Engineering Questions with Answers - Multiple Choice Questions

# Environmental Science MCQ – Atmosphere

1 - Question

At what concentration (in ppm), is nitrogen present in the atmosphere?
a) 780,840
b) 390,420
c) 78,084
d) 900,000

Explanation: Nitrogen constitutes 78% of the atmosphere. So 78% of one million = 780,840 ppm – is the concentration of nitrogen gas in the atmosphere.

2 - Question

In the lower layers of atmosphere, what range of wavelengths of light is predominant?
a) Less than 100 nm
b) Greater than 300 nm
c) Between 100-300 nm
d) All wavelengths are equally present

Explanation: In the lower layers of atmosphere, light of wavelengths greater than 300nm are present and it is because of this reason, there is generally no ozone formation at the ground level.

3 - Question

What does the ratio of the mass of water vapour to mass of air indicate?
a) Absolute humidity
b) Specific humidity
c) Relative humidity
d) Approximate humidity

Explanation: Specific humidity is the mass of water vapour per unit mass of air mixture.

4 - Question

What is the region of mild and irregular wind in the equatorial region known as?
b) Westerlies
c) Doldrums
d) Easterlies

Explanation: Doldrums are the irregular winds and their exact location is hard to analyse. Ships in the region of doldrums might restrict its movement due to a lack of proper wind.

5 - Question

“Roaring forties” is the term used to describe which of the following winds?
a) East-to-west air winds in the southern hemisphere
b) West-to east air winds in the northern hemisphere
c) East-to-west air winds in the northern hemisphere
d) West-to-east air winds in the southern hemisphere

Explanation: Roaring forties found in the southern hemisphere are strong westerly winds caused by air displaced from the equator to the South Pole and aid yachtsmen in on competitions and voyages.

6 - Question

Match the following.

```A. Hurricane               1.Indian Ocean and South Pacific
B. Typhoon                 2.Low level air circulation
C. Cyclone                 3.Northeastern Pacific and Atlantic
D. Tropical Cyclone        4.Northwestern Pacific```

a) A-1; B-3; C-2; D-4
b) A-3; B-4; C-1; D-2
c) A-2; B-3; C-4; D-1
d) A-3; B-2; C-1; D-4

Explanation: Hurricane, typhoon, cyclone are all used to categorise the same type of storm but differ based on their locations across the world. Tropical cyclone is a low level closed air circulation which is classified as a hurricane/typhoon/cyclone if wind speed exceeds 120km/hr.

7 - Question

Which of the following statements is true?
a) Troposphere is equally thick across different parts of the world
b) Troposphere contains the ozone layer
c) Troposphere is thinner at the equator than at the poles
d) Troposphere is thicker at the equator than at the poles

Explanation: Troposphere is nearly 16-17km thick at the equator and thins down to approximately 8km at the poles.

8 - Question

The temperature decreases with altitude in the stratosphere layer.
a) True
b) False

Explanation: Temperature slightly increases with altitude in the stratosphere due to absorption of UV radiations from the sun, by the ozone layer present in the stratosphere.

9 - Question

Which of the following indicates the correct order of the principal layers of the earth’s atmosphere from top to bottom?
a) Troposphere – Stratosphere – Mesosphere – Thermosphere – Exosphere
b) Thermosphere – Stratosphere – Troposphere – Mesosphere – Exosphere
c) Exosphere – Thermosphere – Mesosphere – Stratosphere – Troposphere
d) Exosphere – Mesosphere – Thermosphere – Stratosphere – Troposphere

Explanation: Exosphere is the outermost layer of the atmosphere followed by mesosphere, thermosphere, stratosphere and troposphere.

10 - Question

Which layer of the atmosphere is responsible for aurora formation?
a) Ozone layer
b) Stratosphere
c) Exosphere
d) Ionosphere

Explanation: Ionosphere is a secondary layer of the atmosphere which extends through mesosphere, thermosphere and exosphere during day time and is responsible for aurora – natural light display in the sky in high altitude region.

11 - Question

Which of the following mentioned layers is NOT a homosphere?
a) Exosphere
b) Troposphere
c) Ionosphere
d) Mesosphere

Explanation: Homospheric layers of atmosphere include layers where chemical composition is independent of molecular weight of gases due to mixing by turbulence. Hence the lower layers such as troposphere, ionosphere and mesosphere are homospheres.

12 - Question

Turbopause is highest layer of the homosphere.
a) True
b) False

Explanation: Turbopause marks the height at which homogenous layer, the homosphere ends. Below the turbopause, turbulent mixing of air dominates.

13 - Question

The planetary boundary layer belongs to which of the following atmospheric layers?
a) Exosphere
b) Ionosphere
c) Stratosphere
d) None of the mentioned

Explanation: The planetary boundary layer is the lowermost level of the atmosphere and it belongs to the troposphere.

14 - Question

What is the atmospheric pressure at sea level?
a) 101325 Pa
b) 14.696 psi
c) 760 Torr
d) All of the mentioned

Explanation: As per International Standard Atmosphere, at sea level atmospheric pressure is equal to 101325 Pa which is equal to 14.696 psi and 760 Torr.

15 - Question

By international convention, which line marks the outermost boundary of the Earth’s atmosphere?
a) Space line
b) Boundary line
c) Karman line
d) Astronaut line