Primary and Secondary Coil

Primary and Secondary Coil

Primary and Secondary Coil: Current-carrying cod is called primary coil and the coil in which induced current is generated is called secondary coil. An alternating current flows in the primary coil and this induces a voltage in the secondary coil.

Example with explanation

A transformer needs an alternating current that will generate a shifting magnetic field. A shifting magnetic field also induces a changing voltage in a coil. This creates a magnetic field in the secondary coil. Since the current is alternating, the magnetic field also alternates back and forth. This changing magnetic field induces an alternating EMF in the secondary coil. This is the base of how a transformer works:

  • The primary coil is connected to an AC supply
  • An alternating current passes through a primary coil wrapped around a soft iron core
  • The changing current produces a changing magnetic field
  • This induces an alternating voltage in the secondary coil
  • This induces an alternating current (AC) in the circuit connected to the secondary coil.