6 Magnetism Flashcards
What are the ends of a bar magnet called?
north pole
and
south pole
Where is the magnetic field the strongest around this bar magnet?
How can we tell this from the magnetic field lines?
Magnetic field is strongest at the poles
because
Field lines are close together indicating a stronger field.
How can you create a uniform field using two bar magnets?
Place the N pole of one magnet facing the S pole of the other.
Move them so that they are close but not touching
There is a uniform field between the poles
Describe the magnetic field created when the N-pole of one bar magnet is near the S-pole of another.
Uniform field
Magnetic field lines are parallel AND evenly spaced
What is a magnetic field?
A region of space where a magnetic material experiences a force.
Draw an attracting field between a North and South pole.
Draw a repelling field between two N-poles
Name a metal which is magnetically hard.
Steel
Name a metal which is magnetically soft
iron
What is the point called between two N-poles of a magnet where their magnetic field cancels?
neutral point
What is the law of magnetism?
Like poles repel
Unlike poles attract
What is the difference between the domains in a magnetically hard material and a magnetically soft material?
Magnetically hard- difficult for domains to align in a field (also difficult for domains which are lined up to de-align)
Magnetically soft- easy for domains to align in a magnetic field and then de-align when field is removed.
What is a permanent magnet made of? Magnetically hard material or magnetically soft?
Magnetically hard- so that it does not lose its magnetism easily
How can you observe THE SHAPE of a magnetic field around a magnet?
- Pace paper over top the magnet
- Sprinkle iron filing on the paper
- Tap the paper to help the iron filings line up in the field
What happens when an iron nail is brought near the N Pole of a magnet.
The nail is attracted to the N-pole
A magnetism is induced in the nail because it is made of iron.
What is the difference in the orientation of the domains in a magnetised and demagnetised material?
Magnetised- domains are lined up
De-magnetised- domains are randomly arranged
How can you show the shape AND direction of a magnetic field around a magnet?
- place a magnet on a piece of paper
- place a plotting compass at one corner of the N-pole of the magnet
- draw a dot where the compass is pointing.
- move the compass forward so that the tail is adjacent to the point you just plotted
- draw another dot where the compass is pointing
- Continue this until you reach the S-pole and connect the dots with a smooth curve.
- Repeat steps 3-6 drawing multiple field line around the magnet
How can an iron nail be magnetised?
Stroke the iron nail with a magnet for several minutes.
This will align the domains in the iron nail and magnetise it.
How can you demagnetise a permanent magnet?
Heat it, hammer it or drop it repeatedly.
In which direction do magnetic field lines point?
North to South
What 3 materials can be magnetised?
Iron (and steel as it contains iron)
Cobalt
Nickel
