Q.

Two iron solid discs of negligible thickness have radii R1 and R2 and moment of inertia I1 and I2, respectively. For R2=2R1, the ratio of I1 and I2 would be 1/x, where x = __________.          [2025]


Ans.

(16)

Given, R2=2R1

M1=σ×πR12=Mo

M2=σ×πR22=σ×π[2R1]2=σ×4πR12=4Mo

I1I2=M1R122M2R222=M1R12M2R22=14×14=116