If $^{\prime} \lambda_{1}$ ' and ' $\lambda_{2}$ ' are the wavelengths of de-Broglie waves for electrons in first and second Bohr orbits in hydrogen atom, then $\left(\frac{\lambda_{1}}{\lambda_{2}}\right)$ is equal to (Energy in $1^{\text {st }}$ Bohr orbit $=-13.6 \mathrm{eV}$ )

• A

  $\frac{1}{5}$
• B

  $\frac{1}{2}$
• Correct answer
  C

  $\frac{1}{4}$
• D

  $\frac{1}{3}$

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