What is the working principle of maglev? Explain how it can acquire high speed?
MAGLEV is an acronym of magnetic levitation. The most spectacular applications of this would be maglev trains. The coaches of the train do not slide over steel rails but float on a four inch air cushion above the track using Meissner effect of super conducting magnets.
⦁ The train has a superconducting magnet built into the base of the carriages.
⦁ An aluminium guide way is laid on the ground and carriers electric current.
⦁ The walls of the guide way have a series of horizontal and vertical coils mounted inside the guide way. These coils are made up of normal conductors
⦁ The current flowing through its horizontal coils produce a vertical magnetic field. By Meissner effect the superconducting magnet S expels the vertical magnetic flux. This levitates the train and keeps it afloat the guide way, the horizontal coils are thus called levitating coils.
⦁ On the other hand current passing through the vertical coil produce a horizontal magnetic field which pushes the train forward. Thus the vertical coils are called propelling coils.
⦁ The train is fitted with retractable wheels similar to the wheels of an aircraft. Once the train is levitated in air the wheels are retracted into the body and the train glides forward on the air cushion.
⦁ When the train is to be halted the current through the levitating and propelling coils are switched off. The train descends slowly on to the guide way and runs some distance on it till it stops.
⦁ The utility of such levitation is that in the friction the energy loss is minimized allowing the speed of the train rise up to 581 kmph.