Materials required : Wooden base, soft iron cylinder, copper wire, metal ring,
AC source, DC source, switch.
- Take wooden base fix a soft iron cylinder on the wooden base vertically.
- Wind copper wire around the soft iron.
- Now take a metal ring which is slightly greater in radius than the radius of soft iron cylinder and insert it through the soft iron cylinder on the wooden base.
- Connect the ends of the coil to the AC source and switch on the current.
- You may notice that metal ring is levitated on the coil.
- Switch off the current, the ring will jump into the air very dramatically.
- Remove the AC supply and connect a DC supply.
- The metal ring levitates because the net force on it is zero.
- The levitation of metal ring is possible only when the metal ring should behave like a magnet and should change its polarities in the some intervals but in a sense opposite to that of the solenoid.
- When switch is on with DC supply there should be a change in flux linked ring.
- Whenever there is a continuous change of magnetic flux linked with closed coil the current is generated in the coil. It is Faraday’s law.
Precautions : Take care when the metal ring is leviated from the cylinder.