ROHAN'S SCIENCE FAIR WEBSITE

Principles and Application:

Scientific Principles of Magnetism

Magnets are objects that have magnetic fields around them by which they get attracted or repelled by other similar objects. A magnet has two poles, North and South that create field of force around the magnet called a magnetic field. Like poles repel each other, whereas unlike poles attract each other. These forces of repulsion and attraction are the ones used in a magnetic levitating train to lift it (repulsion), guide it (repulsion), and propel it (attraction and repulsion by changing polarity of electromagnets).

An electromagnet becomes a magnet when an electrical current is passed through a piece of metal to produce a magnetic field. The advantage of an electromagnet over a permanent magnet is that its poles can be flipped (North becomes South and South becomes North) by changing the direction of the current. 

As one can see in the diagrams below, when the train is in a position A, the forces of attraction and repulsion between poles on the train versus poles on the track push the train to position B where the electromagnets on the train flip their poles from North to South and South to North whereby the train gets pushed further.  That is how the train moves ahead.

A magnetic levitating train is a train, unlike conventional trains that runs on its own magnetic track. Due to the train running on magnets, the train can go as fast as 500km/h or 300 mph. The first official public train was operational in Shanghai, China in 2002 running at over 400 kph. It is used to connect the Shanghai airport to neighbouring cities.  In the world, countries like Japan, Germany and France have already started to build a magnetic levitating train system and are showing, slowly good results.

Advantages v. Disadvantages

Advantages:
• Less maintenance (no friction)
• Faster (no friction between steel wheels and track) – only air resistance
• Less noise (no friction between steel wheels and track)
• Environment friendly (no fossil fuel consumption and noise)

Disadvantages:
• Cost
• Existing infrastructure (tracks, stations and connecting roads) cannot be used
• Reliability (needs to be improved)