Most Repeated Questions in NEET Exam - Important Question for NEET 2024

Moment Of Inertia Of A Rod MCQ - Practice Questions with Answers

Edited By admin | Updated on Sep 25, 2023 25:23 PM | #NEET

Quick Facts

  • Moment of inertia of a Rod is considered one of the most asked concept.

  • 10 Questions around this concept.

Solve by difficulty

The moment of inertia of a uniform cylinder of length land radius R about its perpendicular bisector is I.  What is the ratio \frac{l}{R} such that the moment of inertia is minimum?

Three identical rods, each of length l are joined to form a rigid equilateral triangle. Its radius of gyration about an axis passing through a corner and perpendicular to the plane of the triangle is 

Four identical thin rods each of mass $M$ and length $\ell$, form a square frame. The moment of inertia of this frame about an axis through the centre of the square and perpendicular to its plane is :

There is a rod of length L and mass M; one line is passing through the centre of the rod and another line is passing through the end of the rod; The radius of gyrations ratio of this rod for the given cases (concerning the line positions) centre/end is 

A thin rod of length \mathrm{l} is suspended from a point from on its length which is at a distance \mathrm{x} from its centre, for what value of \mathrm{x} time period of oscillation will be minimum -
 

A tube of length 1m is filled completely with an incompressible liquid with of mass 1kg and closed at both ends. The tube is rotated in a horizontal plane about one of its ends with a uniform angular velocity of 2rad/s. The force exerted by the liquid ath the other end is 

Concepts Covered - 1

Moment of inertia of a Rod

Let I=Moment of inertia of a ROD about an axis through its center and perpendicular to it

To calculate I (Moment of inertia of rod)

Consider a uniform straight rod   of length L, mass M and having center C

 mass per unit length of the rod = $\lambda=\frac{M}{L}$

Take a small element of mass dm with length dx at a distance x from point C.

$$
\begin{aligned}
d m & =\lambda \cdot d x=\frac{M}{L} \cdot d x \\
\Rightarrow d I & =x^2 d m
\end{aligned}
$$


Now integrate this dl between the limits $x=-\frac{L}{2}$ to $\frac{L}{2}$

$$
I=\int d I=\int x^2 d m=\int_{\frac{-L}{2}}^{\frac{L}{2}} \frac{M}{L} x^2 * d x=\frac{M}{L} \int_{\frac{-L}{2}}^{\frac{L}{2}} x^2 d x=\frac{M L^2}{12}
$$
 

 

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Moment of inertia of a Rod

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