Electromagnetic Induction
Contents
Key Stage 5
Meaning
Electromagnetic induction is the generation of an electromotive force (emf) in a conductor due to a change in magnetic flux.
About Electromagnetic Induction
- There are two physical laws governing electromagnetic induction.
- Faraday's Law states that the emf produced as a conductor experiences a changing magnetic field is proportional to the rate of change of that magnetic field with respect to time.
- Lenz's Law states that the direction of the induced emf is such that it opposes the change in flux that produced it (which is represented by a negative sign in the formula).
- Induced emf can be increased by increasing the rate of change of the magnetic flux, the number of turns in the coil, or the strength of the magnetic field|magnetic field.
- Electromagnetic Induction is a key principle in the operation of transformers, electric generators, and inductors.
Formulae
Electromagnetic Induction is described by Faraday's Law:
- \(\varepsilon=-\frac{\Delta\Phi}{\Delta t}\)
Where,
- \(\varepsilon\) is the electromotive force
- Ī¦ is the magnetic flux
- t is the time.
Additionally Ī¦ is given by:
- Ī¦=šµš“cosš
Where:
- šµ is the magnetic field strength
- š“ is the area of the coil
- š is the angle between the field and the normal of the area