Nitrates and phosphates flowing from agricultural farms into water bodies are a significant cause of :
What will happen if fresh water lake gets contaminated by addition of polluted water with high BOD?
Match List-I with List-II.
List - I | List - II | ||
---|---|---|---|
(A) | Deforestation | (I) | Responsible for heating of Earth's surface and atmosphere |
(B) | Reforestation | (II) | Conversion of forested areas to non-forested areas |
(C) | Green-house effect | (III) | Natural ageing of lake by nutrient enrichment of its water |
(D) | Eutrophication | (IV) | Process of restoring a forest that once existed but was removed |
Choose the correct answer from the options given below :
Select the correct statements regarding dissolved Oxygen and Biochemical Oxygen Demand.
(A) BOD is inversely related to dissolved oxygen.
(B) Low dissolved oxygen and high BOD lead to loss of aquatic life.
(C) High BOD leads to high dissolved oxygen.
(D) Both BOD and dissolved oxygen are indicator of health of a water body.
(E) Both BOD and dissolved oxygen are affected by amount of organic matter in the water body.
Choose the most appropriate answer from the options given below :
The thickness of ozone in a column of air in the atmosphere is measured in terms of :
Which of the following statements is correct?
Given below are two statements:
Statement I: Electrostatic precipitator is most widely used in thermal power plant.
Statement II : Electrostatic precipitator in thermal power plant removes ionising radiations.
In the light of the above statements, choose the most appropriate answer from the options given below:
Why CNG is considered better fuel than diesel?
(a) It can not be adulterated.
(b) It takes less time to fill the fuel tank
(c) It burns more efficiently.
(d) It is cheaper.
(e) It is less inflammable.
Choose the most appropriate answer from the options given below :
The device which can remove particulate matter present in the exhaust from a thermal power plant is:
The entire fleet of buses in Delhi were converted to CNG from diesel. In reference to this, which one of the following statements is false?
Given below are two statements:
Statement I : In a scrubber the exhaust from the thermal plant is passed through the electric wires to charge the dust particles.
Statement II : Particulate matter (PM 2.5) cannot be removed by scrubber but can be removed by an electrostatic precipitator.
In the light of the above statements, choose the most appropriate answer from the options given below:
Column I | Column II |
---|---|
(A) Eutrophication | (i) UV-B radiation |
(B) Sanitary landfill | (ii) Deforestation |
(C) Snow blindness | (iii) Nutrient enrichment |
(D) Jhum cultivation | (iv) Waste disposal |
(i) Lots of urea and phosphate fertilizer were used in the crops in the vicinity
(ii) the area was sprayed with DDT by an aircraft
(iii) The lake water turned green and stinky
(iv) Phytoplankton populations in the lake declined initially thereby greatly reducing photosynthesis
Which two of the above were the main causes of fish mortality in the lake?