Question

The moment of inertia (MI) of a disc of radius \( R \) and mass \( M \) about its central axis is:

• A. \( \frac{MR^2}{4} \)
• B. \( \frac{MR^2}{2} \)
• C. \( MR^2 \)
• D. \( \frac{3MR^2}{2} \)

Hint:

The moment of inertia depends on both the mass distribution and the axis of rotation. For standard shapes, it's helpful to memorize the commonly used formulas.

Answer 1

The Correct Option is B

Step 1: The moment of inertia for a solid disc rotating about its central axis is expressed as: \[ I = \frac{1}{2} MR^2. \] Step 2: By comparing with the provided options, the correct answer is option (b).