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General Knowledge :: Physics

  1. In a railway track, two rails are joined end to end with a gap in between them because

  2. A.

     Steel can be saved

    B.

     Accidents due to contraction in winter can be avoided

    C.

     Air-gaps are necessary for bearing the weight of running train

    D.

     Accidents due to expansion in summer can be avoided


  3. Air coolers are more suitable for

  4. A.

     Hot and humid climate

    B.

     Hot and dry climate

    C.

     Cool and humid climate

    D.

     Cool and dry climate


  5. We feel cool when we sit near the fan, this is because

  6. A.

     Fan gives cool air.

    B.

     Fan cools surrounding air.

    C.

     Air vapourises the sweat on our body.

    D.

     We feel cool when air touches the body.


  7. When hot-water is sprinkled on a hotter glass tumbler, it breaks because

  8. A.

     Glass suddenly expands

    B.

     Glass suddenly contracts

    C.

     Water evaporates

    D.

     Glass reacts chemically with water


  9. A gap is left between two rails of a railway track to accommodate...... of the metal.

  10. A.

     Areal expansion

    B.

     Volume expansion

    C.

     Linear expansion

    D.

     Apparent expansion


  11. Which of the following is arranged in order of decreasing conductivity?

  12. A.

     Copper, Aluminium, Steel, Silver

    B.

     Aluminium, Silver, Copper, Steel

    C.

     Copper, Silver, Aluminium, Steel

    D.

     Silver, Copper, Aluminium, Steel


  13. Every hot object emits ________

  14. A.

     X–rays

    B.

     Visible light

    C.

     Infrared rays

    D.

     Ultraviolet rays


  15. Which metal is the best conductor of heat?

  16. A.

     Silver

    B.

     Gold

    C.

     Copper

    D.

     All of the above


  17. When hot liquid is poured into a thick glass tumbler, it cracks because glass :

  18. A.

     Is a bad conductor of heat so only inner surface expands

    B.

     Has high temperature coefficient of expansion

    C.

     Has a very low specific heat

    D.

     Has low temperature coefficient of expansion


  19. Mud houses are cooler in summers and warmer in winters as compared to brick houses because

  20. A.

     Mud is a good conductor

    B.

     Mud is a bad conductor

    C.

     Mud is a poor insulator

    D.

     Evaporation of water causes cooling in summers and sunlight coming through holes causes warming in winters