Eddy current how it develops

 

1) Eddy current is the induce current in bulk metallic pieces of conductor.


Eddy current is generated when magnetic flux linked with the conductor changes.

2)




3) When a metallic plate is used like a pendulum in between a magnetic field.

Eddy current is generated on the metallic plate.



4) This eddy current is opposite to the applied magnetic field.



5) So eddy current makes plate sudden stop.



What happens in electrical instrument:

1) In electrical instruments generation of eddy current heated the metallic plates and energy lose happens.



2) The excess of heating can destroy the machine.



How to avoid eddy current:

1) Eddy currents are avoided when the metallic plate has lots of holes or cutting slots are made there







Applications of Eddy current

 


1) Induction Furnace:

A pollution free & CO2 free furnace is the Induction furnace. Here high frequency alternating current is passed through a coil, which develops eddy currents to the metal inside the coil, this makes high temperature heating of the metallic core and metals get melted.


2) Magnetic brakes in train:

Sometime high speed trains are difficult to stop properly. In this scenario, a very strong electromagnet is used in the train, just above the rails.


When electromagnets are activated, eddy current is induced in the rails, which opposes the motion of the train and finally trains stops.



3) electromagnetic damping:

In some  galvanometer a nonmagnetic metallic core is used. And the coil is wound over this core, when current passes through the coil, it generates an eddy current in metallic core & opposes the motion, due to which the coil quickly attains equilibrium and rest.