358. Consider the following stages in Sulphur cycle under aerobic oxidation 1. Formation of hydrogen sulphide 2. Formation of sulphates 3. Formation of sulphur 4. Photosynthesis The correct sequence of the stages is:
A. 1, 2,3,4
B. 2,4,3, 1
C. 1, 4,3, 2
D. 4,3,2,1
359. Consider the following staes of Carbon cycle under aerobic conditions: 1. Oxidation of carbonaceous organic matter 2. Release of carbon dioxide 3. Carbon dioxide through photosynthesis gest converted into plant carbohydrates 4. The wastes produced by animals and their dead bodies from cabonaceous organic matter Of these stages, the correct sequence is :
A. 1,2,3,4
B. 2,4,3,,1
C. 1,4,3,2
D. 4,3,2,1
360. Consider the following statements regarding the decomposition of sewage A well oxidised sewage contains.1. Nitrates in excess 2. Sulphates in excess 3. Ammonia in excess 4. Hydrogen sulphide in excess Of these statements :
A. 1 alone is correct
B. 2 1one is correct
C. 1 and 2 are correc
D. 3 and 4 are correct
361. Consider the following statement regarding the decomposition of sewage 1. Pathogens are harmful to man 2. Non-pathogens are useful to man 3. Aeration tanks and contact beds work on oxidation 4. Septic tanks and imhoff tanks work on putrefaction Of these statements
A.. One alone is correct
B.. 1 and 2 are correct
C.. 1 and 3 are correct
D.. 1, 2, 3 and 4 are correct
362. Consider the following statements regarding the characteristics of sewage1. The turbidity of sewage is-directly proportional to the strength of sewage 2. The yellowish, grey or light brown colour indicates the freshness of the sewage 3. Fresh sewage is practically odourless 4. At higher temperature, the dissolved oxygen content (D.0.) of sewage gets reduced Of these statements:
A. 1 and 2 are correct
B. 2 and 3 are correct
C. 3 and 4 are correct
D. All are correct
363. Consider the following statements regarding self purification of river water. 1. In clean conditions in a river stream, the oxygen deficit must be nil. 2. The D.O. content goes on increasing due to decomposition of volatile organic matter. 3. In the process of re-oxygenation, consumption of D.O. due to deoxygenation is counter balanced by the atmospheric supplies of oxygen to the water. 4. If the D.O. content becomes zero, aerobic conditions are replaced by putrefaction conditions. Of these statement:
A. 1 alone is correct
B. 1 and 2 are correct
C. 1, 2 and 3 are correct
D. 1, 3 and 4 are correct
364. Consider the following statements regarding dilution of sewage in sea water 1. The sea water contains 80% of oxygen contained in fresh river stream. 2. The sea water can absorb sewage solids more than the fresh water of a stream. 3. Sewage solids chemically react with the dissolved matters of sea water and thus form sludge banks 4. The sludge banks are free from hydrogen sulphide gas Of these statements:
A. 1 and 3 are correct
B. 2 and 4 are correct
C. 1 and 4 are correct
D. 3 and 4 are correct
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