Disinfection of water is done to destroy pathogenic bacteria and thus prevent water-borne diseases. Disinfection of water may be done by the use of_________________?
(A) Ozone and iodine
(B) Chlorine or its compounds
(C) Ultraviolet light for irradiation of water
(D) All
Which of the following is not a practical method of low level radioactive waste disposal ?
(A) Dilution with inert material
(B) Discharging to atmosphere through tall stacks after dilution
(C) Disposing off in rivers & oceans
(D) Filling in steel crates and shooting it off out of earth’s gravity
The effect of increase in carbon dioxide level of the atmosphere and its profound effect on our climate is called the ________________?
(A) Catalytic conversion
(B) Green house effect
(C) Global warming
(D) Both
Which of the following is an adsorbent for removal of nitrogen oxides from gas/air ?
(A) Active carbon
(B) Silica gel
(C) Bog iron (iron oxide)
(D) Pulverised limestone
Green house gases blanket/block the infrared radiation from earth’s surface to the atmosphere leading to its progressive warming up. Which of the following gases does not exhibit green house effect ?
(A) CO2
(B) H2
(C) SO3
(D) N2
High noise levels produced during operation of fans and compressors can be reduced by using__________________?
(A) Mufflers (silencers)
(B) Acoustic absorbent
(C) Lagging of noisy duct
(D) None of these
Pick out the wrong statement?
(A) All the nitrogenous fertilisers are not soluble in water
(B) A straight fertiliser contains only one nutrient
(C) Calcium cyanamide is used as weed killer in onion fields
(D) The phosphorous nutrient makes the plant stem stronger and increases its branches
Removal of ______________ results from the disinfection of water?
(A) Turbidity
(B) Odour
(C) Hardness
(D) Bacteria
A standard test for determination of hardness in water is termed as ______________ test?
(A) EDTA
(B) Electometric
(C) Total count
(D) Presumptive
The function of skimming tank in sewage treatment is to remove _____________ substances?
(A) Dissolved solid
(B) Suspended solid
(C) Oil & fatty
(D) Gritty & inorganic