Q 12-12-105JEE MainJEE Main 2020 (8 Jan, Shift 1)Easy
The graph which depicts the results of the Rutherford gold foil experiment with $\alpha$-particles is: ($\theta$: scattering angle; $Y$: number of scattered $\alpha$-particles detected; plots are schematic and not to scale)
Answer: (D) see figure
Most $\alpha$-particles pass almost undeflected and only very few are scattered through large angles. The number scattered falls very steeply with angle ($N \propto \dfrac{1}{\sin^4(\theta/2)}$), so $Y$ is very large at small $\theta$ and drops rapidly to a small value at large $\theta$. This is graph (4).
Solution by Sreeraj P, M.Sc Physics