UPSC Prelims 2004 Q64: Geography – Atmosphere & Climatology
Which one of the following statements is correct?
- (a) Cirrus clouds are composed of ice crystals
- (b) Cirrus clouds exhibit a flat base and have the appearance of rising domes
- (c) Cumulus clouds are white and thin and form delicate patches and give a fibrous and feathery appearance
- (d) Cumulus clouds are classified as high clouds
Answer: (a) Cirrus clouds are composed of ice crystals
Explanation
Types of clouds
| Statement | Verdict |
|---|---|
| a. Cirrus clouds are composed of ice crystals | True — high, thin, at about 8 to 12 km |
| b. Cirrus have a flat base and rising domes | False: that describes cumulus |
| c. Cumulus are white, thin and fibrous | False: that describes cirrus |
| d. Cumulus are high clouds | False: cumulus are low clouds |
Only statement (a) is correct: cirrus clouds are high, feathery clouds made of ice crystals.
Answer: (a) Cirrus clouds are composed of ice crystals.
Why each option is right or wrong
- (a) CORRECT. Cirrus clouds are made of ice crystals.
- (b) Incorrect. A flat base with rising domes describes cumulus.
- (c) Incorrect. Thin fibrous patches describe cirrus.
- (d) Incorrect. Cumulus are low clouds.
Key point
Cirrus: high, ice, feathery. Cumulus: low, heaped, flat base. Stratus: layered.
Remember
Cirrus clouds are high clouds of ice crystals.
Common mistakes
- Swapping the descriptions of cirrus and cumulus.
- Thinking that cumulus are high clouds.
- Forgetting that cirrus are composed of ice.
Exam tip
Cirrus = curl of hair; cumulus = heap.
Sources
- NCERT Class XI Geography — Fundamentals of Physical Geography — Water in the Atmosphere
- World Meteorological Organization — International Cloud Atlas (cirrus and cumulus)