Teaching Minds-On Experiments on Electromagnetism in Secondary Schools Permanent magnets Magnetic construction sticks and balls (many small tasks, experiments)
Sticks - demonstrate that magnets have always two poles - sticks placed
by the same poles repel each other, but when stainless steel ball is
put between, they attract each other, the effect being caused by
magnetic domain re-ordering in balls.
The iron ball inserted between poles of different signs (the upper
figure) et magnetised in a "normal" way, becoming a two-pole magnet
(N-S), with the axis oriented in the direction of external magnets.
The ball between two poles of the same sign "accommodates" (the lower
figure) its magnetic poles in a way to be attracted by both external
magnets. We find the "missing” poles on a plane perpendicular to the
axis of magnets.
You can create amazing constructions out of those colourful sticks. But
at least every two magnets you have to place a metal ball between them.
If you don't, the whole thing will fall apart.
Now think carefully: magnet either repel each other or attract each
other. If one end of the stick attracts another stick, the other end of
the first stick should repel the second stick. And it would be so if we
didn't place the metal ball between the poles.