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.

Assertion (A) : If BOD level of water in a reservoir is less than 5 pp

1.	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.
Answer» 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. Solution :To breakdown the ORGANIC matter present in a certain volume of a sample of water AMOUNT of oxygen and required by bacterica known as BIOCHEMICAL Oxygen Demand (BOD). If BOD level is less than 5 ppm. water is almost pure. High biological oxygen demand MEANS high activity of bacteria in water.