JEE Main 2019 — Rotational Motion Question with Solution
From: JEE Main 2019 (Online) 11th January Morning Slot
Question
An equilateral triangle ABC is cut from a thin solid sheet of wood. (see figure) D, E and F are the mid-points of its sides as shown and G is the centre of the triangle. The moment of inertia of the triangle about an axis passing through G and perpendicular to the plane of the triangle is I0. If the smaller triangle DEF is removed from ABC, the moment of inertia of the remaining figure about the same axis is I. then :
This question includes a diagram. The text above accompanies the figure.
Choose an option
Show full solutionCorrect option: B
Correct answer
B
Step-by-step explanation
Suppose M is mass and a is side of larger triangle, then and will be mass and side length of smaller triangle.
So, = 0 =
So, = 0 =
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