Find out the number of waves made by a bohr electron is one complete revolation in its third orbit

Explanation

For an electron to be in a particular energy level of radius r, with de brogle wavelength `lambda`
`2pi r = n lambda`
(where n is the number of weaves in one revolution
`lambda = (h)/(mv)`
`rArr n = (2 pi rm v)/(h)`
For third orbit
`r = 0.53 xx 10^(-10) (n)^(2)m V = 2.165 xx 10^(6) xx ((1)/(n))`
`= 0.53 xx 10^(-10) xx (3)^(2)m = 2.165 xx 10^(6) xx (1)/(3)`
`= 4.77 xx 10^(-10)m = 0.721 xx 10^(6)`
Subsuitating the value of `r,v and h` we get `n = (2 pi rmv)/(h)`
`= (2 xx 3.14 xx 4.77 xx 10^(-10) xx 0.721 xx 10^(6) xx 9.1 xx 10^(-31))/(6.626 xx 10^(-34))`