the field is strongest near the centre only, or that uniform means no field
Show mark scheme and worked solution
Marking points
B1 (a) · 1 mark · Mentions the field is uniform or the field lines are straight and parallel.
M1 (a) · 1 mark · Mentions field lines are evenly spaced or go from north to south between the poles.
B2 (b) · 2 marks · Says field lines are parallel (1) and equally spaced (1) as recognition of a uniform field.
Worked solution
a) The region between the opposite poles shows a uniform magnetic field. The field lines are straight, parallel and evenly spaced, going from the north to the south pole.
b) A uniform magnetic field is recognised by straight, equally spaced, parallel field lines in the region.