Unit 23 - Electromagnetism Flashcards
What is electromagnetism ?
When a charged particle move, it creates a magnetic field. Therefore, when a current pass through a wire a magnetic field is produced.
How to work out radius of the charged particle in a magnetic field?
r = mv / BQ
What is a velocity selector?
A device that uses both electric and magnetic fields to select
What is magnetic flux?
The product of the component of the magnetic flux density perpendicular to the area and cross-sectional area.
What is Faraday’s law?
The magnitude of the induced e.m.f. is directly proportional to the rate of change of magnetic flux linkage
What is Lenz’s law?
The direction of any induced emf or current is always in a direction that opposes the change that producing it
What is the link between flux linkage-time graph and e.m.f-time graph?
e.m.f = -gradient of flux linkage-time graph
