MCQs on the Atmosphere – Geography
Q1. The Earth’s atmosphere is primarily composed of:
a) Nitrogen and oxygen
b) Nitrogen and carbon dioxide
c) Oxygen and carbon dioxide
d) Oxygen and argon
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Correct Answer: a) Nitrogen and oxygen
Explanation: The Earth’s atmosphere is primarily composed of nitrogen (78%) and oxygen (21%), with trace amounts of other gases such as argon, carbon dioxide, and water vapour.
Q2. Which layer of the atmosphere is closest to the Earth’s surface?
a) Troposphere
b) Stratosphere
c) Mesosphere
d) Thermosphere
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Correct Answer: a) Troposphere
Explanation: The troposphere is the lowest layer of the Earth’s atmosphere, extending from the Earth’s surface to an altitude of about 8 to 15 kilometers.
Q3. Which layer of the atmosphere contains the ozone layer?
a) Troposphere
b) Stratosphere
c) Mesosphere
d) Thermosphere
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Correct Answer: b) Stratosphere
Explanation: The ozone layer is located in the stratosphere, which is the second layer of the Earth’s atmosphere, above the troposphere.
Q4. The Earth’s atmosphere is divided into how many main layers?
a) 2
b) 3
c) 4
d) 5
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Correct Answer: c) 5
Explanation: The Earth’s atmosphere is divided into four main layers: the troposphere, stratosphere, mesosphere, thermosphere and exosphere.
Q5. The temperature in the stratosphere 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: a) Increases with altitude
Explanation: The temperature in the stratosphere generally increases with altitude due to the absorption of ultraviolet radiation by the ozone layer.
Q6. 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, reaching the coldest temperatures in the Earth’s atmosphere.
Q7. The ionosphere is a region of the atmosphere that is:
a) Located within the troposphere
b) Located within the stratosphere
c) Located within the mesosphere
d) Located within the thermosphere
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Correct Answer: d) Located within the thermosphere
Explanation: The ionosphere is a region of the atmosphere that is located within the thermosphere, where the atmosphere is ionized by solar radiation.
Q8. The greenhouse effect is caused by:
a) The reflection of sunlight by the Earth’s surface
b) The absorption of sunlight by the Earth’s surface
c) The trapping of heat by gases in the Earth’s atmosphere
d) The release of heat by gases in the Earth’s atmosphere
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Correct Answer: c) The trapping of heat by gases in the Earth’s atmosphere
Explanation: The greenhouse effect is caused by the trapping of heat by gases in the Earth’s atmosphere, such as carbon dioxide, methane, and water vapor, which absorb and re-emit infrared radiation.
Q9. The main source of oxygen in the Earth’s atmosphere is:
a) Volcanic eruptions
b) Photosynthesis
c) The decay of organic matter
d) The burning of fossil fuels
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Correct Answer: b) Photosynthesis
Explanation: The main source of oxygen in the Earth’s atmosphere is photosynthesis, the process by which plants, algae, and some bacteria convert sunlight, carbon dioxide, and water into oxygen and glucose.
Q10. The main source of carbon dioxide in the Earth’s atmosphere is:
a) Volcanic eruptions
b) Photosynthesis
c) The decay of organic matter
d) The burning of fossil fuels
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Correct Answer: d) The burning of fossil fuels
Explanation: The main source of carbon dioxide in the Earth’s atmosphere is the burning of fossil fuels, such as coal, oil, and natural gas, which releases carbon dioxide as a byproduct.
Q11. The tropopause 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: a) Troposphere and stratosphere
Explanation: The tropopause is the boundary between the troposphere and the stratosphere, where the temperature stops decreasing with altitude and starts increasing.
Q12. The stratopause 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: b) Stratosphere and mesosphere
Explanation: The stratopause is the boundary between the stratosphere and the mesosphere, where the temperature stops increasing with altitude and starts decreasing
Q13. 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.
Q14. The Earth’s atmosphere is thickest at:
a) The equator
b) The poles
c) Mid-latitudes
d) The tropopause
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Correct Answer: a) The equator
Explanation: The Earth’s atmosphere is thickest at the equator due to the centrifugal force caused by Earth’s rotation, which causes the atmosphere to bulge outward at the equator.
Q15. The ozone layer is primarily located in which layer of the atmosphere?
a) Troposphere
b) Stratosphere
c) Mesosphere
d) Thermosphere
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Correct Answer: b) Stratosphere
Explanation: The ozone layer is primarily located in the stratosphere, where it absorbs and protects the Earth from harmful ultraviolet (UV) radiation from the Sun.
Q16. The Coriolis Effect is caused by:
a) Earth’s rotation
b) Earth’s revolution
c) Earth’s tilt
d) Earth’s magnetic field
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Correct Answer: a) Earth’s rotation
Explanation: The Coriolis Effect is caused by Earth’s rotation, which results in the apparent deflection of objects moving in a straight path when observed from a rotating frame of reference.
Q17. The Coriolis Effect influences which of the following?
a) Ocean currents
b) Wind patterns
c) Both ocean currents and wind patterns
d) Neither ocean currents nor wind patterns
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Correct Answer: c) Both ocean currents and wind patterns
Explanation: The Coriolis Effect influences both ocean currents and wind patterns due to the Earth’s rotation.
Q18. The greenhouse effect is primarily caused by the presence of which gas in the Earth’s atmosphere?
a) Nitrogen
b) Oxygen
c) Carbon dioxide
d) Argon
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Correct Answer: c) Carbon dioxide
Explanation: The greenhouse effect is primarily caused by the presence of carbon dioxide in the Earth’s atmosphere. Carbon dioxide, along with other greenhouse gases such as methane and water vapor, absorbs and re-emits infrared radiation, trapping heat in the atmosphere and leading to global warming and climate change.
Q19. The Earth’s atmosphere exerts pressure on the Earth’s surface due to:
a) The weight of the atmosphere
b) The Earth’s magnetic field
c) The Earth’s rotation
d) The Earth’s axial tilt
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Correct Answer: a) The weight of the atmosphere
Explanation: The Earth’s atmosphere exerts pressure on the Earth’s surface due to the weight of the atmosphere, which is the result of the force of gravity acting on the mass of the atmospheric gases.
Q20. The jet stream is a fast-moving current of air found in which layer of the atmosphere?
a) Troposphere
b) Stratosphere
c) Mesosphere
d) Thermosphere
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Correct Answer: a) Troposphere
Explanation: The jet stream is a fast-moving current of air found in the troposphere, the lowest layer of the Earth’s atmosphere. Jet streams are typically located near the boundaries between large air masses with significant temperature differences and play a crucial role in determining weather patterns.