Question

If the angular momentum of electron is $\overrightarrow{J}$ then its magnetic moment will be -

• A. $\frac{eJ}{m}$
• B. $\frac{eJ}{2m}$
• C. eJ2m
• D. $\frac{2m}{eJ}$

Answer 1

Answer: (B)

$\frac{eJ}{2m}$

Angular momentum $J=m\omega r^2$

where,

$\omega$ is the angular velocity

$r$ is the radius of the orbit

Magnetic moment, $\mu =iA=\frac{e\omega }{2\pi }\pi r^2$

$\frac{\mu }{J}=\frac{\frac{e\omega }{2\pi }\pi r^2}{2\omega r^2}=\frac{e}{2m}$

$⟹\mu =\frac{eJ}{2m}$