- When the magnetic flux through a coil changes with time, an EMF is generated within the coil.
- This EMF creates a current, which in turn produces a magnetic flux which opposes the changes to the original flux. (Lenz’s Law).
If the magnetic flux changes over time, then the average EMF produced is:
Faraday’s Law for moving conductors
- When a straight conductor is moved through a magnetic field, an EMF is produced between its ends.
- The conductor must cut through field lines
- Max EMF occurs when it moves perpendicular to the field
EMF = lvb
- l = length of conductor
- B = magnetic flux density
- v = velocity of the conductor
If flux is at an angle, EMF = lvB sinθ where θ = angle the conductor makes with the flux