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GS Paper IUPSC Prelims 1998
Health & Medicine
Question No. 355Interactive Test Mode
00:00
+2-0.66

Q355. Assertion (A): Phenyl is used as a household germicide. Reason (R): Phenyl is phenol derivative and phenol is an effective germicide.

Assertion (A): Phenyl is used as a household germicide. Reason (R): Phenyl is phenol derivative and phenol is an effective germicide.

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Official Answer Key & Detailed Solution

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Official UPSC Answer KeyUPSC Prelims 1998 • Science and Technology

Correct Answer: Option (A) — Both A and R are true and R is the correct explanation of A

Concept & Option Breakdown

Standard Reference Verified
  • Assertion (A) is true: Phenyl formulations (phenolic disinfectants) are standard household germicides.
  • Reason (R) is true: Phenyl preparations are derived from coal tar fractions rich in phenol/cresols, which act as potent germicides by denaturing bacterial proteins and disrupting cell membranes. Thus, R correctly explains A.
Elimination Heuristic & Exam Approach

Phenol (carbolic acid) was the original antiseptic used by Joseph Lister, explaining the germicidal mechanism of phenolic household disinfectants.

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Question Specifications & Syllabus Mapping

Examination & YearUPSC Civil Services Preliminary Examination 1998 (Q355)
Paper & Marking SchemeGS Paper I • 2 Marks (-0.66 Negative for incorrect response)
Syllabus Subject & TopicScience and Technology → Health & Medicine
Official Answer KeyOption (A) — Both A and R are true and R is the correct explanation of A

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Frequently Asked Questions — UPSC Prelims 1998 Q355

What is the official answer for UPSC Prelims 1998 GS Paper I Question 355 (Science and Technology)?

The official UPSC answer key for this 1998 Science and Technology (Health & Medicine) question is Option (A): "Both A and R are true and R is the correct explanation of A". Correct attempts carry 2 Marks with -0.66 Negative penalty for wrong answers.

Which UPSC Prelims syllabus topic does this 1998 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?

Phenol (carbolic acid) was the original antiseptic used by Joseph Lister, explaining the germicidal mechanism of phenolic household disinfectants.

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