The de-Broglie wavelength of an electron in the first Bohr orbit is

Options

A. Equal to one fourth the circumference of the first orbit
B. Equal to half the circyumference of the first orbit
C. Equal to twice the circumference of the first orbit
D. Equal to the circulference of the first orbit

Answer

D

Explanation

`mvr_(n) = (nh)/(2pi) rArr pr_(n) = (nh)/(2pi) rArr (h)/(lambda) xx r_(n) = (nh)/(2pi)`
`rArr lambda = (2pir_(n))/(n)`, for first orbit `n = 1` so `lambda = 2pi r_(1)`
`=` circumference of first orbit