SEP SUPERMAGNETS TEST KIT
322-034
SEP SUPERMAGNETS TEST KIT
This kit has been developed to support the activities described in the booklet ‘Supermagnets:
exploring the properties and uses of rare earth magnets’ published by the Science Enhancement
Programme. For details on how to obtain a copy, see the information at the end of this leaflet.
WHAT ARE SUPERMAGNETS?
Rare earth magnets or ‘supermagnets’ are the most
powerful ever made. The magnets in this kit are made
from an alloy of neodymium, iron and boron, and have
been put in plastic cases to make them suitable for
secondary school students to handle. The N and S
poles of these magnets are at the top on bottom of the
discs; the cases have been colour-coded – white for
an N pole at the face, black for an S pole.
HEALTH AND SAFETY
The strong forces produced by supermagnets can cause personal injury, physical damage to other
equipment or to the magnets themselves. Supermagnets are brittle and can break to produce
hazardous splinters. For example they may snap together suddenly and pinch your fingers or rapidly
move towards and collide with other objects. The protective plastic cases fitted on the supermagnets
reduce the risk of harm, but they must still be handled with care.
The strong magnetic fields produced by supermagnets may adversely affect some equipment that
relies on electromagnetic effects for correct and safe operation. Take care to keep supermagnets well
away from devices such as heart pacemakers, hearing aids, watches, identity and bank cards, mobile
phones, audio equipment, computer hardware (particularly disks and screens) and similar electronic
apparatus.
MEASURING FORCES OF ATTRACTION
The supermagnets kit can be used to measure
how the force of attraction between the magnets
varies with distance.
Fix a magnet in a white case (face pointing
upwards) at the bottom of the clear plastic tube
using the brass pin. Attach a length of thread to a
V-shaped clip and secure this to the magnet in
the black case. Slide the second magnet into the
clear plastic tube, pass the thread through the
blue plastic cap and push this on to the top of the
tube. Finally tie a loop at the end of the thread
and attach this to a newtonmeter held in a clamp
stand.
© 2010 GATSBY SCIENCE ENHANCEMENT PROGRAMME
SEP SUPERMAGNETS TEST KIT
322-034
To measure the force of attraction between the two magnets, the tube can now be pulled down slowly
until the magnets separate. By carefully observing the reading on the newtonmeter as the force is
increased, the force required at the point that they separate can be noted.
The plastic case is exactly 1 mm thick at the face
of each magnet, so the distance between them
initially is 2 mm. To increase the distance
between the magnets, insert plastic spacers
between the magnets. Each spacer is 1 mm thick.
At the start, the force decreases quite a lot for
each spacer added, so it is best to add just one at
a time; after the first few spacers it is better to add
more at a time.
MEASURING FORCES OF REPULSION
Also included in the SEP supermagnets test kit is
a loading pan and a piston that can be used with
two repelling magnets to measure how the force
of repulsion varies with distance.
Use the clear plastic tube and the magnet in the
white case as before. Attach the other magnet in
the white case to the end of the piston, and push
this into the clear plastic tube. The distance
between the magnets can be measured using a
small (15 cm) ruler. Note that the thickness of the
plastic at each of the faces is 1 mm. The force
can be increased by adding slotted masses to the
loading pan and the new distance between the
magnets measured.
Note that in this experiment, force is not measured directly – to convert the mass of the load added to
a force, students will need to know that a mass of 100 g exerts a force of about 1 N.
FURTHER INFORMATION
Other related practical
resources and copies of
the SEP publication
'Supermagnets: exploring
the properties and uses of
rare earth magnets' can
be purchased from
MiQGVHWV8./WG
www.mLQGVHWVRQOLQH.co.uk
© 2010 GATSBY SCIENCE ENHANCEMENT PROGRAMME
Visit the SEP website for
information on how to become
an SEP Associate and how to
obtain the downloadable
curriculum resources.
www.sep.org.uk