Magnetic field’s strength decreases
as distance increases. In fact, a magnet’s power can all but disappear when
it’s moved even a slight distance away from the compass. However, stronger
magnets can continue to influence the direction of the compass’ needle from
greater distances away.
Why?
The bar magnets were competing with
the earth’s own magnetic field, which pulls the tip of the compass needle
north. As you scooted each bar magnet progressively closer to the compass, the
magnet’s field started to take over, pulling the needle slightly away from
north.
When you joined multiple bar magnets
together, you created one large super magnet that has the power of all of the
smaller magnets’ magnetic fields combined.
