uses of generator effect

• the generator effect can be used in devices called 'generators' which generate electricity from the rotational movement
• dynamos have a split ring commutator and so produce a direct current
• alternators have slip rings and brushes which causes them to produce an alternating current
• alternators:

  • a coil of wire rotates relative to magnets, which induces a magnetic field in the coil which then induces a potential difference and current in the coil
  • the slip rings and brushes mean the contacts don't swap every half turn
  • this means they produce an alternating potential difference and alternating current
  • as the coil rotates faster, the peaks of the oscillations get larger and more frequent
  • the maximum pd is produced when the coil is horizontal because the most magnetic field lines are being cut, greatest interaction
  • no pd when vertical, because they are parallel
• dynamos:

  • as the coil of wire spins relative to the magnet, a magnetic field and hence a voltage and current is induced in the coil
  • the split ring commutator means that the contacts swap every half turn
  • so the current and potential difference are kept in the same direction, and the induced potential difference doesn't reverse its direction
  • as the coil rotates faster, the peaks of the oscillations get larger and more frequent
• slip rings provide a continuous connection and stop the wires from twisting together