Answer:
Wavelength is calculated as 213.9 nm
Solution:
As per the question:
Wavelength of light = 570 nm
Time, t = 16.5 ns
Thickness of glass slab, d = 0.865 ns
Time taken to travel from laser to the photocell, t' = 21.3
Speed of light in vacuum, c =
Now,
To calculate the wavelength of light inside the glass:
After the insertion of the glass slab into the beam, the extra time taken by light to cover a thickness t = 0.865 m is:
t' - t = 21.3 - 16.5 = 4.8 ns
Thus
where
n = refractive index of the medium
v = speed of light in medium
n = 2.66
Now,
The wavelength in the glass: