In the spectrum of hydrogen atom, the ratio of the longest wavelength in Lyman series to the longest wavelangth in the Balmer series is:

Options

A. `5/27`
B. `4/9`
C. `9/4`
D. `27/5`

Answer

A

Explanation

For Lyman series
`1/(lambda_(1))=R(1/(1^(2))-1/(2^(2)))=3/4R.......(i)`
for Balmer series
`1/(lambda_(2))=R(1/(2^(2))-1/(3^(2)))=5/36R.......(ii)`
Dividing (ii) and (i)
`(lambda_(1))/(lambda_(2))=((5//36)R)/((3//4)R)=5/27`