If , `lambda_(1)` and `lambda_(2)` are the wavelength of the numbers of the Lyman and Paschen seri respectively. Then `lambda_(1):lambda_(2)=`.....

Options

A. `1:3`
B. `7:50`
C. `1:30`
D. `7:108`

Answer

D

Explanation

`(1)/(lambda_(1))=R[(1)/(1^(2))-(1)/(2^(2))]=R[1-(1)/(4)]=(3R)/(4)`
`:.lambda_(1)=(4)/(3R)....(1)`
`(1)/(lambda_(2))=R[(1)/(3^(2))-(1)/(4^(2))]`
`=R[(1)/(9)-(1)/(16)]=R[(7)/(144)]`
`:.lambda_(2)=(144)/(7R)...(2)`
`:.(lambda_(1))/(lambda_(2))=((4)/(3R))/((144)/(7R))`
`:.lambda_(1):lambda_(2)=(7)/(108)`