Question

According to Bohr’s theory, the angular momentum of an electron in 5th orbit is :

• A. $25\frac{h}{\pi }$
• B. $1.0\frac{h}{\pi }$
• C. $10\frac{h}{\pi }$
• D. $2.5\frac{h}{\pi }$

Answer 1

Answer: (D)

Angular momentum of an electron
$=mvr=\frac{nh}{2\pi }$ (n is orbit number)
in 5th orbit $=\frac{5h}{2\pi }$
$=\frac{2.5h}{\pi }$