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Saturday, 31 October

JEE Main 2026 · PhysicsMultiple choiceDiagram basedMediumMulti-step

JEE Main 4 April 2026, Shift 2, Physics Q35

Question 35 of 75 in this shift, Physics question 10 of 25, Section A.

A uniform disc of radius RR and mass MM is free to oscillate about the axis AA as shown in the figure. For small oscillations the time period is ________. (g is acceleration due to gravity)

The figure, in words

Uniform disc of radius R and mass M (centre marked, radius R drawn); axis A is a horizontal line tangent to the disc at its top point A, about which the disc oscillates (rotation arrow shown); M labelled at the bottom.
  1. (1)2π5R4g2\pi\sqrt{\frac{5R}{4g}}Official answer
  2. (2)2π2R3g2\pi\sqrt{\frac{2R}{3g}}
  3. (3)2π3R2g2\pi\sqrt{\frac{3R}{2g}}
  4. (4)2π3Rg2\pi\sqrt{\frac{3R}{g}}

Official answer

Option 1

NTA final key.

Chapter
Oscillations
Topic
Pendulums
Idea tested
Physical Pendulum Period

Same topic in other shifts

All Pendulums questions
  1. 5 Apr 2024, Shift 1 · Q40A simple pendulum doing small oscillations at a place R height above earth surface has time period of T1=4T_1 = 4 s. T2T_2 would be it's…MediumSingle correct
  2. 1 Feb 2024, Shift 1 · Q36If R is the radius of the earth and the acceleration due to gravity on the surface of earth is g = π2\pi^2 m/s2^2, then the length of the…MediumSingle correct
  3. 30 Jan 2024, Shift 2 · Q60A simple pendulum is placed at a place where its distance from the earth's surface is equal to the radius of the earth. If the length of…MediumNumerical value
  4. 6 Apr 2023, Shift 2 · Q60A simple pendulum with length 100 cm and bob of mass 250 g is executing S.H.M. of amplitude 10 cm. The maximum tension in the string is…MediumNumerical value
  5. 25 Jul 2022, Shift 2 · Q43The length of a seconds pendulum at a height h = 2R from earth surface will be : (Given R = Radius of earth and acceleration due to…MediumSingle correct
  6. 28 Jul 2022, Shift 2 · Q6Assume there are two identical simple pendulum clocks. Clock - 1 is placed on the earth and Clock - 2 is placed on a space station located…MediumSingle correct

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. This question needs a figure we do not reproduce; it is described in words above. Lumi analyses 108 of the 174 JEE Main shifts held from 2017 to 2026.