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Question
Choose the correct option.
Select correct statement about the formula (expression) of moment of inertia (M.I.) in terms of mass M of the object and some of its distance parameter/s, such as R, L, etc.
Options
Different objects must have different expressions for their M.I.
When rotating about their central axis, a hollow right circular cone and a disc have the same expression for the M.I.
Expression for the M.I. for a parallelepiped rotating about the transverse axis passing through its centre includes its depth.
Expression for M.I. of a rod and that of a plane sheet is the same about a transverse axis.
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Solution
When rotating about their central axis, a hollow right circular cone and a disc have the same expression for the M.I.
Explanation:
Expression for M.I of a hollow right circular cone is given by:
Here, m and R are mass and radius of gyration respectively.
And expression for M.I of disc is given by:
Here, m and R are mass and radius of gyration, respectively.
Thus, when rotating about their central axis, a hollow right circular cone and a disc have the same expression for the M.I.
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