The maximum permissible noise level to which a man working in a chemical plant can be exposed for eight hours per day is about ____________ decibels?
A. 60
B. 90
C. 105
D. 120
Chemical Environmental Engineering
Maximum permissible residual chlorine in treated water should be ____________ mg/litre?
Maximum permissible residual chlorine in treated water should be ____________ mg/litre?
A. 0.001 to 0.01
B. 0.2 to 0.3
C. 2 to 3
D. 5 to 10
Inhalation of silica dust by human being during hand drilling in mica mining, lead & zinc mining, silica refractory manufacture and in foundries causes___________________?
Inhalation of silica dust by human being during hand drilling in mica mining, lead & zinc mining, silica refractory manufacture and in foundries causes___________________?
A. Asphyxiation (suffocation)
B. Shortness of breath
C. Tuberculosis
D. All A., B. and C.
In a sedimentation tank, the detention period for water ranges from _____________ hours?
In a sedimentation tank, the detention period for water ranges from _____________ hours?
A. 2 to 4
B. 8 to 12
C. 16 to 20
D. 24 to 32
Inorganic impurities causing water pollution is ____________________?
Inorganic impurities causing water pollution is ____________________?
A. Fats
B. Carbohydrates
C. Salts of metals
D. Protein
Ringelmann chart is used for the evaluation of _____________ pollution?
Ringelmann chart is used for the evaluation of _____________ pollution?
A. Air
B. Water
C. Noise
D. Radioactive
Which of the following is not a source of ozone emission in the atmosphere?
Which of the following is not a source of ozone emission in the atmosphere?
A. Refrigerators
B. Xerox machines
C. Dermatological photo-therapy equipments
D. High voltage electrical equipments
Photochemical smog is formed from automobile exhaust ________________?
Photochemical smog is formed from automobile exhaust ________________?
A. By reaction of hydrocarbon & nitric oxide in presence of sunlight
B. Appears only on sunny days
C. Is harmful for crops and trees also besides causing eye irritation & asthma
D. All A., B. & C.
The lowest layer of atmosphere is known as the_____________________?
The lowest layer of atmosphere is known as the_____________________?
A. Stratosphere
B. Troposphere
C. Ionosphere
D. None of these
The destruction of water-borne pathogens is termed as disinfection of water. Which of the following is a water disinfectant ?
The destruction of water-borne pathogens is termed as disinfection of water. Which of the following is a water disinfectant ?
A. Chlorine
B. Alkalis
C. Benzene hexachloride
D. Alkyl benzene sulphonate (ABS)