Transformer

• These two coils


  • Wrapped around an iron core
  • Can be easily magnetised
• Primary coil


  Connected to a (AC) Alternating current with high voltage (P.D)
• When the current goes through the primary coil

  1. Creates magnetic fields

  2. Constantly changing its direction
• Magnetic field passes through the iron core


  Passed to the secondary coil
• Current enters the secondary coil


  Changes the Voltage or the P.D
• Iron core


  • Used to increase the magnetic field
  • Can be easily magnetized
• Transformers only work with the AC because we constantly need changes in the magnetic field to induce the P.D
• If there are the same number of coil turns


  The PD will remain the same, assuming no energy is wasted
• If there are more turns in the secondary coil

  The PD will be greater than the current in the primary coil. This is called a step-up transformer.
• If there is a double number of turns


  The P.D. will also be doubled
• Step-down transformers


  Transformers with more number of turns in the primary coil