Discussion Forum



1)

 A beam of light propagating at an angle $\alpha_{1}$  from a medium 1 through to another medium 2 at an angle $\alpha_{2}$. If the wavelength of light in medium 1 is $\lambda_{1}$ , then the wavelength of light in medium 2, ($\lambda_{2})$ , is 


A) $\frac{\sin \alpha_{2}}{\sin \alpha_{1}} \lambda_{1}$

B) $\frac{\sin \alpha_{2}}{\sin \alpha_{1}} \lambda_{2}$

C) $\left(\frac{ \alpha_{1}}{ \alpha_{2}}\right) \lambda_{1}$

D) $\lambda_{1}$

Answer:

Option A

Explanation:

 We know that ,

  $\lambda= \frac{\lambda_{0}}{\mu}$

 According to the question,

    $\frac{\sin \alpha_{1}}{\sin \alpha_{2}}=\frac{\mu_{2}}{\mu_{1}}=\frac{\lambda_{1}}{\lambda_{2}}$

  $\lambda_{2}=\lambda_{1}\frac{\sin \alpha_{2}}{\sin \alpha_{1}}$