Question
According to Bohr's theory, the angular momentum of an electron in 5th orbit is
A.
$$\frac{{10h}}{\pi }$$
B.
$$\frac{{2.5h}}{\pi }$$
C.
$$\frac{{25h}}{\pi }$$
D.
$$\frac{{1.0h}}{\pi }$$
Answer :
$$\frac{{2.5h}}{\pi }$$
Solution :
Angular momentum of an electron in $${n^{th}}$$ orbit is given by
$$mvr = \frac{{nh}}{{2\pi }}$$
For $${\text{ }}n{\text{ }} = {\text{ }}5,$$ we have
Angular momentum of electron
$$\eqalign{
& = \frac{{5h}}{{2\pi }} \cr
& = \frac{{2.5h}}{\pi } \cr} $$