Light of wavelength 589 nm in vacuum passes through a pie...
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 = 3.00×108ms−1]
5.09×1015Hz
5.09×1014 Hz
1.77×1015 Hz
1.77×1014 Hz
Correct answer is B
n=1.458, c=3.00×108ms−1 ,λo = 589nm; f=?
Speed of light in a medium (v)=cn where n is the refractive index of the medium
⇒λn=5891.458 = 404nm
v=fλ
⇒f=\frac{v}{λ}
=\frac{2.06×10^8}{404×10^-9} 1nano=10^{-9}
∴f=5.09×10^{14} Hz