JEE Main · 2019 · 10 Jan 2019 · Shift 1 · Environmental Chemistry

Water filled in two glasses A and B have BOD values of 10 and 20 respectively. The correct statement regarding them is

(A)B is more polluted than A✓ Correct
(B) $A$ is suitable for drinking, whereas $B$ is not
(C)both A and B are suitable for drinking
(D) $A$ is more polluted than $B$

Answer: (A)

Solution

Biochemical oxygen demand measures how much dissolved oxygen microbes consume to break down the organic matter in water, so a higher BOD flags more organic pollution. The sample with BOD

20

therefore carries more pollution than the one with BOD

10

. Safe drinking water sits far below either figure, so the comparison the question wants is simply that the higher-BOD glass is the more polluted one.

JEE Main · 2019 · 10 Jan 2019 · Shift 1 · Single correct option

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