If ₁ and ₂ are the wavelengths of the first members of the Lyman and Paschen series respectively, then ₁: ₂ is

Step-by-step solution

For first line of Lyman series, n₁=1 and n₂=2 1 ₁ =R ( 1 1^2 - 1 2^2 )=R (1- 1 4 )= 3 R 4 For first line of Paschen series n₁=3 and n₂=4 1 ₂ =R ( 1 3^2 - 1 4^2 )=R ( 1 9 - 1 16 )= 7 R 144 ₁ ₂ = 7 R 144 4 3 R = 7 108