Q.

The ratio of the wavelengths of the light absorbed by a hydrogen atom when it undergoes n=2n=3 and n=4n=6 transitions, respectively, is            [2025]
 

1 19  
2 14  
3 136  
4 116  

Ans.

(2)

From Rydberg’s formula

1λ=RH[1ni2-1nf2]

For ni=2,nf=3,

1λ1=RH[122-132]=RH[536]                                                      ...(i)

For ni=4,nf=6,

1λ2=RH[142-162]=RH[116-136]=RH[5144]                      ...(ii)

On dividing eqn. (ii) by (i), we get

λ1λ2=RH[5144]×1RH[365]

λ1λ2=14