Q. No.Natural ageing of a lake by biological enrichment of its water is called
1. Biomagnification
2. Eutrophication
3. Algal blooms
4. Toxification
Find incorrect match
1. Joint forest management (JFM) – 1980
2. National forest policy – 1988
3. Chipko movement – 1984
4. Noise as air pollutant – 1987
1. Carbon
2. Cl
3. Fe
4. Oxygen
Match the items given in Column I with those in Column II and select the correct option 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 |
| Options: | (a) | (b) | (c) | (d) |
| 1. | (ii) | (i) | (iii) | (iv) |
| 2. | (i) | (iii) | (iv) | (ii) |
| 3. | (iii) | (iv) | (i) | (ii) |
| 4. | (i) | (ii) | (iv) | (iii) |
| 1. | increased population of aquatic food web organisms |
| 2. | an increased production of fish due to biodegradable nutrients |
| 3. | death of fish due to lack of oxygen |
| 4. | drying of the river very soon due to algal bloom |
Biochemical Oxygen Demand (BOD) in river water:
| 1. | remains unchanged when algal bloom occurs |
| 2. | has no relationship with the concentration of oxygen in the water |
| 3. | gives a measure of Salmonella in the water |
| 4. | increases, when sewage gets mixed with river water |
Which one of the following statements is correct?
| 1. | Extensive use of chemical fertilizers may lead to eutrophication of nearby water bodies |
| 2. | Both Azotobacter and Rhizobium in root nodules of plants |
| 3. | Cyanobacteria such as Anabaena and Nostoc are important mobilizers of phosphates and potassium for plant nutrition in the soil |
| 4. | At present it is not possible to grow maize without chemical fertilizers |
Which of the following pairs of gases is mainly responsible for green house effect?
1. Carbon dioxide and methane
2. Ozone and Ammonia
3. Oxygen and Nitrogen
4. Nitrogen and Sulphur dioxide
Polyblend, a fine powder of recycled modified plastic, has proved to be a good material for:
1. making tubes and pipes
2. making plastic sacks
3. use as a fertilizer
4. construction of roads
The following diagram shows the working of an electrostatic precipitator. Identify the correct statement:
| 1. | A negative voltage ionizes the air around the wire that in turn ionizes the particles in the air stream. |
| 2. | They are able to remove about 75% of the particulate matter present in the exhaust from a thermal power plant. |
| 3. | The velocity of air between the plates must be rapid enough to allow electrostatic precipitation of the dust particles. |
| 4. | PM 2.5 dust particles are more easily removed by the electrostatic precipitator than larger sized particulate matter. |
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