Easy MCQ +4 / -1 PYQ · JEE Mains 2021

The wavelength of the photon emitted by a hydrogen atom when an electron makes a transition from n = 2 to n = 1 state is :

  1. A 194.8 nm
  2. B 490.7 nm
  3. C 913.3 nm
  4. D 121.8 nm Correct answer

Solution

$\Delta$E = 10.2 eV<br><br>${{hc} \over \lambda }$ = 10.2 eV<br><br>$\lambda$ = ${{hc} \over {(10.2)e}}$<br><br>= ${{12400} \over {10.2}}\mathop A\limits^o$<br><br>= 121.56 nm<br><br>$\simeq$ 121.8 nm

About this question

Subject: Physics · Chapter: Atoms and Nuclei · Topic: Bohr's Model of Hydrogen Atom

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