Assertion : Railways tracks are laid on small sized wooden sleepers.
Reason : Small sized wooden sleepers are used so that rails exert more pressure on the railway track. Due to which rail does not leave the track

Railway tracks are laid on large sized wooden, iron or cement sleepers. Why?

Assertion : paper pins are made to have pointed end. Reason : Because pointed pins have very small area due to which even for small applied force it exert large pressure on the surface.

Why a small gap is left between the iron rails of railway tracks ?

Give reasons for the following statements: (a) Railway tracks are laid on large sized wooden sleepers. (b) It is difficult to walk on and. (c) Walking bare footed on a pebbled path is painful.

(a) Whi are wide wooden sleepers kept below railway lines? (b) Whi does a balloon not collapse under atmospheric pressure?

Advanced countries are making use of powerful electromagnets to move trains at very high speed. These trains are called maglev trains (abbreviated from magnetic levitation).These trains float on a guideway and do not run on steel rail tracks. Instead of using a engine based on fossil fuels, they make use of magnetic field forces. The magnetized coils are arranged in the guide way which repels the strong magnets placed in the train's under carriage. This helps train move over the guideway, a technic called electro - dynamic suspension. When current passes in the coils of guideway , a typical magnetic field is set up between the undercarriage of train and guideway which pushes and pull the train along the guideway depending on the requirement. The lack of friction and its aerodynamic style allows the train to more at very high speed. (i) The levitation of the train is due to

Advanced countries are making use of powerful electromagnets to move trains at very high speed. These trains are called maglev trains (abbreviated from magnetic levitation).These trains float on a guideway and do not run on steel rail tracks. Instead of using a engine based on fossil fuels, they make use of magnetic field forces. The magnetized coils are arranged in the guide way which repels the strong magnets placed in the train's under carriage. This helps train move over the guideway, a technic called electro - dynamic suspension. When current passes in the coils of guideway , a typical magnetic field is set up between the undercarriage of train and guideway which pushes and pull the train along the guideway depending on the requirement. The lack of friction and its aerodynamic style allows the train to more at very high speed. (3) The force which makes maglev move

Advanced countries are making use of powerful electromagnets to move trains at very high speed. These trains are called maglev trains (abbreviated from magnetic levitation).These trains float on a guideway and do not run on steel rail tracks. Instead of using a engine based on fossil fuels, they make use of magnetic field forces. The magnetized coils are arranged in the guide way which repels the strong magnets placed in the train's under carriage. This helps train move over the guideway, a technic called electro - dynamic suspension. When current passes in the coils of guideway , a typical magnetic field is set up between the undercarriage of train and guideway which pushes and pull the train along the guideway depending on the requirement. The lack of friction and its aerodynamic style allows the train to more at very high speed. (2) The disadvantage of maglev trains is that