Physics - Chapter 23

23.1 §

• Electromagnetic Induction The process of inducing an electric current in a circuit using a changing magnetic field
• The term flux means flow
• Magnetic Flux - measure of number of magnetic field lines that pass through a given area
• Definition of a Magnetic Flux
  • magnetic flux = magnitude of magnetic field x area x cos $\theta$
  • SI Unit: T x m${}^2$ = weber (Wb)
• Magnetic flux depends on the magnitude of the magnetic field, it’s orientation, and the area of the surface
• Faraday’s law of induction
  • induced emf = -(# of loops) (rate of change of magnetic flux)
  • $ϵ$ = -N $\frac{△\varphi }{△t}$
• Lenz’s law states that an induced current always flows in a direction that opposes the change that caused it

23.2 §

• Electric Generator - A device that converts mechanical energy to electrical energy
• Electric Motor - A device that converts electrical energy to mechanical energy