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General Knowledge :: Physics

  1. A small gap is left at the joints of rails in a railway track to

  2. A.

     Avoid the tracks being distorted due to seasonal temperature variation

    B.

     Avoid the heating of tracks to high temperature

    C.

     Control the speed of train

    D.

     Keep the rails equidistant


  3. Pipelines in cold countries often burst in winter, because

  4. A.

     Water freezes and expands in its volume

    B.

     Temperature of ice is less than that of water

    C.

     Pipelines contract in their volume

    D.

     Pipelines expand due to freezing


  5. In severe winter, in cold countries water pipes burst because

  6. A.

     Water expands on freezing

    B.

     Contraction of water pipes

    C.

     High atmospheric pressure

    D.

     Combined effect of all the above three


  7. Railway tracks are banked on curves so that

  8. A.

     Necessary centrifugal force may be obtained from the horizontal component of the weight of the train

    B.

     No frictional force may be produced between the tracks and the wheels of the train

    C.

     Necessary centripetal force may be obtained from the horizontal component of the weight of the train

    D.

     The train may not fall down inwards


  9. The density of the liquid when heated

  10. A.

     Decreases

    B.

     Increases

    C.

     Does not change

    D.

     May increase of decrease depending on pressure


  11. Thermocouple consists of

  12. A.

     Two dissimilar metals

    B.

     Two similar metals

    C.

     Metal and a semiconductor

    D.

     Metal and an insulator


  13. Water has maximum density at

  14. A.

     100°C

    B.

     0°C

    C.

     4°C

    D.

     273°C


  15. When water freezes its density

  16. A.

     Decreases

    B.

     Becomes Zero

    C.

     Remains constant

    D.

     Increases


  17. Which of the following are methods of heat transfer?

  18. A.

     Convection

    B.

     Evaporation

    C.

     Revolution

    D.

     Thermal Expansion


  19. Heat energy is transferred by conduction whenever molecules

  20. A.

     Collide each other

    B.

     Means of photons

    C.

     Particles replaces there places

    D.

     All of the above