The M.I. of uniform circular disc about a diameter is I. its M.I. about an axis perpendicular to its plane passing through a point on its rim will be
(a) 4 I
(b) 6 I
(c) 8 I
(d) 9 I

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Dear Student

MI of disc about an axis through its axis = MR²/4
MI of disc about diameter = I = MR²/4
or, MR² = 4I  ----- (1)

Now, MI of the same disc about an axis passing through a point on rim and perpendicular to the plane
= (MR ²/2) + MR²       (Parallel axis theorem)
= 3/2 *(MR²)
=3/2 * (4I)

= 6I

Therefore, (b) is the correct option.

Regards