Question

Light has wavelength $600\, nm$ in free space. It passes into glass, which has an index of refraction of $1.50,$ What is the frequency of the light inside the glass ?

• A. $3.3 \times 10^{14} Hz$
• B. $5.0 \times 10^{14} Hz$
• C. $3.3 \times 10^{5} Hz$
• D. $5.0 \times 10^{5} Hz$

Answer 1

Answer: (B)

$5.0 \times 10^{14} Hz$

Answer 2

Given, wavelength of light $=600\, nm$ $=600\times 10^{9}\,m$ $n=1.5$ As the frequency of light cannot change, $c=v\lambda$ Speed of light in free space $=3\times10^{8}m/ s$ $\therefore 3\times10^{8}=v\times600\times10^{9}$ $\Rightarrow v=\frac{3\times10^{8}}{600\times10^{-9}}$ $=5\times10^{14}\,HZ$