First you will observe that without aluminum disc the rod moves freely with greater speed and does not stop for long time. Whereas, by placing the Aluminum metal disc below it, the rod moves with less swings and gets stops after a while.
This happens because of the eddy current. Now the question arises, what are eddy currents? Eddy currents are the currents created when a conductor experiences changes in the magnetic field. If either the conductor is moving through a steady magnetic field or the magnetic field is changing around a stationary conductor, eddy current is produced because of electromagnetic induction. In our project the second case is applied i.e. the magnetic field is changing around a stationary conductor .In our project,Aluminum disc is the conductor and the magnetic field of the cylindrical magnet continuously changes with the motion of the magnet. As a result electric current is produced.The eddy current generates an opposing magnetic field which resists the rotation or the swing, providing a break force.Thus motion of the magnet stops.
An Eddy current brake is responsible for slowing the speed of the object. The most common application areas of eddy current are as magnetic brakes of trains, roller coasters and air craft.The eddy current brake swill likely to be found in cars as well.The eddy current brakes are used in these vehicles,as they run with the great speed. If the mechanical friction brake is applied the vehicle will suddenly stop causing an accident.In these types of vehicles it is first necessary to slow down the speed before coming to the rest, which is possible through eddy current.
• Eddy current is produced on the basis of the principle of...
(b) Electromagnetic induction,
• Eddy current is produced when ...
(a) There are changes in the magnetic field
(b) Magnetic field remains constant
(c) Cannot tell anything
• Eddy current brakes are used in ...
(a) Air crafts
(c) Roller coaster
(d) All of above