Eb-9 Lenz’s Law with Aluminium Ring

Aim

To demonstrate the induced EMF when there is relative motion between a conductor and a magnetic field.

Apparatus

  • Suspended Aluminium Ring
  • Retort stand and Boss head
  • Neodymium Boron Magnet

Lenzs Law Aluminium Ring

Lenz's Law Setup.

Description

Lenz’s law states that a changing magnetic field threading a conductor induces an EMF such that the direction of the current flow is to oppose the flux change. This demonstration illustrates Lenz’s law and by the motion of the ring, the direction of the current flow may be inferred. A strong magnet is slowly brought to pass through the central annulus of a suspended Aluminium ring. On approach the magnet is seen to be repelled illustrating that a like pole is induced in the suspended ring. Alternatively when the magnet is slowly removed the ring is seen to be attracted to the magnet illustrating that a current is flowing such that an opposite pole is being induced.

Video