Question

Among the following, the quantity that is termed as gyro magnetic ratio is (Given: $m_e$ = mass of electron, $e$ = charge of electron)

• A. $\dfrac{e}{2m_e}$
• B. $\dfrac{e}{2\pi m_e}$
• C. $\dfrac{e}{4m_e}$
• D. $\dfrac{e}{4\pi m_e}$

Hint:

Gyromagnetic ratio is the magnetic moment per unit angular momentum: $\dfrac{\mu}{L} = \dfrac{e}{2m_e}$ for electron.

Answer 1

The Correct Option is A

The gyromagnetic ratio (also called magnetomechanical ratio) is the ratio of magnetic moment ($\mu$) to angular momentum ($L$).
For an electron in orbit: $\dfrac{\mu}{L} = \dfrac{e}{2m_e}$
Hence, correct option is $\dfrac{e}{2m_e}$.