Answer: Ω = Mgr/Lω (where Lω = Iω is spin angular momentum).
- A Ω = Mgr/Lω (where Lω = Iω is spin angular momentum)
- B Ω = Iω/Mgr, the reciprocal of the correct expression
- C Ω = Mgr × Iω, multiplying instead of dividing the two quantities
- D Ω = g/ωr, omitting the mass and spin angular momentum entirely
Correct answer: A. Ω = Mgr/Lω (where Lω = Iω is spin angular momentum)
Explanation: Gyroscopic precession: Ω = τ/L = Mgr/(Iω). The torque from gravity causes the angular momentum vector to precess.
Torque about axis O equals the force F multiplied by the perpendicular distance r⊥ from the axis to the line of action of the force, producing rotation.
Concept context
Moment of inertia, torque, angular momentum, rolling motion. Very high JEE weightage.
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