in this experiment you can create some magnetism
from electricity. you will require insulated
copper wire used for motor winding, a needle,
razor blade and a battery. first take copper
wire which is used in motor winding and a
make a coil with 40 turns. use 25 gauge wire.
and then with a blade scrape both the ends
to remove the insulation so that you will
see shiny copper on both the ends. then take
a square piece of rubber and make a long slit
in it. the purpose of the slit is that you
can take a coil and insert it and make it
stand vertically. now if you take a fresh
blade hanging by a thread, you will be surprised
that all blades are pre magnetized and point
towards north and south. if you hang a needle
same thing happens. the needle also points
north and south. now take your blade and hang
it by a very thin thread in the middle of
the coil such that the blade can rotate very
freely. take a torch battery of 1.5V and attach
both the ends of coil to the plus and minus
of the battery. you will be surprised that
the blade just turns at right angles because
the coil has become a magnet and it repels
the blade magnet and it comes at right angles.
now invert the terminals of the battery.the
plus becomes minus and minus becomes plus.
once again when you connect, the blade turns
the opposite way. now the blade is once again
at right angles to the axis of the coil. you
can repeat the same experiment using a needle,
because the needle is also pre magnetized.
the needle also comes at right angles to the
axis of the coil.
