(a) estimating the amount of organic matter in sewage watert
(b) working out the efficiency of oil driven automobile engines
(c) measuring the activity of Saccharomyces cerevisae in producing curd on a commercial scale
(d) working out the efficiency of RBCs about their capacity to carry oxygen
[CBSE AIPMT 2012]
Correct Option : (a)
Reason : Decomposition of organic matter by microbial activity depends on oxygen availability in water. The degree of impurity of water due to the organic matter is measured in terms of BOD (Biochemical Oxygen Demand) or BOD is the oxygen in milligrams required for five days in one litre of water at 20°C for the microorganisms to metabolise organic waste.