Magnetic levitation (maglev), take place when the magnetic interaction is strong enough to balance the force of gravity. The like poles of two magnets repel one another, and if the magnets are placed vertically and the strength of the repulsion is the same as the strength of gravity, the net force is zero. The magnet on top appears to float in air, or levitate.
Generally it takes a strong magnet on the bottom and a light weight magnet on top to accomplish this task. But if the magnets are powerful, even massive objects such as a train can be levitated. Magnets that can be quickly adjusted, such as electromagnets, are typically used in maglevs.
Magnetic fields not only levitate but also propel maglev trains. Propulsion occurs because the magnetic field changes around the moving train, attracting the train to the area ahead or repelling it from the area behind (or both).
Advantages of Magnetically Levitated Trains (Maglevs)
One of the key advantages of Maglevs is the elimination of friction that conventional trains encounter as their wheels turn along the railroad tracks. Friction is a force that occurs when two objects rub or slide against one another, and the force tends to oppose motion; the force of attraction is necessary to a train’s movement because otherwise the wheels wouldn’t grip the track but unintentional friction caused by rubbing among the axles, wheels, and track must be overcome by expending more fuel.
Another advantage of Maglevs is that they can move very fast, possibly in a way that would be cheaper than other forms of rapid transportation. Since Maglev trains don’t use wheels or axles or other moving parts, they are not limited by mechanical or structural restrictions created by such components.
The maintenance costs of Maglev trains should also be lower than those of conventional trains, since the use of fewer moving parts, most of which don’t rub together, means less wear and less replacement.
The Limitations of Maglevs
In most designs, the guide way i.e. the path that provides the magnetic fields to levitate and propel the train is costly. Compared to conventional trains, in which the track is fairly cheap but the locomotives and cars are costly, maglev trains require a large initial investment to build the pathway along which the train moves. The cost limits the construction of Maglevs.
Also Read: Uses of Static Electricity
