Magnets and Magnetic Fields
what is meant by a uniform magnetic field?
a field that exerts a constant force over a region
opposite poles _________
attract
if the magnet and magnetic material are brought _______ the induced magnetism will be ________
closer stronger
hard magnetic materials can be magnetised _______, and once magnetised can ______ ______ _________ __________
easily retain their magnetism permanently
is steel a hard or soft magnetic material?
hard
this magnetism has been ________ by the original magnet
induced
two examples of magnetic substances 'i____ and s_____'
iron and steel
Step 2) Investigating the shape and direction of the magnetic field of a bar magnet using plotting compasses
label the magnet's poles
magnetic field lines
lines that indicate the size, shape and direction of a magnetic field
soft magnetic materials are easily
magnetised and demagnetised
Step 4) Investigating the shape and direction of the magnetic field of a bar magnet using plotting compasses
mark the position of the head of the compass with a dot
Step 5) Investigating the shape and direction of the magnetic field of a bar magnet using plotting compasses
move the compass so the end of the compass needle matches up with the dot
magnetic field line arrows always point from ' _______ to ______'
north to south
soft magnetic materials - they will ___ _______ any _______ magnetism
not retain permanent
what does a uniform magnetic field consist of?
parallel, equally spaced magnetic field lines
Step 3) Investigating the shape and direction of the magnetic field of a bar magnet using plotting compasses
place a plotting compass near one pole of the magnet
Step 1) Investigating the shape and direction of the magnetic field of a bar magnet using plotting compasses
place the bar magnet in the middle of a piece of paper and trace the magnet's outline
magnetic fields
regions where magnetic materials experience a force
like poles _______
repel
Step 3) Investigating the shape of the magnetic field of a bar magnet using iron filings
scatter the paper with small iron filings
is iron a hard or soft magnetic material?
soft
Result - Investigating the shape of the magnetic field of a bar magnet using iron filings
the filings line up in the shape of the magnetic field
Advantage of using plotting compasses to investigate a magnetic field
they show the shape and direction of the magnetic field
Step 2) Investigating the shape of the magnetic field of a bar magnet using iron filings
trace round the bar magnet and then place the magnet under the piece of paper
placing the north and south poles of two permanent bar magnets near each other creates a ________ ______ _______ between the two magnets
uniform magnetic field
why can magnets also attract other magnetic substances?
(because) when a magnetic is brought near a magnetic material and when therefore the magnetic material is in a magnetic field, the material acts as a magnet
Step 6) Investigating the shape and direction of the magnetic field of a bar magnet using PLOTTING COMPASSES
Continue the process at different points along the magnet
Step 1) Investigating the shape of the magnetic field of a bar magnet using iron filings
Place permanent bar magnet on top of a piece of paper