UPSC CSE Prelims
Question 76
Consider the following :
- Pyroclastic debris
- Ash and dust
- Nitrogen compounds
- Sulphur compounds
How many of the above are products of volcanic eruptions ?
View correct answer and explanation
Correct answer: D
Correct Option: D (All four)
Explanation: Volcanic eruptions can eject pyroclastic fragments, ash and dust, and release gases containing sulphur and nitrogen compounds.
Statement / Pair / Item-wise Analysis:
1. Correct/True - Pyroclastic debris includes tephra and lava fragments.
2. Correct/True - Explosive eruptions emit volcanic ash and dust.
3. Correct/True - Nitrogen-bearing gases/species may occur in volcanic emissions.
4. Correct/True - Sulphur dioxide and hydrogen sulphide are common volcanic gases.
Option-wise Analysis:
A. Incorrect-it counts 1, but items 1, 2, 3, 4 qualify, giving 4.
B. Incorrect-it counts 2, but items 1, 2, 3, 4 qualify, giving 4.
C. Incorrect-it counts 3, but items 1, 2, 3, 4 qualify, giving 4.
D. Correct-exactly 4 of the 4 listed items satisfy the condition.