Answer:
The thinness of film is 116 nm.
Explanation:
Given that,
Wavelength = 650 nm
Refractive index = 1.40
We need to calculate the thickness
Using formula of thickness for destructive interference
[tex]2nt=(m+\dfrac{1}{2})\lambda[/tex]
Here, m = 0
[tex]2nt=\dfrac{1}{2}\lambda[/tex]
[tex]t = \dfrac{1}{4}\times\dfrac{650\times10^{-9}}{1.40}[/tex]
[tex]t=1.16\times10^{-7}\ m[/tex]
[tex]t = 116\ nm[/tex]
Hence, The thinness of film is 116 nm.
