If the wavelength of photon emitted due to transition of electron from third orbit to first orbit in a hydrogen atom is `lambda` then the wavelength of photon emitted due to transition of electron from fourth orbit to second orbit will be

Answer

`04.74`

Explanation

Transition of electrons from the third orbit to the first orbit, `1/lamda =R[1/(1^2) -1/(3^2)]`
`implies lamda = 9/(8R)`
Transition of electrons from the fourth orbit to the second orbit,
`1/(lamda.)=R[1/2^2-1/4^2]implieslamda.=16/(3R)`
Now, `(lamda.)/lamda = 16/(3R)xx(8R)/9 =128/27`
`implies lamda. = (128)/27lamda = 4.74 lamda`