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GS Paper IUPSC Prelims 1997
Health & Medicine
Question No. 361Interactive Test Mode
00:00
+2-0.66

Q361. Which one of the following has the highest fuel value?

Which one of the following has the highest fuel value?

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 1997 • Science and Technology

Correct Answer: Option (A) — Hydrogen

Concept & Option Breakdown

Standard Reference Verified

Hydrogen has the highest calorific / fuel value among all known chemical fuels, yielding approximately $140\text{ to }150\text{ MJ/kg}$, compared to natural gas ($50–55\text{ MJ/kg}$), gasoline ($44–47\text{ MJ/kg}$), and charcoal (~$30\text{ MJ/kg}$).

Elimination Heuristic & Exam Approach

Hydrogen has the highest energy per unit mass of any chemical fuel due to its low molecular weight and high heat of combustion.

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Question Specifications & Syllabus Mapping

Examination & YearUPSC Civil Services Preliminary Examination 1997 (Q361)
Paper & Marking SchemeGS Paper I • 2 Marks (-0.66 Negative for incorrect response)
Syllabus Subject & TopicScience and Technology → Health & Medicine
Official Answer KeyOption (A) — Hydrogen

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Frequently Asked Questions — UPSC Prelims 1997 Q361

What is the official answer for UPSC Prelims 1997 GS Paper I Question 361 (Science and Technology)?

The official UPSC answer key for this 1997 Science and Technology (Health & Medicine) question is Option (A): "Hydrogen". Correct attempts carry 2 Marks with -0.66 Negative penalty for wrong answers.

Which UPSC Prelims syllabus topic does this 1997 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?

Hydrogen has the highest energy per unit mass of any chemical fuel due to its low molecular weight and high heat of combustion.

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