magnetism & electromagnetism Flashcards
(31 cards)
what is a magnet
A magnet is any material or object that produces a magnetic field.
what are the two poles on a magnet
north and south
what are some magnetic materials
cobalt,iron,nickel
draw magnetic field lines for a bar magnet
which way do the magnetic field lines go
from north to south
if the lines are closer together in a magnetic feild what is magnetic field like
its stronger
where is the magnetic field strongest
at the poles of the magnet
what is the force between a magnet and a magnertic material
always attractive
what do two un like poles do
attract
what do two like pole do
repel
how can you use a compass to show the direction of magnetic fields
inside compass - bar magnet
the north pole of the magnet is attracted to any south pole that is near so compass needle points in the direction of the magnetic field
move compass round magnet and trace needle position
what are the two types of magnet
permanent and induced
what are permanent magnets do
they create their own magnetic field
what do induced magnets do
they turn into a magnet when they are put into a magnetic field
what is the force between permanent magnets
always attractive
what happens to induced magnets when you take away the magnetic field
they loose all or most of their magnetism
what happens when a current flows through a wire
a magnetic field is created around the wire
if you change the direction of a current
the direction of the magnetic field changes
how to use the right hand thumb rule
put your thumb in the direction of the current ( up or down)
and then your fingers curl in the direction of the magnetic field
what is a solenoid
a coil of wire
how can you increase the strength of a magnetic filed that a wire produces
by wrapping the wire into a coil called a solenoid
why does solenoid increase the strength of a magnetic field
the field lines in each loop line up with each other which results in the field lines going in the same direction and are very close together
what is the magnetic field inside a solenoid like
strong and uniform ( same strength and direction in every point)
how can you increase the strength of a magnetic field in a solenoid even more
by placing a iron core in the centre
the iron core becomes a induced magnet
adding more turns around the magnet
