what are eddy currents and its applications???
You can refer to my answer I posted in other question. However you can refer to the applications given by Ankita. Good job Ankita !
https://www.meritnation.com/ask-answer/question/explain-eddy-currents/p.../5534731
Eddy means a whirl or circular motion of something.
Whenever a conductor plate is moved through a magnetic field. There is a change of flux through the conductor area. The free electrons inside the conductor flow in circular loops to create eddy(whirl) of current. The direction of these induced current(eddies) is according to Lenz law. These currents flow in such a direction so as to create their own induced magnetic field which oppose the change of flux through the conductor thereby hindering the motion of conductor.
In the given image, the yellow part is a region of constant magnetic field (into the screen). When we move the loop across this region, since the area affected by the magnetic field changes, the loop senses a changing magnetic field, and a current is induced in the loop in a direction to oppose the change of field through the loop.
In the same way when we move a conductor plate through a region of magnetic field, many current loops in the form of eddies are induced in the plate.
In the given figure, the plate is moved away from the field region, the flux of field through the plate area decreases, so eddy currents are induced in the plate that create their own field in the direction or original field(into the screen). You can find the direction of field using right hand thumb rule. clockwise current generates field into the screen.
Eddy current have advantages and disadvantages :
Disadvantage : They flow of eddy currents cause heating of the conductor.
Advantage : This heating effect is used in induction furnace.
Electromagnetic damping : Eddy currents are also used in frictionless magnetic brakes of trains and also used for levitating bullet trains.