15. Magnetism Flashcards
What is a magnet?
Material that produces a magnetic field.
What is an electromagnet?
Material that only produces a magnetic field when current is flowing.
What always produces a magnetic field?
Permanent magnet.
What are the two types of magnets?
Permanent magnets and electromagnets.
What is magnetic force?
The attraction or repulsion of moving charges.
What is used to determine the direction of any of the variables of a positive charge?
Right hand rule.
What does a magnetic field represent?
The area where a force acts around, and within, a magnetic material, usually depicted by magnetic lines.
What is magnetic flux?
The number of field lines passing through a surface.
How is the magnetic flux calculated?
Sum of all normal components of the magnetic field through an area.
What is the magnetic flux through a closed surface?
Zero.
What does Faraday’s law predict?
Electromagnetic induction of a circuit.
When is an EMF induced?
When magnetic flux changes.
In Faraday’s law, the magnitude of electromagnetic force (EMF) is directly proportional to what?
The change in magnetic flux, and inversely proportional to the change in time.
