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GS Paper IUPSC Prelims 2003
Health & Medicine
Question No. 259Interactive Test Mode
00:00
+2-0.66

Q259. Which one of the following statements is not correct?

Which one of the following statements is not correct?

Select the correct option below (or cross out options to eliminate)
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Official Answer Key & Detailed Solution

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Official UPSC Answer KeyUPSC Prelims 2003 • Science and Technology

Correct Answer: Option (C) — The velocity of sound in air decreases as the humidity increases.

Concept & Option Breakdown

Standard Reference Verified

Option (c) is incorrect: Humid air contains water vapor (molecular mass ~18 g/mol), which is lighter than dry air (predominantly N2 and O2, average mass ~29 g/mol). Adding humidity decreases the density of air, which increases the velocity of sound. Hence, sound travels faster in humid air, not slower. All other statements are scientifically correct.

Elimination Heuristic & Exam Approach

Water vapor is lighter than dry air (N2/O2). Lower density means faster sound propagation (v ∝ 1/√ρ).

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Question Specifications & Syllabus Mapping

Examination & YearUPSC Civil Services Preliminary Examination 2003 (Q259)
Paper & Marking SchemeGS Paper I • 2 Marks (-0.66 Negative for incorrect response)
Syllabus Subject & TopicScience and Technology → Health & Medicine
Official Answer KeyOption (C) — The velocity of sound in air decreases as the humidity increases.

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More PYQs from Science and Technology (Health & Medicine)

Master the Science and Technology syllabus cluster by practicing these related previous year questions.

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Frequently Asked Questions — UPSC Prelims 2003 Q259

What is the official answer for UPSC Prelims 2003 GS Paper I Question 259 (Science and Technology)?

The official UPSC answer key for this 2003 Science and Technology (Health & Medicine) question is Option (C): "The velocity of sound in air decreases as the humidity increases.". Correct attempts carry 2 Marks with -0.66 Negative penalty for wrong answers.

Which UPSC Prelims syllabus topic does this 2003 question belong to?

This question belongs to GS Paper I under the subject "Science and Technology" and micro-topic "Health & Medicine". You can explore all repeated questions from Health & Medicine in Acme AI's 3D Prelims PYQ Realm or practice 50 full-length and sectional tests in the APT Prelims Test Series.

How can I solve this Health & Medicine UPSC Prelims question using option elimination?

Water vapor is lighter than dry air (N2/O2). Lower density means faster sound propagation (v ∝ 1/√ρ).

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Previous QuestionDiffusion of light in the atmosphere takes place due to:
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