1. The atmosphere consists of several layers. What is the lowest layer of the atmosphere called?
    1. Exosphere
    2. Stratosphere
    3. Troposphere
    4. Lonosphere

  2. As we go up in the atmosphere
    1. temperature decreases and pressure increases
    2. both temperature and pressure increase
    3. temperature increases and pressure decrease
    4. both temperature and pressure decrease

  3. Which one of the following is the correct sequence of planets in order of increasing distance from the sun?
    1. Mercury, Venus, Earth, Mars
    2. Venus, Mars, Uranus, Mercury
    3. Mercury, Earth, Venus, Mars
    4. Jupiter, Mercury, Venus, Earth

  4. The distance between two stars is messured by the unit of
    1. metre
    2. yard
    3. mile
    4. light year

  5. During photosynthesis, plants need
    1. Oxygen
    2. Nitrogen
    3. Water
    4. Carbon dioxide

  6. 'Heavy water' is used in
    1. making soft drinks
    2. atomic reactors
    3. car battery
    4. hospitals for drinking

  7. The velocity of the sound in vacuum is
    1. greater than in air
    2. same as in air
    3. less than in air
    4. None of these

  8. Black hole is
    1. a big hole in the center of Sun
    2. a galaxy of stars
    3. the eleventh planet in our solar system which was discovered by pioneer space craft
    4. a space of intense gravitational force caused by collapse of a star

  9. The main cause of occurrence of earthquakes is
    1. volcanic eruptions
    2. nuclear explosions
    3. movement in earth strata
    4. storms

  10. Relative humidity of the atmosphere is measured by
    1. Barometer
    2. Fathometer
    3. Spectrograph
    4. Hygrometer