Question

A light of wavelength $6000A^{\circ }$ in air, enters a medium with refractive index $1.5$. Inside the medium its frequency is _________ $Hz$ and its wavelength is ______ $6000A^{\circ }$.

• A. $5\times {10}^{14}Hz,4000$.
• B. $6\times {10}^{14}Hz,4000$.
• C. $5\times {10}^{14}Hz,5000$.
• D. $5\times {10}^{24}Hz,4500$.

Answer 1

Answer: (A)

$5\times {10}^{14}Hz,4000$.

$\mu =\frac{{\lambda }_{vaccum}}{{\lambda }_{medium}}1.5=\frac{6000}{\lambda }\lambda =4000\mathring{A}$

for frequency

$c=\upsilon \lambda 3\times {10}^8=\upsilon \times 6000\times {10}^{-10}$

$\upsilon =5\times {10}^{14}$Hz