Explanation:
Given that,
Thickness = 432 nm
n = 1.38
We need to calculate the value of 2nt
For dark fringe,
[tex]2nt=m\lambda[/tex]
For bright fringe
[tex]2nt=(m+\dfrac{1}{2})\lambda[/tex]
Put the value into the formula of bright fringe
[tex]2nt=2\times1.38\times 432\times10^{-9}=1192.32\times10^{-9}[/tex]
We need to calculate the wavelength
(a). For strongly reflected
[tex]\lambda=\dfrac{2nt}{m+\dfrac{1}{2}}[/tex]
Put the value into the formula
[tex]\lambda=\dfrac{1192.32\times10^{-9}}{2+\dfrac{1}{2}}[/tex]
Here, m = 2
[tex]\lambda=4.77\times10^{-7}=477\ nm[/tex]
We need to calculate the wavelength
(b). For weakly reflected
[tex]\lambda=\dfrac{2nt}{m}[/tex]
Put the value into the formula
[tex]\lambda=\dfrac{1192.32\times10^{-9}}{2}[/tex]
Here, m = 2
[tex]\lambda=5.96\times10^{-7}=596\ nm[/tex]
Hence, This is the required solution.
