Q151 / 160 · AP EAMCET 2020 (18 Sep Shift 2) · Physics
A solid cylinder of mass \(M\) and radius \(R\) rolls on a flat surface. Its moment of inertia about the line of contact is
- Correct answerA\(\left(\frac{3}{2}\right) M R^2\)
- B\(M R^2\)
- C\(\left(\frac{2}{3}\right) M R^2\)
- D\(2 M R^2\)
Solution
Moment of inertia of solid cylinder of radius \(R\) and mass \(M\) about its axis is given as
\(I_{\mathrm{CM}}=\frac{1}{2} M R^2\) ...(i)
Moment of inertia about contact line \(A B\) is given

According to parallel axes theorem, i.e. \(\quad I_{A B}=I_{\mathrm{CM}}+M R^2=\frac{1}{2} M R^2+M R^2=\frac{3}{2} M R^2\)

According to parallel axes theorem, i.e. \(\quad I_{A B}=I_{\mathrm{CM}}+M R^2=\frac{1}{2} M R^2+M R^2=\frac{3}{2} M R^2\)
Hence, the correct answer is option: 'A'.