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Saturday, 31 October

JEE Main 2021 · PhysicsMultiple choiceSingle correctMediumApplication

JEE Main 26 February 2021, Shift 1, Physics Q10

Question 10 of 90 in this shift, Physics question 10 of 30, Section A.

A particle is moving with uniform speed along the circumference of a circle of radius R under the action of a central fictitious force F which is inversely proportional to R3\mathrm{R}^{3}. Its time period of revolution will be given by :
  1. (1)T∝R32\mathrm{T}\propto\mathrm{R}^{\frac{3}{2}}
  2. (2)T∝R43\mathrm{T}\propto\mathrm{R}^{\frac{4}{3}}
  3. (3)T∝R2\mathrm{T}\propto\mathrm{R}^{2}Official answer
  4. (4)T∝R52\mathrm{T}\propto\mathrm{R}^{\frac{5}{2}}

Official answer

Option 3

NTA final key.

Chapter
Motion in a Plane
Topic
Circular Motion
Idea tested
Centripetal Acceleration

Same idea in other shifts

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Question text from the official JEE Main paper published by NTA; answer from the final answer key. Chapter, topic and idea tags, difficulty and skill are Lumi’s. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.