Magnetism Flashcards
What is the definition of Magnetic fields?
A region in space where an object (with certain properties) will experience a force.
Three objects with (what?) certain properties experience forces in what type of fields?
All objects with mass experience a force of attraction in gravitational fields.
Charged objects experience a force in an electric field.
Magnetised objects and moving charges experience a force in magnetic fields.
What type of magnet has strong magnetic fields around it?
Permanent magnet
Materials that are attracted to magnets are called …
Magnetic
What 3 metals can be magnetised?
Iron (Fe)
Cobalt (Co)
Nickel (Ni)
Term for:
Materials that have magnetic properties, can be magnetised and are strongly attracted to metals.
Ferromagnetism / Ferromagnetic
Definition of domains
Magnetically aligned regions within ferromagnetic materials.
Domains are never randomly arranged. T/F
Domains are the result of many unpaired electrons preferring to stop spinning. T/F
FALSE: Domains are USUALLY randomly arranged.
FALSE: Domains are the result of many unpaired electrons preferring to ALIGN THEIR SPINS.
What does it create when magnets have their domains aligned?
A net magnetic field.
What can you do to randomise a magnets domains?
Heating it.
Dropping it.
Can ferromagnetic materials become
temporary/ permanent magnets?
Yes, by exposing the ferromagnetic material to external magnetic fields. This will align the materials domains parallel to the external magnetic field.
Magnets have a … and … pole.
There are monopoles in nature. T/F
The fundamental building blocks of magnets are spinning electrons. T/F
North and South Pole.
FALSE: There are NO monopoles in nature.
TRUE: The fundamental building blocks of magnets are spinning electrons.
Where, in the drawing of a magnet, is there a strong magnitude/high density and weak magnitude/low density?
Strong m/High d: As the field lines come out of the North Pole and go into the South Pole.
Weak m/ Low d: Halfway between the North and South poles.
Direction of the field lines around and inside a magnet?
Field lines travel from North to South outside the magnet.
And from South to North inside the magnet.
Like poles …
Unlike poles …
Like poles repel.
Unlike poles attract.
If the Earth was a bar magnet the Earths geographical North Pole is a bar magnets … Pole.
Earths geographical North is a bar magnets South Pole.
Is Earths geographical North Pole the same as the Magnetic North Pole?
No, there’s 11.5 degrees different.
Earths geographical North Pole we call true North.
What is magnetic flux?
The number of field lines drawn crossing a given two dimensional surface.
It is used to measure the strength of the magnetic field.
What is formed when the magnetosphere deflects the solar wind which then collides with the atmosphere.
Aurora Australis
Explain the domain theory of magnetism…
Electrons spin so that atoms in ferromagnetic materials behave like small magnets, these “magnets” magnetic fields point in all directions.
When they become aligned they form small regions of stronger magnetism, called magnetic domains.
When all the domains are magnetically aligned the subject as a whole becomes magnetized.
Briefly explain what happens when two metal spheres with different charges are brought together.
Electrons are transferred between the spheres during
contact and the spheres acquire equal like
charges and therefore repel each-other.
Define the Voltage of a battery.
The total energy provided by the cell per
unit charge.
How do we create permanent/temporary magnets?
By exposing ferromagnetic materials to external magnetic fields.
