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Two discs of same moment of inertia ( I ) are rotating in same sense about their regular axis passing through centre and perpendicular to the plane…

NEET UG 2017 — Physics Mechanics

2017mcqhard

Two discs of same moment of inertia (I)( I )(I) are rotating in same sense about their regular axis passing through centre and perpendicular to the plane of disc with angular velocities ω1{\omega }_{1}ω1​ and ω2{\omega }_{2}ω2​. They are brought into contact face to face coinciding the axis of rotation. The expression for loss in energy during this process is

Official previous-year question

Held on 30 Apr 2017 · Verified 9 Jul 2026.

Options

  1. A

    12I(ω1+ω2)2\frac{1}{2}I{({\omega }_{1}+{\omega }_{2})}^{2}21​I(ω1​+ω2​)2

  2. B

    14I(ω1−ω2)2\frac{1}{4}I{({\omega }_{1}-{\omega }_{2})}^{2}41​I(ω1​−ω2​)2

  3. C

    I(ω1−ω2)2I{({\omega }_{1}-{\omega }_{2})}^{2}I(ω1​−ω2​)2

  4. D

    18(ω1−ω2)2\frac{1}{8} {({\omega }_{1}-{\omega }_{2})}^{2}81​(ω1​−ω2​)2

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