Water and its importance Worksheet-2

Water and its importance Worksheet-2

Multiple -Choice Question:

11. How the biological oxygen demand gets affected with the increased presence of organic matter in water?

(a) the oxygen demand decreases

(b) the oxygen demand increases

(c) the oxygen demand remains unchanged

(d) None of these

12. The presence of high coli form (the organisms which are found in the colon i.e. small intestine) counts in water indicate:

(a) phosphorus contamination

(b) decreased biological oxygen demand

(c) contamination by human wastes

(d) none of these

13. Which human activities need the most water?

(a) Personal hygiene                       (b) Cooking

(c) Irrigation                                     (d) Drinking

14. Which of the following is a prime health risk associated with greater penetration of UV radiation through the atmosphere due to depletion of stratospheric ozone? 

(a) Neurological disorder                (b) Increased liver cancer

(c) Increased skin cancer                (d) Damage to digestive system

15. Acid rain is formed due to these gases:

(a) sulphur dioxide and nitrous oxide

(b) oxygen and nitrogen

(c) methane and ozone

(d) methane and sulphur dioxide

16. A major in-stream use of water is for:

(a) dissolving industrial wastes      (b) producing hydroelectric power

(c) agricultural irrigation                (d) none of these

17. Which of the following is not a consequence of global warming?

(a) worsening health effects       

(b) increased storm frequency and intensity        

(c) rising sea level        

(d) increased agricultural productivity worldwide

18. The concentration of which gas is highest in our environment?

(a) Nitrogen                                     (b) Oxygen         

(c) Carbon dioxide                           (d) Hydrogen

19. What is the harm caused by the depletion of Earth's ozone layer?

(a) Increased amount of Ultra violet radiation will reach earth's surface

(b) Sea levels will rise as the polar ice caps will gradually melt

(c) The oxygen content of the atmosphere will decrease

(d) The average temperature of earth's surface will increase gradually

20. What is a green job?

(a) A job in the environmental sector

(b) A job where we wear green clothes

(c) A career for novices in their field

(d) All of these

Answer Key:

11. (b)
12. (c)
13. (c)
14. (c)
15. (a)
16. (b)
17. (d)
18. (b)
19. (a)
20. (a)