Foul odour and bad taste of water is removed by treating with__________________?

A. Alum
B. Bleaching powder
C. Activated carbon
D. Copper sulphate

World environment day is observed every year on the 5th of___________________?

A. June
B. December
C. July
D. September

Smoke is produced due to__________________?

A. Insufficient supply of combustion air and insufficient time for combustion
B. Poor quality of fuel and improper mixing of fuel & combustion air
C. Poor design & overloading of furnace
D. All A., B. and C.

Maximum allowable noise exposure limits for a man working for 8 hours a day in a noisy chemical plant is about ______________ decibels?

A. 20
B. 60
C. 90
D. 120

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.

The widest explosive limit is of _____________, thereby making it the most explosive gas?

A. Acetylene
B. Petrol vapor
C. Hydrogen
D. Carbon monoxide

Presence of volatile compounds like gasoline, oil, alcohol, ether etc. in municipal sewers may cause___________________?

A. Explosion
B. Non biodegradable foam
C. Undesirable plant growth
D. Corrosion

Green house effect is accentuated by________________?

A. Deforestation
B. Rapid industrialisation
C. Increased transportation activity
D. All A., B. and C.

. Operating principle of cyclone separator is based on the action of _______________ dust particles?

A. Diffusion of
B. Centrifugal force on
C. Gravitational force on
D. Electrostatic force on

Peroxyacetyl nitrate (PAN), a pollutant is found in the_________________?

A. Automobile exhaust
B. Flue gas of coal based power plant
C. Exhaust of nitric acid plant
D. Exhaust of sulphuric acid plant