Conceptual Physics-Magnetism Unit-Activities 1 and 2 Quiz Flashcards
Magnetic Domains
Groups of atoms with their magnetic poles lined up (based on how their electrons spin around them)
Magnetic domains line up with their blank and blank blanks facing the same direction in magnetized objects.
north and south poles
Magnetic domains do not line up in blank blanks.
unmagnetized objects
Magnetic objects can be demagnetized by being:
dropped
heated
hit
or otherwise (having their domains) “jumbled”
Objects such as pins can become magnetized if
their domains are lined up by a magnet.
What is the result of cutting a bar magnet in half?
You end up with two separate magnet, each with their own individual north and south poles.
A magnetic field can be created in a wire by
causing current to flow through it.
The strength of an electromagnet depends on the blank, blank, and blank.
current
number of loops
type of core
Magnetism is caused by
the motion of electrons
Magnetic objects are surrounded by
an invisible magnetic field
Earth is surrounded by its own
magnetic field
Universal Law of Energy… or whatever it is called:
Energy is not created or destroyed, but it can change forms.
Like poles…
repel
Opposite poles…
attract
The strength of a magnetic field includes both
distance and direction
The direction of a magnetic field at a specific spot is…
the direction that the north seeking pole of a compass will face if the compass were placed at that location.
What happens when a compass (that usually points north) is placed near a magnet or electromagnet?
it is deflected by the magnetic field of either the magnet or electromagnet, so that it (usually) doesn’t point north.
Describe what the magnetic field of a bar magnet looks like.
The field will be “pointing” away from the south pole, in a gradual arc to the north pole. IN other words, all the “arrows” in a diagram of the field should go from the south pole towards the north pole.
What effect does the electric current have on the wire?
It aligns the domains of the wire, aka magnetizes it.
How does the left hand rule work?
If you have a wire going straight in one direction, with current flowing from the negative end to the positive end, and you wrap (or imagine wrapping) your left hand around the wire, so that your thumb is pointing towards the positive end, the direction your fingers are pointing is the direction of the magnetic field around said wire.
So, for example, if the wire was pointing towards you, and the positive end of the wire was in your direction, the magnetic field should be flowing clockwise (from that perspective).
The magnetic field of a bar magnet is strongest at the blank(s).
poles
The magnetic field of a bar magnet is weakest at the blank(s).
middle
As you move away from a magnet, the strength of the field…
weakens
A compass is…
A free spinning magnet that aligns itself with the darts magnetic field.
If no magnet or electromagnet or large structure made of ferrous material.is nearby, compasses will always point…
north
Solenoid
current carrying coil of wire with many loops
Electromagnet
A solenoid with a ferromagnetic core (like iron)
How is an electromagnet different than a permanent magnet?
An electromagnet is a temporary magnet, a permanent magnet is… permanent.
An electromagnet is requires a power source/current, a permanent doesn’t.
An electromagnet can reverse polarity, but a permanent magnet cannot.
An electromagnet can vary its strength, but a permanent magnet cannot.
How can you increase the strength of a solenoid?
Add a better or improve the core
Add more coils or layer the coils
Increase the current
How does increasing the number of coils increase the power of an electromagnet?
Increases number of domains
How does increasing the current increase the power of an electromagnet?
By aligning the domains better
How does the core affect the electromagnet?
It amplifies the fields, if it is ferromagnetic.
