The ratio of oxygen available to the oxygen required for stabilisation of sewage is called the Relative stability Biological oxygen demand (BOD) Oxygen ion concentration Bacterial stability factor TRUE ANSWER : ? YOUR ANSWER : ?
Which of the following is the most active zone of atmosphere in which weathering events like rain, storm & lightning occur? None of these Stratosphere Troposphere Thermosphere TRUE ANSWER : ? YOUR ANSWER : ?
Which of the following acts as a natural source of air pollution? Forest fire Deforestation None of these Volcanic eruption TRUE ANSWER : ? YOUR ANSWER : ?
Reingleman chart is used for the evaluation of __________ pollution. Noise Water Air Radioactive TRUE ANSWER : ? YOUR ANSWER : ?
Which of the following fine dust removal equipments is the most efficient? Scrubber Cyclone separator Electrostatic precipitator Bag filter TRUE ANSWER : ? YOUR ANSWER : ?
A gas is termed as non-toxic, if its maximum permissible concentration (TLV) ranges from __________ ppm. 6000 to 9000 10000 to 100000 3000 to 6000 1000 to 2000 TRUE ANSWER : ? YOUR ANSWER : ?
TLV of lead for public sewer/waste water is about __________ ppm. 25 650 150 1 TRUE ANSWER : ? YOUR ANSWER : ?
Maximum permissible turbidity in potable water is __________ ppm. 1 10 1000 250 TRUE ANSWER : ? YOUR ANSWER : ?
Major sources of noise in furnace operation arises from air inspirators, combustion, side wall vibrations and fluctuation in the process heat load. A 50% increase in fuel firing rate may increase the furnace noise level by about __________ decibels. 30 100 3 70 TRUE ANSWER : ? YOUR ANSWER : ?