An excited `He^(+)` ion emits photon of wavelength `lamda` in returning to ground state from `n^(th)` orbit. If ʻR’ is Rydberg constant, then

Options

A. `n=sqrt((4 lamda R)/(4 lamda R-1))`
B. `n=sqrt((4 lamda R)/(4 lamda R+1))`
C. `n=sqrt((4 lamda R-1)/(4 lamda R))`
D. `n=sqrt((4 lamda R+1)/(4 lamda R))`

Answer

A

Explanation

`(1)/(lamda) = Rxx 2^(2) [(1)/(1)-(1)/(n^(2))] rArr (1)/(lamda) =4R [(n^(2)-1)/(n^(2))]`
`(1)/(n^(2))=(4 lamda R-1)/(4lamda R) rArr n = sqrt((4 lamda R)/(4 lamda R-1))`