wiz-icon
MyQuestionIcon
MyQuestionIcon
1
You visited us 1 times! Enjoying our articles? Unlock Full Access!
Question

Two circular discs A and B are of equal masses and thickness but made of metal with densities dA and dB (dA>dB). If their moments of inertia about an axis passing through their centres and perpendicular to circular faces are IA and IB, then

A
IA=IB
No worries! We‘ve got your back. Try BYJU‘S free classes today!
B
IA>IB
No worries! We‘ve got your back. Try BYJU‘S free classes today!
C
IA<IB
Right on! Give the BNAT exam to get a 100% scholarship for BYJUS courses
D
IAIB
No worries! We‘ve got your back. Try BYJU‘S free classes today!
Open in App
Solution

The correct option is C IA<IB
Step 1: Moment of inertia of circular discs [Ref. Fig.]
Moment of inertia of circular discs about an axis passing through their centres and perpendicular to circular faces:
IA=mAR2A2 ....(1)
IB=mBR2B2 ....(2)

Step 2: Solving equations
Divide equation (1) and (2)
IAIB=mAmB.(RARB)2=(RARB)2 [mA=mB]

Since, mA=mBdA×4πR2A=dB.4πR2B
(RARB)2=(dBdA)<1 [dA>dB]

IAIB=(dBdA)<1IA<IB

Hence, Option (C) is correct.

2114929_984284_ans_eac6f7026123416d8dc729c8f97b4b08.png

flag
Suggest Corrections
thumbs-up
0
Join BYJU'S Learning Program
similar_icon
Related Videos
thumbnail
lock
Moment of Inertia of Solid Bodies
PHYSICS
Watch in App
Join BYJU'S Learning Program
CrossIcon