Balmer gave an equation for wavelength of visible region of H-spectrum as `barv =(n^2 - 4)/(Kn^2)` where n = principal quantum number of energy level, K = constant terms.of R (Rydberg constant). The value of K in terms of R is:

Options

A. R
B. `R/2`
C. `4/R`
D. `5/R`

Answer

C

Explanation

`bar(upsilon) =R[(1)/(2^2) - 1/(n^2)] = 1/(lambda)`
After simplification of this equation and then comparing with `bar(v) = (n^2 - 4)/(Kn^2) ` we get K = 4/R