5. An eclipse of the sun occurs when
a) The moon is between the sun and the earth
b) The sun is between the earth and the moon
c) The earth is between the sun and the moon
d) The earth casts its shadow on the moon
e) None of these
6. The ozone layer protects the earth from rays sent by the sun:
a) Ultraviolet rays
b) Infrared rays
c) Gamma rays
d) radioactive rays
e) None of these
7. The ozone layer is present about 30miles (50km) in atmosphere above earth. The stratum (layer) of atmosphere in which ozone layer lies is called as:
a) Exosphere
b) Mesosphere
c) Stratosphere
d) ionosphere
e) Troposphere
8. Which rocks are formed by the alteration of pre-existing rocks by great heat or pressure
a) Igneous rocks
b) Sedimentary rocks
c) Metamorphic rocks
d) Acid rocks
e) Basic rocks