Moment of Inertia
Important Questions on Moment of Inertia
A circular disc is to be made using iron and aluminium. To keep its moment of inertia maximum about a geometrical axis, it should be so prepared that
A thin rod of length and mass is bent at the middle point as shown in the figure. Consider an axis passing through two middle the point and perpendicular to the plane of the bent rod. Then the moment of inertia about this axis is

Two rings have their moments of inertia in the ratio and their diameters are in the ratio . The ratio of their masses will be
The mass of a solid circular disc is , the circumference is and thickness is . The moment of Inertia of the disc about an axis tangential to the rim and perpendicular to the plane of rotation is
The ratio of the radii of gyration of a circular disc about a tangential axis in the plane of the disc and of a circular ring of the same radius about a tangential axis in the plane of the ring is,
Three-point masses are located at the vertices of an equilateral triangle of length . The moment of inertia of the system about an axis along the altitude of the triangle passing through is,
A thin uniform rectangular plate of mass is placed in plane as shown in the figure. The moment of inertia about -axis is and the moment of inertia about - axis is . The radius of gyration of the plate about the axis passing through and perpendicular to the plane of the plate is

A solid sphere is rotating in free space. If the radius of the sphere is increased keeping mass same which one of the following will not be affected?
A square plate of side and mass is lying on the horizontal plane. What will be the moment of inertia of the plate about an axis in the plane of the plate and at an angle of from one of its sides?

A disc of mass and radius is lying on the plane. The locus of all points on the plane about which the moment of inertia of the rod is same as that about will be,

The moment of Inertia of a semicircular ring about the centre is . Find the about a radially perpendicular point and the axis perpendicular to the plane of the ring as shown in the diagram.

A rigid body can be hinged about any point on the axis. When it is hinged in a such a way that the hinged position is at , the moment of inertia is given by, . Then, the -coordinate of centre of mass is,
A flywheel of mass and radius is revolving at a speed of . Its kinetic energy is
The of a uniform disc about the diameter is . Its about an axis perpendicular to its plane and passing through a point on its is
The moment of inertia of uniform circular disc about an axis passing through its centre is . Its about an axis perpendicular to its plane and just touching the will be
There are four-point masses each on the corners of a square of side length about one of its diagonals, the moment of inertia of the system is
A solid sphere of radius has a moment of inertia about its geometrical axis. If it is melted into a disc of radius and thickness . If it's moment of inertia about the tangential axis (which is perpendicular to the plane of the disc), is also equal to , then the value of is equal to
Moment of inertia of disc about the tangent parallel to plane is . The moment of inertia of disc about tangent and perpendicular to its plane is
M.I. of a thin uniform rod about the axis passing through its centre and to its length is . The rod is cut transversely into two halves, which are then riveted end to end. M.I. of the composite rod about the axis passing through its centre and to its length will be?
The moment of inertia of a uniform thin rod of length and mass about an axis passing through a point at a distance of from one of its ends and perpendicular to the rod is

