Time taken by an electrons to complete one revolution in the Bohr orbit of the `H` atom is

Options

A. `(4pi^(2) mr^(2))/(nh)`
B. `(nh)/(4pi^(2)mr)`
C. `(2pimr)/(n^(2) h^(2))`
D. `(h)/(2pi mr)`

Answer

A

Explanation

By Bohr postulate, `mv r = n (h)/(2pi) or v = (nh)/(2pi mr)`
No. of revolution per sec
`= ("Velocity")/("Circumference of the orbit")`
`= (v)/(2pi r) = (nh)/(2pi mr) xx (1)/(2pi r) = (nh)/(4pi^(2) mr^(2))`
`:.` time taken for one revolution `= (4pi^(2) mr^(2))/(nh)`