Question

What is the correct value of Bohr magneton?

• A. $8.99 \times 10^{-24}\, A\, m^{2}$
• B. $9.27 \times 10^{-24}\, A\, m^{2}$
• C. $5.66 \times 10^{-24}\, A\, m^{2}$
• D. $9.27 \times 10^{-28}\, A\, m^{2}$

Answer 1

Answer: (B)

Bohr Magnetron
$\left(\mu_{l}\right)_{min} = \mu_{B} = \frac{e}{4\pi m_{e}}h$
Here, $e=1.6 \times 10^{-19}\, C$,
$h=6.64 \times 10^{-34}\,J\, s$
$m_{e} =9.1 \times 10^{-31}\,kg$
$\therefore \mu_{B}=\frac{1.60\times10^{-19}\times6.64\times10^{-34}}{4\times3.14\times9.1\times10^{-31}}$
$=9.27\times10^{-24}\,A\,m^{2}$