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MHT CET 2026 (15 May, Shift 1) · Moment of Inertia & Radius of Gyration

Moment of Inertia & Radius of Gyration question from MHT CET 2026 (15 May, Shift 1)

Q10MHT CET 2026 · 15 MAY · SHIFT 1Medium

Moment of Inertia & Radius of Gyration

A square frame ABCD is formed by 4 identical rods each of mass mm and length ℓ\ell. This frame is in XY plane such that side AB coincides with x-axis and side AD along y-axis. The moment of inertia of the frame about x-axis is

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Answer: (a)

  1. Rod AB lies on the x-axis: I=0I = 0.
  2. Rods AD and BC are perpendicular to x-axis with one end on it: mℓ23\frac{m\ell^2}{3} each.
  3. Rod DC is parallel to x-axis at distance ℓ\ell: mℓ2m\ell^2.
  4. I=0+2mℓ23+mℓ2=5mℓ23I = 0 + \frac{2m\ell^2}{3} + m\ell^2 = \frac{5m\ell^2}{3}, so the answer is (a).
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