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 = \(3.00Ă10^8 ms^{-1}\)]
- \(5.09Ă10^{15}\)Hz
-
\(5.09Ă10^{14}\) Hz
- \(1.77Ă10^{15}\) Hz
- \(1.77Ă10^{14}\) Hz
The correct answer is: B
Explanation
n=1.458, c=\(3.00 Ă10^8 ms^-1\) ,Îťo = 589nm; f=?
Speed of light in a medium (v)=\(\frac{c}{n}\) where n is the refractive index of the medium
âÎťn=\(\frac{589}{1.458}\) = 404nm
v=fÎť
âf=\(\frac{v}{Îť}\)
=\(\frac{2.06Ă10^8}{404Ă10^-9}\) \(1nano=10^{-9}\)
â´f=\(5.09Ă10^{14}\) Hz
There is an explanation video available .