UV rays are highly injurious to living organisms as:
1. they are part of invisible electromagnetic spectrum
2. they cannot be stopped by atmospheric gases
3. they are preferentially absorbed by DNA and proteins
4. they cause dissociation of atmospheric oxygen
The thickness of ozone layer is measured in :
1. Centimorgan (cM)
2. Dobson unit
3. Roentgens
4. Lux
CFC have a continuing effect on ozone layer as:
1. | the Cl atoms formed by them only act as catalysts in reactions causing degradation of ozone |
2. | the Cl atoms formed by them are used up in reactions causing degradation of ozone |
3. | they are being produced in increasing amounts all over the world |
4. | they are efficiently absorbed by the atmospheric water vapours |
Ozone hole is:
1. | a partial gap in the stratospheric ozone layer over Antarctica |
2. | a partial gap in the stratospheric ozone layer over Arctic |
3. | thinning of ozone layers over polar regions |
4. | excessive buildup of lower troposphere ozone |
Which of the following is implicated in the causation of skin cancers and snow-blindness cataracts in humans?
1. | UV – A | 2. | UV - B |
3. | UV - C | 4. | None of the above |
The normal greenhouse effect is necessary for survival of life on Earth as it has raised the temperature of Earth’s surface by:
1. | - 18°C | 2. | 15°C |
3. | 33°C | 4. | 50°C |
The correct descending order of the relative contribution of various greenhouse gases to total global warming is:
1. carbon dioxide; methane; nitrous oxide; CFCs
2. carbon dioxide; CFCs; methane; nitrous oxide
3. carbon dioxide; CFCs; nitrous oxide; methane
4. carbon dioxide; methane; CFCs; nitrous oxide
An abnormal warming of surface ocean waters in the eastern tropical Pacific is termed as:
1. | El Nino | 2. | La Nina |
3. | ENSO | 4. | Ocean hazard |
The three-mile island is famous as:
1. | it hosted the Kyoto protocol |
2. | it was the site of a large oil spill |
3. | it was a site of a nuclear accident |
4. | it hosted the Earth summit |
Burying the radioactive wastes is not acceptable to many people as:
1. there is a risk of groundwater contamination
2. it may explode
3. it will harm the buried dead bodies
4. it may get accumulated in vegetation