The concentration of dissolved oxygen (DO) in cold water can go upto :
02Easy92×since 2004Q1086
Water samples with BOD values of 4 ppm and 18 ppm, respectively are :
03Easy92×since 2004Q1087
The maximum prescribed concentration of
copper in drinking water is :
04Easy92×since 2004Q1088
Biochemical Oxygen Demand (BOD) is the
amount of oxygen required (in ppm) :
05Easy92×since 2004Q1089
The presence of soluble fluoride ion upto
1 ppm concentration in drinking water, is :
06Medium92×since 2004Q1090
Given below are two statements :
Statement I : The value of the parameter "Biochemical Oxygen Demand (BOD)" is important for survival of aquatic life.
Statement II : The optimum value of BOD is 6.5 ppm.
In the light of the above statements, choose the most appropriate answer from the options given below :
07Easy92×since 2004Q1091
Which of the following statement(s) is (are) incorrect reason for eutrophication?
(A) excess usage of fertilisers
(B) excess usage of detergents
(C) dense plant population in water bodies
(D) lack of nutrients in water bodies that prevent plant growth
Choose the most appropriate answer from the options given below :
08Easy92×since 2004Q1092
Which one of the following statements is NOT correct?
09Easy92×since 2004Q1093
The conversion of hydroxyapatite occurs due to presence of F^− ions in water. The correct formula of hydroxyapatite is :
10Medium92×since 2004Q1097
Given below are two statements : One is labelled as Assertion A and the other is labelled as Reason R.
Assertion A : Polluted water may have a value of BOD of the order of 17 ppm.
Reason R : BOD is a measure of oxygen required to oxidise both the bio-degradable an non-biodegradable organic material in water.
In the light of the above statements, choose the most appropriate answer from the options given below.