Question

The ratio of the frequencies of the long wave length its of Lyman Balmer series of hydrogen spectrum is

Options

• 27 : 5

• 5 : 27

• 4 : 1

• 1 : 4

Answer 1

27 : 5

Explanation:

For Lyman series `1/(lambdam)` = `R(1/1^2 - 1/2^2) = (3R)/4`

For Ballmer series, `1/(lambdam)` = `R(1/2^2 - 1/3^2) = (5R)/36`

Divided `(lambdam)/(lambda^2m) xx (5R)/36 xx 4/(4R) = 5/27 (vm)/(v^1m) = 27/5`