The wavelength of light emitted from second orbit to first orbits in a hydrogen atom is
Answer & explanation
Correct answer: option 1
Energy radiated $E=10.2 ~eV=10.2 \times 1.6 \times 10^{-19}$ J
$\Rightarrow E=\frac{h c}{\lambda} \Rightarrow \lambda=1.215 \times 10^{-7}$ m