This set covers the composition and layers of the atmosphere, the global pressure belts and the winds they create. These concepts explain weather and climate patterns worldwide and are a regular source of direct and conceptual questions in UPSC Prelims.
How to practise: read each question and tap the option you think is correct. You will see right away whether you got it, along with a short explanation, and your score is tracked at the bottom of the screen. This set has 15 questions.
Topics covered in this set
- Composition of the atmosphere
- Layers of the atmosphere
- Lapse rate and temperature inversion
- Global pressure belts
- Coriolis force and planetary winds
- Local winds and jet streams
UPSC Geography MCQs with answers and explanations
Q1. Which gas makes up the largest share of dry air by volume?
a) Nitrogen
b) Oxygen
c) Argon
d) Carbon dioxide
Q2. Most weather phenomena such as clouds, rain and storms occur in the:
a) stratosphere
b) troposphere
c) mesosphere
d) thermosphere
Q3. The ozone layer is located mainly in the:
a) troposphere
b) mesosphere
c) stratosphere
d) exosphere
Q4. In the troposphere, temperature normally decreases with height at an average rate of about:
a) 1 °C per 1000 m
b) 3 °C per 100 m
c) 20 °C per 1000 m
d) 6.5 °C per 1000 m
Q5. The ionosphere, which reflects radio waves back to the Earth, lies within the:
a) stratosphere
b) thermosphere
c) troposphere
d) mesosphere
Q6. The 'horse latitudes' correspond to the:
a) equatorial low pressure belt
b) sub-polar low pressure belts
c) subtropical high pressure belts
d) polar high pressure belts
Q7. The Doldrums are associated with which pressure belt?
a) Subtropical high pressure belt
b) Sub-polar low pressure belt
c) Polar high pressure belt
d) Equatorial low pressure belt
Q8. Winds in the Northern Hemisphere are deflected to the right mainly because of:
a) the Coriolis force
b) the pressure gradient force
c) friction with the surface
d) gravity
Q9. The trade winds blow from:
a) sub-polar low pressure belts towards the poles
b) the equatorial low towards the subtropical highs
c) the subtropical high pressure belts towards the equatorial low
d) the polar highs towards the sub-polar lows
Q10. The 'Roaring Forties' are:
a) trade winds blowing near 40 degrees north
b) polar easterlies near the Arctic Circle
c) monsoon winds over the Arabian Sea
d) strong westerly winds in the Southern Hemisphere at about 40 to 50 degrees south
Q11. Which local wind is a warm, dry wind that blows down the leeward slopes of the Alps?
a) Foehn
b) Mistral
c) Bora
d) Harmattan
Q12. Which statement about land and sea breezes is correct?
a) A sea breeze blows at night from sea to land
b) A sea breeze blows during the day from sea to land
c) A land breeze blows during the day from land to sea
d) They are caused mainly by the Coriolis force
Q13. Jet streams are best described as:
a) surface winds that blow only in the tropics
b) cold ocean currents
c) local winds in mountain valleys
d) narrow bands of very fast winds near the tropopause, mostly flowing from west to east
Q14. Isobars are lines on a map joining places of equal:
a) temperature
b) atmospheric pressure
c) rainfall
d) humidity
Q15. Which statement about temperature inversion is correct?
a) Temperature always decreases with height during an inversion
b) It is most common on cloudy and windy nights
c) Temperature increases with height in a layer of air, often on long, clear, calm winter nights
d) It occurs only over the oceans
Quick revision notes
- Dry air is about 78 percent nitrogen, 21 percent oxygen and just under 1 percent argon.
- The layers of the atmosphere from the surface upward are the troposphere, stratosphere, mesosphere, thermosphere and exosphere.
- The normal lapse rate is about 6.5 °C fall in temperature for every 1000 m of height in the troposphere.
- The pressure belts are the equatorial low, subtropical highs, sub-polar lows and polar highs.
- Trade winds, westerlies and polar easterlies are the three main planetary wind systems in each hemisphere.
- The Coriolis force deflects winds to the right in the Northern Hemisphere and is absent at the equator.
Frequently asked questions
Why is the troposphere thicker at the equator than at the poles?
Strong heating at the equator produces powerful rising air currents that carry heat to greater heights. At the poles the surface is cold and convection is weak, so the troposphere is shallower.
What is the role of the Coriolis force in wind direction?
The Coriolis force arises from the Earth's rotation and changes the direction of moving air, not its speed. It is why winds blow around pressure centres instead of straight across isobars.
How do pressure belts shift during the year?
The pressure belts move north and south with the apparent movement of the Sun. They shift northward in the northern summer and southward in the northern winter, which affects seasonal rainfall in many regions.
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