Light of wavelength 589 nm in vacuum passes through a piece of fused quartz of index of refraction n = 1.458. What is the frequency of the light in fused quartz?
[Speed of light c = \(3.00×10^8 ms^{-1}\)]
A.
\(5.09×10^{15}\)Hz
B.
\(5.09×10^{14}\) Hz
C.
\(1.77×10^{15}\) Hz
D.
\(1.77×10^{14}\) Hz
Correct answer is B
n=1.458, c=\(3.00 ×10^8 ms^-1\) ,λo = 589nm; f=?
Speed of light in a medium (v)=\(\frac{c}{n}\) where n is the refractive index of the medium
⇒λn=\(\frac{589}{1.458}\) = 404nm
v=fλ
⇒f=\(\frac{v}{λ}\)
=\(\frac{2.06×10^8}{404×10^-9}\) \(1nano=10^{-9}\)
∴f=\(5.09×10^{14}\) Hz
