Period of cleaning of slow sand filters is about________________?

Question: Nitrogen oxides (NOx) is not produced in the __________ industry.
[A].

nitric acid making

[B].

nitrogenous fertiliser

[C].

detergent

[D].

any of these

Answer: Option C

Explanation:

No answer description available for this question.

Question: Automobile exhaust is passed through two compartments catalytic converter employing platinum as catalyst for
[A].

conversion of CO into CO2 in the second compartment.

[B].

conversion of NOx into N2 and NH3 in the first compartment.

[C].

oxidation of unburnt hydrocarbon fuel in the second compartment.

[D].

all (a), (b) and (c).

Answer: Option D

Explanation:

No answer description available for this question.

Question: Corrosion in boilers can be prevented by
[A].

deaeration of feed water.

[B].

enhancing pH of feed water by adding alkali.

[C].

feeding sodium sulphite or hydrazine phosphate to the boilers, which combines with oxygen and prevents corrosion.

[D].

all (a), (b) and (c).

Answer: Option D

Explanation:

No answer description available for this question.

Question: Iron & manganese present in the polluted water is removed by
[A].

simple filtration.

[B].

oxidation followed by settling & filtration.

[C].

chemical coagulation.

[D].

chlorination only.

Answer: Option B

Explanation:

No answer description available for this question.