Seven identical discs are arranged in a planar pattern,so as to touch each other as shown in the figure. Each disc has mass $m$ and radius $R$. What is the moment of inertia of the system of six outer discs about an axis passing through the centre of the central disc and normal to the plane of all discs?

  • A
    $27 m R^2$
  • B
    $100 m R^2$
  • C
    $55 \frac{m R^2}{2}$
  • D
    $85 \frac{m R^2}{2}$

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$A$ thin rod has a length of $1 \ m$ and a mass of $0.6 \ kg$. The moment of inertia of the rod about an axis perpendicular to its length and passing through a point $20 \ cm$ from one end is ................... $kg \cdot m^2$ (the width of the rod is negligible).

$M$ and $R$ are the mass and radius of a disc. $A$ small disc of radius $R/3$ is removed from the bigger disc as shown in the figure. The moment of inertia of the remaining part of the bigger disc about an axis $\text{AB}$ passing through the centre $O$ and perpendicular to the plane of the disc is $\frac{4}{x} MR^2$. The value of $x$ is . . . . . . .

The moment of inertia of a uniform square plate about an axis perpendicular to its plane and passing through the centre is $\frac{Ma^{2}}{6}$,where $M$ is the mass and $a$ is the side of the square plate. The moment of inertia of this plate about an axis perpendicular to its plane and passing through one of its corners is

$A$ rigid body of mass $m$ rotates with angular velocity $\omega$ about an axis at a distance $d$ from its center of mass. The radius of gyration about an axis passing through the center of mass $G$ and parallel to the given axis is $K$. What is the rotational kinetic energy of the body?

Match Column-$I$ with Column-$II$:
Column-$I$Column-$II$
$(1)$ Perpendicular Axis Theorem$(a)$ $I = I_C + Md^2$
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