1. What would happen if all the oxygen present in the environment is converted to ozone?
a) We will have greater protection from UV rays of sun
b) It will become poisonous and kill living forms
c) Ozone is not stable so it will be converted back to oxygen
d) Harmful radiation from the sun will reach the earth and damage many life forms.
2. Which one of the following factors does not lead to soil formation in nature
d) Polythene bags
3. Which of the following processes is not involved in carbon cycle?
b) Burning of fossil fuels
4. The main biological process that returns oxygen yo the atmosphere is
a) Burning of fossil fuels
c) Respiration d) Rainfall
5. Which of the following is not an important factor for growth of plants
a) Nutrient content of soil
b) Distance of water body from the soil
c) Amount of humus present in the soil
d) Depth of soil
6. Soil erosion can be prevented by
a) Raising forests
b) Excessive use of fertilizer
d ) Overgrazing by animals
7 Rainfalls depends upon
a) The underground water table
b) The density pattern of human population in area
c) The number of water bodies in an area
d) The prevailing season in an area
8. One of the following processes is not a step involved in the water cycle operating in nature.
b) Snowfall and rain
9. The factor responsible for depletion of the ozone layer is
a) Excessive use of automobiles
b) Excessive use of man-made compounds containing both fluorine and chlorine c) Excessive formation of industrial units
d) Excessive deforestation
10. Which of the following acids fall on land with rain during lightening?
a) Nitric acid and Nitrous acid
b) Hydrochloric acid and Sulphuric acid
c) Sulphuric acid and Nitrous acid
d) Hydrochloric acid and Nitrous acid