Question

Let $F_{1}$ be the frequency of second line of Lyman series and $F_{2}$ be the frequency of first line of Balmer series then frequency of first line of Lyman series is given by

• A. $F_{1}-F_{2}$
• B. $F_{1}+F_{2}$
• C. $F_{2}-F_{1}$
• D. $\frac{F_{1} \,F_{2}}{F_{1}+F_{2}}$

Answer 1

Answer: (A)

$F_{1}=R_{c}\left[\frac{1}{n_{1}^{2}}-\frac{1}{n_{3}^{2}}\right]\,\,\,...(i) $
$F_{2}=R_{c}\left[\frac{1}{n_{2}^{2}}-\frac{1}{n_{3}^{2}}\right]\,\,\,...(ii)$
Subtracting (ii) from (i)
$F=R_{c}\left[\frac{1}{n_{1}^{2}}-\frac{1}{n_{2}^{2}}\right]$
$F=F_{1}-F_{2}$