JEE Main 2020 — Rotational Motion Question with Solution
From: JEE Main 2020 (Online) 7th January Morning Slot
Question
As shown in the figure, a bob of mass m is tied by a massless string whose other end portion is wound on a fly wheel (disc) of radius r and mass m. When released from rest the bob starts falling vertically. When it has covered a distance of h, the angular speed of the wheel will be:This question includes a diagram. The text above accompanies the figure.
Choose an option
Show full solutionCorrect option: C
Correct answer
C
Step-by-step explanation
mgh = KE
=
For no slipping, v = R
mgh =
mgh =
=
=
For no slipping, v = R
mgh =
mgh =
=
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This is a previous-year question from JEE Main 2020, covering the Rotational Motion chapter of Physics. PrepSharp catalogues every PYQ from JEE Main with a verified answer key and step-by-step solution prepared by IIT alumni — so you can search by chapter, topic or year and revise efficiently.