AP EAMCET202018 Sep 2020Evening ShiftPhysicsAtomic PhysicsActual
The second line of Balmer series has wavelength (4861 Å ). The wavelength of the first line of Balmer series is
Options
- A(1216 Å )
- B(6563 Å )
- C(4340 Å )
- D(4101 Å )
Correct answer
B. (6563 Å )
Step-by-step solution
Wavelength of the second line of Balmer series, ( ₂=4861 Å ) ( 1 ₂ =R ( 1 2^2 - 1 n^2 ) ) For second line, (n=4 ) ( aligned & & 1 ₂ & =R ( 1 2^2 - 1 4^2 ) & & 1 4861 & =R ( 1 4 - 1 16 ) & & 1 4861 & = 3 R 16 & & R & = 16 3 4861 (i) aligned ) Wavelength of first line ((n=3) ) of Balmer series is given as ( aligned 1 ₁ & =R ( 1 2^2 - 1 3^2 )=R ( 5 36 ) & = 16 3 4861 5 36 [From Eq. (i)] ₁ & = 3 4861 36 16 5 =6562.35 Å 6563 Å & aligned )