Verified Solution • 2025–26 Session
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QNEET-2016-Ph-1082: NEET 2016 Physics - Class 11 NEET-2016-Ph-1082 Solution: From a disc of radius R and mass M a circular hole of diameter…
From a disc of radius R and mass M a circular hole of diameter R whose rim passes through the centre is cut. What is the moment of inertia of the remaining part of the disc about a perpendicular axis passing through the centre?
Multiple Choice Options
- A 11 MR 2 /32
- B 9 MR 2 /32
- C 15 MR 2 /32
- D 13 MR 2 /32
Step-by-Step Verified Solution
Moment of inertia of complete disc about
point 'O'.
I T o t a l d i s c = M R 2 2
Mass of removed disc
M Removed = M 4 ( M a s s _ a r e a )
Moment of inertia of removed disc about point
'O'.
I Removed (about same perpendicular axis)
= I c m + m x 2
= M 4 ( R / 2 ) 2 2 + M 4 ( R 2 ) 2 = 3 M R 2 32
Therefore the moment of inertia of the remaining
part of the disc about a perpendicular axis
passing through the centre,
I Remaing disc = I Total � I Removed
= M R 2 2 _ 3 32 M R 2 = 13 32 M R 2