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GS Paper IUPSC Prelims 2000
Health & Medicine
Question No. 265Interactive Test Mode
00:00
+2-0.66

Q265. Assertion (A): In a motion picture, usually 24 frames are projected every second over the whole length of the film. Reason (R): An image formed on the retina of the eye persists for about 0.1 s after the removal of stimulus.

Assertion (A): In a motion picture, usually 24 frames are projected every second over the whole length of the film. Reason (R): An image formed on the retina of the eye persists for about 0.1 s after the removal of stimulus.

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 2000 • Science and Technology

Correct Answer: Option (C) — A is true but R is false

Concept & Option Breakdown

Standard Reference Verified

Assertion (A) is true: 24 frames per second is the worldwide standard cinema projection rate to ensure human perception of smooth, continuous motion. Reason (R) is false: The persistence of vision in the human eye lasts for approximately 1/16th of a second (~0.0625 s), not 0.1 s (1/10 s).

Elimination Heuristic & Exam Approach

Persistence of human vision is standardly 1/16 of a second.

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Question Specifications & Syllabus Mapping

Examination & YearUPSC Civil Services Preliminary Examination 2000 (Q265)
Paper & Marking SchemeGS Paper I • 2 Marks (-0.66 Negative for incorrect response)
Syllabus Subject & TopicScience and Technology → Health & Medicine
Official Answer KeyOption (C) — A is true but R is false

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Frequently Asked Questions — UPSC Prelims 2000 Q265

What is the official answer for UPSC Prelims 2000 GS Paper I Question 265 (Science and Technology)?

The official UPSC answer key for this 2000 Science and Technology (Health & Medicine) question is Option (C): "A is true but R is false". Correct attempts carry 2 Marks with -0.66 Negative penalty for wrong answers.

Which UPSC Prelims syllabus topic does this 2000 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?

Persistence of human vision is standardly 1/16 of a second.

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