CameraIcon
CameraIcon
SearchIcon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

A solid sphere of mass M, radius R and having moment of inertia about an axis passing through the centre of mass as I, is recast into a disc of thickness t, whose moment of inertia about an axis passing through its edge and perpendicular to its plane remains I. Then, radius of the disc will be:

A
2R15
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
B
R215
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
4R15
No worries! We‘ve got your back. Try BYJU‘S free classes today!
D
2R15
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is A 2R15
Let R1 be the radius of the disc formed and also mass of the disc and the sphere must be same.
Moment of inertia of the disc about an axis passing through the centre and perpendicular to the plane, I=12MR21
Moment of inertia of the disc about an axis passing through the edge and perpendicular to the plane, I′′=I+MR21=32MR21
For sphere: I=25MR2
Given: I′′=I
32MR21=25MR2R1=2R15

447777_42747_ans_7098409bd0ba43e298cda0f9f5a7a017.jpg

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Problems
PHYSICS
Watch in App
Join BYJU'S Learning Program
CrossIcon