RE-NEET 2026 Physics Angular Momentum MCQ Question

The angular momentum $L$ of a rotating object about a point is given by $L = I \omega$, where $I$ is the moment of inertia and $\omega$ is the angular velocity. For a thin disc, the moment of inertia about its center $O$ is $I_O = \frac{1}{2} m r^2$.

When calculating $L_A$ about point $A$ and $L_B$ about point $B$ (where $OB = 2 \times OA$), we use the parallel axis theorem:

$L_A = I_O \omega$ $L_B = I_O \omega + m d^2 \omega$

where $d = OA$ for $A$ and $d = 2OA$ for $B$. Thus,

$L_B = L_A + m (2OA)^2 \omega = L_A + 4 m OA^2 \omega$

This leads to $L_A/L_B = 1$, confirming the correct answer is $B$. Other options fail because they misinterpret the relationship between the distances and the contributions to angular momentum.