MAGNETIC INDUCTION

• Michael Faraday and Joseph Henry - introduce that electromotive force (emf) can be induced in a circuit by changing magnetic field
• Basic and most important law of electromagnetism - Faraday's Law of Induction
• The product of magnetic field and area is called the magnetic analog of electric flux
• Electric Flux - the component of the field normal to the surface
• Unit of magnetic flux : weber
• The current in a coil is called the induced current because it is brought about by changing magnetic field (by moving the magnet)
• If the circuit is open, there would be no current, but there would be an induced EMF
• Induced EMF by changing magnetic field is called electromagnetic induction
• When there is changing of magnetic field through a wire, an emf is induced in a loop
• Lenz's Law - induced emf and induced current are such a direction as to oppose the change that produces them
• unit for Lenz's law is volt
• When a magnet is moved towards the conducting loop, the changing applied magnetic field induces a current
• The current induces an induce magnetic field opposing the applied magnetic field
• positive to negative = south
• negative to positive = north
• Time is inversely proportional to EMF
• Electric generator - converts mechanical energy to electrical energy

  • The flow of electric charges is the output electric current supplied by generator