Q.

For a hydrogen atom, the ratio of the largest wavelength of Lyman series to that of the Balmer series is.          [2025]

1 5 : 36  
2 5 : 27  
3 3 : 4  
4 27 : 5  

Ans.

(2)

Largest wavelength of Lyman series,

1λ1=R[1114]=3R4

λ1=43R           ... (i)

Largest wavelength of Balmer series

1λ2=R[1419]=5R36

λ2=365R

Then, λ1λ2=527