The density of the gases (present in air) decreases with increasing altitude to such an extent, that about 70% of the mass of atmospheric air is found in the lower 5 km. of the atmosphere. This lower region of atmosphere is called the_________________?

Related Mcqs:

1. Very small amount of air pollutants are present in stratosphere also; though most of the atmospheric pollutants are present in the troposphere. Which of the following atmospheric pollutants does not cause the ozone layer depletion in atmosphere at tremendous rate ?

   A. CO
   B. SO2
   C. NOx
   D. CFC (chloro fluoro carbons)

2. There are five concentric layers within the atmosphere which is differentiated on the basis of temperature. The atmospheric layer which lies close to the earth’s surface in which human being along with other organisms live is called troposphere. The rate at which air temperature in the troposphere gradually decreases with height is about _____________ °C/km?

   A. 0.05
   B. 1
   C. 6.5
   D. 15

3. Atmospheric pollution caused by the exhaust gas of supersonic transport air-crafts is mostly in the atmospheric region called________________?

   A. Thermosphere
   B. Stratosphere
   C. Troposphere
   D. Mesosphere

4. Oceans act as sinks for atmospheric gases including carbon dioxide whose concentration in the atmosphere is increased by the_______________?

   A. Forestation
   B. Rain
   C. Green house effect
   D. Vegetation

5. Green house gases blanket/block the infrared radiation from earth’s surface to the atmosphere leading to its progressive warming up. Which of the following gases does not exhibit green house effect ?

   A. CO2
   B. H2
   C. SO3
   D. N2

6. The earth’s atmosphere is an envelope of gases present upto a height of about ______________ kms?

   A. 10
   B. 200
   C. 1000
   D. 2000

7. ‘Safe limit’ called Threshold Limit Value (TLV) of carbon monoxide in atmospheric air is < 50 ppm. The main source of carbon monoxide pollutant in air is the____________________?

   A. Industrial chimney exhaust
   B. Automobiles exhaust
   C. Photochemical reaction in polluted atmosphere
   D. Burning of domestic fuel

8. Aerosols present in atmospheric air may be__________________?

   A. Positively charged
   B. Negatively charged
   C. Neutral
   D. Combination of all A., B. & C.

9. Most of the atmospheric air pollutants are present in large quantity in__________________?

   A. Stratosphere
   B. Thermosphere
   C. Troposphere
   D. Mesosphere

10. Heat capacity of air can be approximately expressed as, Cp = 26.693 + 7.365 x10-3 T, where, Cp is in J/mole.K and T is in K. The heat given off by 1 mole of air when cooled at atmospheric pressure from 500°C to – 100°C is ____________________?

    A. 10.73 kJ
    B. 16.15 kJ
    C. 18.11 kJ
    D. 18.33 kJ