This week in the Ron Paul Curriculum physics course was an intro to the interplay between electricity and magnetism, and AC circuits.
Electromagnetic induction:
Just as a magnetic field exerts a force on a current carrying wire, making it want to move, if we move a wire through a magnetic field, it creates an electric current. This is electromagnetic induction. Current is produced if you move the conductor or the magnetic field.
Magnetic flux:
Magnetic field times the unit area perpendicular to the field.
Faraday’s low of induction:
If the flux through N loops of wire changes by an amount of delta Fee during a time of delta T the average emf is:
Lenz’s law:
An induced emf always gives rise to a current whose magnetic field opposes the original change in flux.
Two ways to change flux:
- Change magnetic field
- Change the area that is perpendicular to it.
EMF induced in a moving conductor:
Changing magnetic flux produces an electric field:
Field induction:
- An electric field is induces in any region of space in which a magnetic field is changing with time.
- A magnetic field is induced in any region of space in which an electric field is changing with time.
louisa neudorf 