Q 12-04-149JEE MainJEE Main 2022 (25 Jul, Shift 1)Easy
The magnetic moment of an electron ($e$) revolving in an orbit around the nucleus with an orbital angular momentum $\vec L$ is given by
Answer: (B) $\vec\mu_L = -\dfrac{e\vec L}{2m}$
For an orbiting charge $\mu = IA = \dfrac{ev}{2\pi r}\pi r^2 = \dfrac{evr}{2} = \dfrac{e}{2m}L$. The electron is negative, so the magnetic moment is opposite to $\vec L$: $\vec\mu_L = -\dfrac{e\vec L}{2m}$.
Solution by Sreeraj P, M.Sc Physics