Question

Magnetic moment of orbital electron in first orbit is ${\mu }_B$ then magnetic moment of that electron on third orbit

• A. ${\mu }_n$
• B. $\frac{{\mu }_B}{3}$
• C. $3{\mu }_B$
• D. $9{\mu }_B$

Answer 1

The correct option is C $3{\mu }_B$

Given: magnetic moment of electron in first orbit$={\mu }_B$

To find: magnetic moment of electron in $3^{rd}orbit,{\mu }_3=?$

Solution: As we know that,

${\mu }_n=n\frac{eh}{4\pi m_e}$

So, in $3^{rd}orbit,moment$ $is,$

${\mu }_3=3\frac{eh}{4\pi m_e}$ $....\left(1\right)$

and bohr magneton has a value,

${\mu }_B=\frac{eh}{4\pi m_e}$ $...\left(2\right)$

On equating $\left(1\right),\left(2\right),$we get

${\mu }_3=3{\mu }_B$

hence,

The correct opt :C