UPSC CSE Prelims
Question 69
Consider the following statements:
- Jet streams occur in the Northern Hemisphere only.
- Only some cyclones develop an eye.
- The temperature inside the eye of a cyclone is nearly 10 °C lesser than that of the surroundings.
View correct answer and explanation
Correct answer: C
Correct Option: C (2 only)
Explanation: Jet streams occur in both hemispheres. A well-defined eye develops in sufficiently organised tropical cyclones, and the eye is typically warmer aloft than the surrounding eyewall.
Statement / Pair / Item-wise Analysis:
1. Incorrect - Strong upper-tropospheric jet streams occur in both Northern and Southern Hemispheres.
2. Correct - Only sufficiently strong, organised tropical cyclones have a clear eye.
3. Incorrect - The eye is a relatively warm-core region, not generally 10 °C cooler than its surroundings.
Option-wise Analysis:
A. Incorrect-includes incorrect item 1 (Strong upper-tropospheric jet streams occur in both Northern and Southern Hemispheres); omits correct item 2 (Only sufficiently strong, organised tropical cyclones have a clear eye).
B. Incorrect-includes incorrect item 3 (The eye is a relatively warm-core region, not generally 10 °C cooler than its surroundings).
C. Correct-includes all and only valid statements/items 2.
D. Incorrect-includes incorrect item 1 (Strong upper-tropospheric jet streams occur in both Northern and Southern Hemispheres); includes incorrect item 3 (The eye is a relatively warm-core region, not generally 10 °C cooler than its surroundings); omits correct item 2 (Only sufficiently strong, organised tropical cyclones have a clear eye).