Sound produced by an automobile horn heard at a distance of 1.5 metres corresponds to about __________ decibels. 90 180 120 150 TRUE ANSWER : ? YOUR ANSWER : ?
A gas is termed as non-toxic, if its maximum permissible concentration (TLV) ranges from __________ ppm. 1000 to 2000 3000 to 6000 6000 to 9000 10000 to 100000 TRUE ANSWER : ? YOUR ANSWER : ?
If carbon monoxide content in atmospheric air exceeds __________ ppm, death is bound to occur. 500 3000 (i.e. 0.3%) 1000 50 TRUE ANSWER : ? YOUR ANSWER : ?
Corrosion in boilers can be prevented by Deaeration of feed water All of these Feeding sodium sulphite or hydrazine phosphate to the boilers, which combines with oxygen and prevents corrosion Enhancing pH of feed water by adding alkali TRUE ANSWER : ? YOUR ANSWER : ?
The Killer gas which caused Bhopal gas tragedy in 1984 was Phosgene Carbon monoxide Methyl iso-cynate (MIC) Sulphur dioxide TRUE ANSWER : ? YOUR ANSWER : ?
Which of the following pollutants is absent in the emissions from a fertiliser plant ? NO₂ CO SO₂ & SO₃ NH₃ TRUE ANSWER : ? YOUR ANSWER : ?
Replenishment of dissolved oxygen in water stream polluted with industrial waste occurs by Neither A nor B Natural aeration of water stream Photosynthetic action of algae Both A & B TRUE ANSWER : ? YOUR ANSWER : ?
The ratio of oxygen available to the oxygen required for stabilisation of sewage is called the Oxygen ion concentration Bacterial stability factor Biological oxygen demand (BOD) Relative stability TRUE ANSWER : ? YOUR ANSWER : ?
Photochemical smog is formed from automobile exhaust By reaction of hydrocarbon & nitric oxide in presence of sunlight Appears only on sunny days All of these Is harmful for crops and trees also besides causing eye irritation & asthma TRUE ANSWER : ? YOUR ANSWER : ?
Which of the following is not a source of ozone emission in the atmosphere? High voltage electrical equipments Dermatological photo-therapy equipments Xerox machines Refrigerators TRUE ANSWER : ? YOUR ANSWER : ?