Question

Assertion (A): If BOD level of water in a reservoir is less than 5 ppm it is highly polluted.

Reason (R): High biological oxygen demand means low activity of bacteria in water.

Options

• Both A and R are correct and R is the correct explanation of A.

• Both A and R are correct but R is not the correct explanation of A.

• Both A and R are not correct.

• A is not correct but R is correct.

Answer 1

Both A and R are not correct.

Explanation:

Since the amount of oxygen required by bacteria to breakdown the organic matter present in a certain volume of a sample of water, is called BOD i.e., Biochemical Oxygen Demand. If the BOD of the water is < 5 ppm then it is clean but if it increases then the water pollution increases.