Physics Question from JEE Main 2025 · 3 April, Shift 2

Given below are two statements : one is labelled as Assertion $A$ and the other is labelled as Reason $R$. Assertion $A$ : If oxygen ion $\left(\text{O}^{-2}\right)$ and Hydrogen ion $\left(\text{H}^{+}\right)$ enter normal to the magnetic field with equal momentum, then the path of $\text{O}^{-2}$ ion has a smaller curvature than that of $\text{H}^{+}$. Reason $R$ : A proton with same linear momentum as an electron will form a path of smaller radius of curvature on entering a uniform magnetic field perpendicularly. In the light of the above statements, choose the correct answer from the options given below