ExamBro
ExamBro
JEE Mains · Physics · STD 11 - 6. system of particles and rotational motion

Consider two uniform discs of the same thickness and different radii \(R _{1}= R\) and \(R _{2}=\alpha R\) made of the same material. If the ratio of their moments of inertia \(I_{1}\) and \(I_{2}\), respectively, about their axes is \(I _{1}: I _{2}=1: 16\) then the value of \(\alpha\) is

  1. A \(\sqrt{2}\)
  2. B \(2\)
  3. C \(4\)
  4. D \(2 \sqrt{2}\)
Verified Solution

Answer & Solution

Correct Answer

(B) \(2\)

Step-by-step Solution

Detailed explanation

\(I_{1}=\frac{M R^{2}}{2}=\frac{\rho\left(\pi R^{2}\right) t \cdot R^{2}}{2}\) \(I \propto R^{4}\) \(\frac{I_{1}}{I_{2}}=\frac{R_{1}^{4}}{R_{2}^{4}}=\frac{1}{16}\) \(\therefore \frac{R_{1}}{R_{2}}=\frac{1}{2}\)
Same subject
Explore more questions on app