Water Pollution and Prevention MCQs with Explanations
Practice MCQ Questions
Ques: 1
Which of the following is/are the possible consequence/s of heavy sand mining in riverbeds?
Decreased salinity in the river
Pollution of groundwater
Lowering of the water-table
Select the correct answer using codes given below :
Correct Answer:
(B) 2 and 3 only
The removal of sand from the river bed increases the velocity of the flowing water with the distorted flow-regime eventually eroding the river banks. Sands acts like a sponge which helps in recharging the water table. Its progressive depletion in the river is accompanied by declining water tables in the nearby areas. The sand acts as an efficient filter for various pollutants and thus maintains the quality of water in rivers and another aquatic ecosystem.
Ques: 2
The arsenic contamination of drinking water is highest in–
Correct Answer:
(C) Kolkata
The arsenic contamination of drinking water is highest in Kolkata, West Bengal.
Ques: 3
What is the role of Ultra-violet (UV) radiation in the water purification systems?
It inactivates, kills the harmful microorganisms in water.
It removes all the undesirable odours from the water.
It quickens the sedimentation of solid particles, removes turbidity and improves the clarity of water
Which of the statements given above is/are correct?
Correct Answer:
(A) Only 1
Ultra-violet water purification is the most effective method for disinfecting bacteria from the water. Ultra-violet rays penetrate harmful pathogens in water and destroy illness causing micro-organisms. This is extremely efficient in eliminating their ability to reproduce. UV systems destroy 99.99% of harmful micro-organism without adding chemicals or changing water's taste or odour. Hence, option (a) is the correct answer.
Ques: 4
Which of the following is/are used as a disinfectant of water?
Correct Answer:
(D)
All of the above
Water purification is the process of removing undesirable chemicals, biological contaminants, suspended solids and gases from water. Water filtration can be done in many ways like- through temperature, ultraviolet rays and radioactive ions, oxidation of chemicals using a compound of ozone, Iodine and Chlorine. Chloramine (NH2Cl) and Chlorine dioxide (ClO2) are also used for water purification.
Note: Chlorine is used for the purification of drinking water.
Ques: 5
Which of the following has/have shrunk immensely/ dried up in the recent past due to human activities?
Aral Sea
Black Sea
Lake Baikal
Select the correct answer using the code given below :
Correct Answer:
(A) 1 only
The Aral Sea is a saline lake located in Central Asia that was once the world's 4th largest salt lake. The Aral sea which was once 26,300 miles square in size had decreased in size by 2007 to only 10% of its original area.
Ques: 6
In which year was the Water Pollution Prevention and Control Act enforced?
Correct Answer:
(B) 1974
The Water (Prevention and Control of Pollution) Act was enacted in 1974 to provide for the prevention and control of water pollution and for maintaining or restoring the wholesomeness of water in the country. The Act was amended in 1988.
Note: The Water cess Act was enacted in 1977. But it was enforced in 1978.