Question

An excited state of H atom emits a photon of wavelength `lamda` and returns in the ground state. The principal quantum number of excited state is given by:
A. `sqrt(lambdaR(lambdaR-1))`
B. `sqrt((lambdaR)/((lambdaR-1)))`
C. `sqrt(lambdaR(lambdaR-1))`
D. `sqrt(((lambdaR-1))/(lambdaR))`

Answer 1

Correct Answer - 2
`1/lambda=R(1/n_(1)^(2)-1/n_(2)^(2)), n_(1)=1, n_(2)=?`
`1/lambda=R(1/1-1/n_(2)^(2)) rArr n_(2)^(2)=(Rlambda)/(Rlambda-1) rArr n_(2)=sqrt((lambdaR)/(lambdaR-1))`