Electromagnetic induction
Posted in Physics, Electromagnetic machinesElectromagnetic induction describes the use of electromagnetisim to create, or induce a voltage in a circuit.
An EMF is induced when there is a relative movement between the wire in a circuit and a magnet. This means that the either the magnet, the wire or both can be moving - aslong as the wire cuts the magnetic field of the magnet.
The key idea of electromagnetic induction, discovered by Michael Faraday in 1831, is that a steady flow of flux around a wire does not itself induce an EMF but rather a change in flux is what induces an EMF. Movement of the wire or magnet causes a change in flux which is why it causes an induced EMF
In essence:
Faraday went on to disover the law of induction (or Faraday's law of induction). This describes the relationship between the rate of change in flux, the EMF produced and the number of turns in the wire of the circuit being induced. This can be written like so:
Increasing the induced current
The induced current can be increased in a number of ways:
- Increasing the turns in the wire of the circuit
- Increasing the speed of the movement between the wire and the magnetic field (i.e. increasing the rate of change of flux)
- Making the magnetic field stronger
- Increasing the area of the coil