Out of the following, TLV of _______________ is maximum (about 500 ppm)?

Related Mcqs:

Which of the following is not a natural source of air pollution ?

A. Volcanic eruptions and lightening discharges B. Biological decay of vegetable matter C. Photochemical oxidation of organic matter D. None of these...

Which of the following is the most lethal water pollutant ?

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

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

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

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...

In water treatment, alum [Al2(SO4)3] is used for the process of __________________?

A. Filtration B. Coagulation C. Sedimentation D. Disinfection...