Q 11-06-231JEE MainJEE Main 2019 (12 Jan, Shift 2)Easy
The moment of inertia of a solid sphere, about an axis parallel to its diameter and at a distance of $x$ from it, is $I(x)$. Which one of the graphs represents the variation of $I(x)$ with $x$ correctly?
Answer: (A) see figure
By the parallel axis theorem
$$I(x) = \frac25MR^2 + Mx^2$$
This is a parabola in $x$ with a non-zero value $\frac25MR^2$ at $x = 0$ and zero slope there: graph (1).
Solution by Sreeraj P, M.Sc Physics