Page 148 - SCERT Kerala State Syllabus 8th Standard Basic Science Textbooks English Medium Part 1_Neat

Bring the north pole of another magnet close to
the north pole of the magnet in the former
experiment. What do you observe? What if you
bring the south pole at the same end? Write
down your observations in the science diary. Fig. 11.2
As far as magnets are concerned, like poles repel Maglev trains
each other and unlike poles attract each other. You might have been fascinated by the

Place two strong bar magnets between the sight of trains speeding along railway
refills fixed on a piece of thermocol as shown in lines. The noise produced by fast rolling
Figure 11.2. metal wheels on rails is perhaps
annoying. Maglev trains or Magnetic
Why does the second magnet float in air?
Levitation trains are trains without
What poles would the ends C and D be when wheels that move fast over the rails.
the bar magnet floats in air? Note down.

Do you think it is possible to move the magnet
on the top with magnet at the bottom without
causing any friction?
What do you observe when you bring the south
pole of another magnet close to the north pole
of the magnet at the top? And what if we bring
the north pole of the magnet instead? Is frictional
force experienced when the magnet at the top It is the interaction between the
magnetic field created by
moves in both these situations?
electromagnets at the bottom of the
Now can't we explain how Maglev trains move
train and the magnetic field resulting
without wheels and friction? from the arrangement of rails that the
Magnetic Compass train rises a little above and moves
forward fast.
Are you familiar with any instrument which
As the movement is one where there is
makes use of the directional property of magnet?
no contact between the train and rails,
What do you think, the instrument shown in both energy loss due to friction and
Figure 11.3, is used for? noise pollution are minimised

considerably. They are vehicles that
move fast silently and easily with less
wear and tear.
Magnets
Magnets

Electro magnet
Electric power source
Fig. 11.3

Basic Science VIII 147