JEE Main 2026 — Rotational Motion Question with Solution
JEE Main 2026 (23 January Shift 2)
Question
Suppose there is a uniform circular disc of mass and radius shown in figure. The shaded regions are cut out from the disc. The moment of inertia of the remainder about the axis of the disc is given by . The value of is .
Enter your answer
Show full solutionCorrect answer: 109
Correct answer
109
Step-by-step explanation
The moment of inertia of the complete disc about axis A is
.
Each removed circular region has radius and mass .
For each removed disc at distance from axis A, using the parallel axis theorem:
.
For two removed discs:
.
Therefore:
, so .
.
Each removed circular region has radius and mass .
For each removed disc at distance from axis A, using the parallel axis theorem:
.
For two removed discs:
.
Therefore:
, so .
Practice this on the real CBT interface
Solve this JEE Main question (and the rest of the Rotational Motion chapter) on PrepSharp's TCS iON-style CBT player — with timer, bookmarks and session analytics.
Solve interactively →About this question
This is a previous-year question from JEE Main 2026, 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.