Q 11-06-048JEE MainJEE Main 2026 (5 Apr, Shift 2)Easy
A wheel initially at rest is subjected to a uniform angular acceleration about its axis. In the first $2$ s it rotates through an angle $\theta_1$ and in the next $2$ s it rotates through an angle $\theta_2$. The ratio $\dfrac{\theta_2}{\theta_1}$ is ______.
Answer: (B) $3$
Concept. From rest with constant $\alpha$, $\theta=\tfrac12\alpha t^2$: the angles in successive equal intervals go as $1:3:5:\dots$
Step 1. Angles. $\theta_1=\tfrac12\alpha(2)^2=2\alpha$; $\theta_1+\theta_2=\tfrac12\alpha(4)^2=8\alpha\Rightarrow\theta_2=6\alpha$.
Step 2. Ratio. $\dfrac{\theta_2}{\theta_1}=3$.
Answer. $3$ (Option B).
Solution by Sreeraj P, M.Sc Physics
