magnets are made from magnetic material.these are
metals that can be magnetised or will be attracted to
a magnet.most materials are not magnetic,but
iron,cobalt,nickel and steel are.
attract and repel
if you bring 2 magnets together 2 things can happen-attract or repel.
magnetic fields
magnets create magnetic fields.these cant be seen.they fill the space
around a magnet where the magnetic forces work,where they can attract
or repel
although we cannot see them,we can
detect them with iron filings.the tiny pieces
of iron line up in a magnetic field.
electromagnets
when an electric current flows in a wire it creates a magnetic field around the wire.by
winding the wire into a coil we can srengthen the magnetic field.electrommagnets are made
from coils like this.we can strengthen the electromagnet wrapping the coil around a iron
core.-adding more turns to the coil.-increasing the current.
magnetic field
the magnetic field of an electromagnet is like a bar
magnet one however it can change direction
unlike bar magnets that are permanent magnets,electromagnets can be
turned o and off by closing or opening the switch.
electric bells
electric bells have an electromagnet.
1)the current flows through the circuit,the electromagnet
makes a magnetic field.
2)electromagnet attracts the springly metal arm.
3)the arm hits the gong,which makes a sound.
4)the circuit is broken.the arm is out of position.
5)electromagnet turned off and the springly metal arm moves back.