JEE Main 12 Jan 2019 Evening Question 27

Question: 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? [JEE Main Online Paper Held On 12-Jan-2019 Evening]

Options:

A)

B)

C)

D)

Show Answer

Answer:

Correct Answer: B

Solution:

The moment of inertia I(x) at distance x is $ I(x)=\frac{2}{5}MR^{2}+Mx^{2} $ $ x^{2}=\frac{1}{M}(I(x)-\frac{2}{5}MR^{2}) $

This equation resembles the standard equation of parabola i.e., $ {{(x-h)}^{2}}=4p(y-k) $

Hence the curve will be parabolic.