The ratio of longest wavelength lines in the Balmer and Paschen series of hydrogen spectrum is

• A

  $\frac{5}{36}$
• Correct answer
  B

  $\frac{7}{20}$
• C

  $\frac{7}{144}$
• D

  $\frac{5}{27}$

Solution

On dividing Eq. (B) by Eq. (A), we get $\frac{\lambda_{B L}}{\lambda_{P L}}=\frac{7}{20}$

Hence, the correct answer is option: 'B'.