If the moment of inertia of a disc about an axis tangential and parallel to its surface be I, then what will be the moment of inertia about the axis tangential but perpendicular to the surface?

Question

If the moment of inertia of a disc about an axis tangential and parallel to its surface be I, then what will be the moment of inertia about the axis tangential but perpendicular to the surface? (A)  (6/5)I (B)  (3/4)I (C)  (3/2)I (D)  (5/4)I

Tardigrade Admin · Accepted Answer

MI of disc about tangent in a place = (5/4)MR2=I MR2= (4/5)I MI of disc about tangent perpendicular to plane I'= (3/2)MR2 I'= (3/2)( (4/5)I)= (6/5)I

Q. If the moment of inertia of a disc about an axis tangential and parallel to its surface be $I$ , then what will be the moment of inertia about the axis tangential but perpendicular to the surface?

$\frac{6}{5} I$

$\frac{3}{4} I$

$\frac{3}{2} I$

$\frac{5}{4} I$

MI of disc about tangent in a place
$= \frac{5}{4} M R^{2} = I M R^{2} = \frac{4}{5} I$
$M I$ of disc about tangent perpendicular to plane
$I^{'} = \frac{3}{2} M R^{2}$
$I^{'} = \frac{3}{2} (\frac{4}{5} I) = \frac{6}{5} I$

Q. If the moment of inertia of a disc about an axis tangential and parallel to its surface be I, then what will be the moment of inertia about the axis tangential but perpendicular to the surface?

56​I

43​I

23​I

45​I