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MHT CET 2026 (15 May, Shift 2) · Moment of Inertia & Radius of Gyration

Moment of Inertia & Radius of Gyration question from MHT CET 2026 (15 May, Shift 2)

Q4MHT CET 2026 · 15 MAY · SHIFT 2Easy

Moment of Inertia & Radius of Gyration

Moment of inertia of a disc of mass mm and radius RR about the centre of mass and perpendicular to plane is I1I_1 and moment of inertia of disc at a distance 2R3\frac{2R}{3} from centre and perpendicular to plane is I2I_2 then I1/I2I_1/I_2 is

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Answer: (b)

  1. I1=mR22I_1 = \frac{mR^2}{2} (centre, perpendicular to plane).
  2. Parallel axis at 2R3\frac{2R}{3}: I2=mR22+m4R29=1718mR2I_2 = \frac{mR^2}{2} + m\frac{4R^2}{9} = \frac{17}{18}mR^2
  3. I1I2=1/217/18=917\frac{I_1}{I_2} = \frac{1/2}{17/18} = \frac{9}{17}
  4. So the answer is (b) 917\frac{9}{17}.
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