chemical engineering MCQs – Page 393

Practise multiple-choice questions from chemical engineering for competitive examinations and subject revision. Review each marked answer and report any item that may be outdated or unclear.

chemical engineering Mcqs
7841. Which of the following is the most severe air pollutant ?
comments icon0

A. Hydrocarbons

B. SO2

C. NOx

D. CO

7842. Noise level during normal conversation among men is about ______________ decibels?
comments icon0

A. 10

B. 45

C. 115

D. 90

7843. The destruction of water-borne pathogens is termed as disinfection of water. Which of the following is a water disinfectant ?
comments icon0
A. Chlorine

B. Alkyl benzene sulphonate (ABS)

C. Alkalis

D. Benzene hexachloride

7844. Which of the following is the common pollutant emitted from metallurgical smelters, thermal power plant and cement plants ?
comments icon0

A. NOx

B. F

C. Hg

D. SO2
7845. Infective bacteria in water is killed by the _____________ process?
comments icon0

A. Disinfection

B. Sterilisation

C. Aeration

D. None of these

7846. Deaeration of high pressure boiler feed water is done to reduce ___________________?
comments icon0
A. Its dissolved oxygen content

B. Foaming from boilers

C. Caustic embrittlement

D. Its silica content

7847. A shallow pond in which the sewage is retained and biologically treated is called__________________?
comments icon0

A. Lagoon

B. Skimming tank

C. Oxidation

D. Imhoff tank

7848. Which of the following air pollutants is not toxic to vegetation i.e., doesnt cause vegetation damage ?
comments icon0

A. Smog & ozone

B. Carbon monoxide

C. Sulphur dioxide & spray of weed killers

D. Hydrogen fluoride & nitrogen oxides

7849. Suspended solid present in the waste water generated in blast furnace gas cooling and cleaning plant is removed by__________________?
comments icon0

A. Biological oxygen pond

B. Lagoons

C. Filtration

D. Radial settling tank (thickener) using coagulant (lime & ferrous sulphate)
7850. There is a change in ______________ during the phase transition?
comments icon0

A. All a, b & c

B. Volume

C. Pressure

D. Temperature

7851. ____________ substances present in sewage are removed in grit chamber during sewage treatment?
comments icon0

A. Fatty

B. Dissolved

C. Inorganic

D. Organic

7852. Iron & manganese present as pollutant in water cannot be removed by__________________?
comments icon0

A. Oxidation followed by settling & filtration

B. Chlorination

C. Lime soda process or manganese zeolite process

D. Ion exchange process

7853. The type of bacteria which is active in trickling filter during biological treatment of sewage is the _____________ bacteria?
comments icon0
A. Aerobic

B. Anaerobic

C. Parasitic

D. Saprophytic

7854. Presence of a certain minimum quantity of fluorine is desirable in potable water to prevent___________________?
comments icon0

A. Scale formation

B. Corrosion

C. Dental cavities

D. Water-borne disease

7855. Lagoons used for purification of polluted water_______________?
comments icon0

A. Gives an excellent final effluent (with 3 to 4 lagoons arranged in series) having suspended

B. Are large shallow artificial lakes also known as clarification lakes, maturation ponds or

C. All A., B. & C.

D. dation ponds

E. Use micro-organisms/bacteria in presence of dissolved oxygen

F. id < 1 mg/litre and BOD = 3.8 mg/litre

7856. Scale formation in boiler is controlled by____________________?
comments icon0

A. Preheating of feed water

B. Eliminating H2S in feed water

C. Reduction in hardness, silica & alumina in feed water

D. Keeping the pH value of feed water just below 7

7857. Work done in case of free expansion is____________________?
comments icon0

A. Indeterminate

B. None of these

C. Negative

D. Zero
7858. High noise level in a chemical plant can be controlled by the_________________?
comments icon0

A. Path control of noise

B. Protection of operating personnel

C. Suppression of noise at the source itself

D. All A., B. & C.
7859. In sewage treatment, the detention period allowed for oxidation ponds ranges from _____________ weeks?
comments icon0
A. 4 to 5

B. 9 to 10

C. 15 to 20

D. 1 to 2

7860. Hazardous/polluting chemical industries should have an exclusion zone with a green belt and general public access prohibited around it, covering a radius of _____________ metres?
comments icon0

A. 400

B. 4000

C. 1000

D. 100