MCQs on the Mesosphere – World Geography
Q1. The mesosphere is the __ layer of Earth’s atmosphere.
a) Lowest
b) Second lowest
c) Third lowest
d) Highest
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Correct Answer: c) Third lowest
Explanation: The mesosphere is the third lowest layer of Earth’s atmosphere, located above the troposphere and below the thermosphere.
Q2. The temperature in the mesosphere generally:
a) Increases with altitude
b) Decreases with altitude
c) Remains constant with altitude
d) Varies unpredictably with altitude
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Correct Answer: b) Decreases with altitude
Explanation: The temperature in the mesosphere generally decreases with altitude due to the decreasing absorption of solar radiation by the rarefied atmosphere and increasing cooling by CO2 radiative emission.
Q3. The coldest temperatures in Earth’s atmosphere are found in the:
a) Troposphere
b) Stratosphere
c) Mesosphere
d) Thermosphere
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Correct Answer: c) Mesosphere
Explanation: The coldest temperatures in Earth’s atmosphere, about -90° C (-130° F), are found near the top of the mesosphere.
Q4. The primary gases in the mesosphere are:
a) Nitrogen and oxygen
b) Oxygen and carbon dioxide
c) Nitrogen and argon
d) Carbon dioxide and argon
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Correct Answer: a) Nitrogen and oxygen
Explanation: The mesosphere is primarily composed of nitrogen and oxygen, with trace amounts of other gases such as argon, carbon dioxide, and water vapour.
Q5. The mesosphere extends from approximately __ kilometers above Earth’s surface.
a) 8 to 15
b) 15 to 35
c) 35 to 50
d) 50 to 85
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Correct Answer: d) 50 to 85
Explanation: The mesosphere extends from approximately 50 to 85 kilometers (31 to 53 miles) above Earth’s surface, located above the troposphere and below the thermosphere.
Q6. The mesopause is the boundary between which two layers of the atmosphere?
a) Troposphere and stratosphere
b) Stratosphere and mesosphere
c) Mesosphere and thermosphere
d) Thermosphere and exosphere
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Correct Answer: c) Mesosphere and thermosphere
Explanation: The mesopause is the boundary between the mesosphere and the thermosphere, where the temperature stops decreasing with altitude and starts increasing.
Q7. The air density in the mesosphere is:
a) Higher than in the troposphere
b) Lower than in the troposphere
c) The same as in the troposphere
d) Higher than in the stratosphere
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Correct Answer: b) Lower than in the troposphere
Explanation: The air density in the mesosphere is lower than in the troposphere due to the decreasing number of gas molecules at higher altitudes.
Q8. The mesosphere is primarily heated by:
a) Direct sunlight
b) The Earth’s surface
c) The Earth’s core
d) The stratosphere
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Correct Answer: a) Direct sunlight
Explanation: The mesosphere is primarily heated by direct sunlight, as it absorbs solar radiation and re-emits it as infrared radiation.
Q9. The mesosphere is characterized by:
a) Vertical mixing
b) Horizontal mixing
c) No mixing
d) Both vertical and horizontal mixing
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Correct Answer: b) Horizontal mixing
Explanation: The mesosphere is characterized by horizontal mixing, as its resistance to vertical mixing means that it is stratified)
Q10. The mesosphere is important for protecting Earth from:
a) Solar radiation
b) Meteoroids
c) Cosmic rays
d) Earth’s magnetic field
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Correct Answer: b) Meteoroids
Explanation: The mesosphere is important for protecting Earth from meteoroids, as it is the layer of the atmosphere where most meteors burn up upon entering.
Q11. The Noctilucent clouds are found in the:
a) Troposphere
b) Stratosphere
c) Mesosphere
d) Thermosphere
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Correct Answer: c) Mesosphere
Explanation: Noctilucent clouds are found in the mesosphere, at altitudes of about 76 to 85 kilometers (47 to 53 miles). These clouds are visible during twilight and are the highest clouds in Earth’s atmosphere.
Q12. The air pressure in the mesosphere is:
a) Higher than in the troposphere
b) Lower than in the troposphere
c) The same as in the troposphere
d) Higher than in the stratosphere
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Correct Answer: b) Lower than in the troposphere
Explanation: The air pressure in the mesosphere is lower than in the troposphere due to the decreasing number of gas molecules at higher altitudes.
Q13. The mesosphere is primarily composed of which two gases?
a) Nitrogen and oxygen
b) Oxygen and carbon dioxide
c) Nitrogen and argon
d) Carbon dioxide and argon
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Correct Answer: a) Nitrogen and oxygen
Explanation: The mesosphere is primarily composed of nitrogen and oxygen, with trace amounts of other gases such as argon, carbon dioxide, and water vapour.
Q14. The temperature in the mesosphere is primarily influenced by:
a) The Earth’s rotation
b) The Earth’s revolution
c) The Earth’s tilt
d) The absorption of solar ultraviolet radiation
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Correct Answer: d) The absorption of solar ultraviolet radiation
Explanation: The temperature in the mesosphere is primarily influenced by the absorption of solar ultraviolet radiation by the ozone layer.
Q15. The temperature in the mesosphere generally increases with altitude in which layer of the atmosphere?
a) Troposphere
b) Stratosphere
c) Mesosphere
d) Thermosphere
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Correct Answer: b) Stratosphere
Explanation: The temperature in the stratosphere generally increases with altitude due to the absorption of solar ultraviolet radiation by the ozone layer.
Q16. The mesosphere is the coldest region of Earth’s atmosphere because:
a) There are few gas molecules in the mesosphere to absorb the Sun’s radiation
b) The mesosphere is farthest from the Sun
c) The mesosphere is closest to the Earth’s surface
d) The mesosphere is not affected by Earth’s rotation
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Correct Answer: a) There are few gas molecules in the mesosphere to absorb the Sun’s radiation
Explanation: The mesosphere is the coldest region of Earth’s atmosphere because there are few gas molecules in the mesosphere to absorb the Sun’s radiation, and the cooling effect of CO2 radiative emission is more significant.
Q17. The air temperature in the mesosphere ranges from:
a) -2.5 degrees Celsius to -90 degrees Celsius
b) -50 degrees Celsius to -100 degrees Celsius
c) -100 degrees Celsius to -150 degrees Celsius
d) -150 degrees Celsius to -200 degrees Celsius
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Correct Answer: a) -2.5 degrees Celsius to -90 degrees Celsius
Explanation: The air temperature in the mesosphere ranges from -2.5 degrees Celsius to -90 degrees Celsius. However, the mesopause can reach temperatures below -100°C
Q18. The mesosphere is the region of the atmosphere located:
a) Between the troposphere and the stratosphere
b) Between the stratosphere and the thermosphere
c) Between the thermosphere and the exosphere
d) Between the troposphere and the thermosphere
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Correct Answer: b) Between the stratosphere and the thermosphere
Explanation: The mesosphere is the region of the atmosphere located between the stratosphere and the thermosphere, extending from approximately 50 to 85 kilometers (31 to 53 miles) above Earth’s surface.
Q19. The phenomenon of meteors burning up upon entering Earth’s atmosphere primarily occurs in the:
a) Troposphere
b) Stratosphere
c) Mesosphere
d) Thermosphere
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Correct Answer: c) Mesosphere
Explanation: The phenomenon of meteors burning up upon entering Earth’s atmosphere primarily occurs in the mesosphere, as the friction between the meteoroids and the sparse gas molecules in this layer generates heat, causing the meteoroids to burn up.