A. Roentgen
B. Decibel
C. Hertz
D. None of these
A. Aerobic
B. Pathogenic
C. Anaerobic
D. Non-pathogenic
A. Automobile exhaust
B. Forest fire
C. Bacterial action in soil and swamp areas
D. All A., B. and C.
A. Low excess air
B. Very high excess air
C. Gaseous fuel in the furnace
D. Liquid fuel in the furnace
A. Ozone
B. Photochemical smog
C. Sulphur dioxide
D. All A., B. & C.
A. 2 to 4
B. 8 to 12
C. 16 to 20
D. 24 to 32
A. Fading of dyes on textiles
B. Corrosion, tarnishing & soiling of metals
C. Reduced strength of textiles
D. All A., B. and C.