Which of the following is the most lethal water pollutant ?

A. Phenol and cyanide
B. Chlorine
C. Alkalis
D. Suspended solids

The detrimental effect on organism and water quality with temperature rise of aquatic system is the reduction of _____________ of water?

A. Dissolved oxygen content
B. Biological oxygen demand
C. Vapor pressure
D. All A., B. and C.

Which of the following industries discharge mercury as a pollutant ?

A. Chloro-alkali industry
B. Tanneries
C. Beverage plant
D. Phosphoric acid plant

The Killer gas which caused Bhopal gas tragedy in 1984 was________________?

A. Phosgene
B. Methyl isocyanate (MIC)
C. Carbon monoxide
D. Sulphur dioxide

Permissible safe limit (TLV) of _____________ toxic gas is 100-1000 parts per million (ppm)?

A. Highly
B. Moderately
C. Extremely
D. Very extremely

The common pollutant generated in chlor-alkali industry and battery manufacture is ___________________?

A. Mercury
B. Brine
C. Phosphate
D. None of these

Deaeration of high pressure boiler feed water is done to reduce ___________________?

A. Foaming from boilers
B. Its dissolved oxygen content
C. Its silica content
D. Caustic embrittlement

Which of the following radioactive wastes emits all α, β & γ rays and hence is the most hazardous of all radioactive emitters ?

A. I-131
B. Sr-90
C. Au-198
D. Ra-226

Beyond what concentration of H2S in air, acute danger to human life exists ?

A. 50 ppm
B. 100 ppm
C. 300 ppm
D. 700 ppm

Methyl isocyanate (MIC) gas (TLV <1 ppm), which caused Bhopal gas tragedy in 1984 falls under the category of ______________ toxic gas?

A. Moderately
B. Highly
C. Extremely
D. Very extremely