Question

A soap film of 5x107 m thick is viewed at an angle of 35° to the
normal. Find the wavelengths of light in the visible spectrum which
will bw absent from the reflected light, given that the refractive index
of the film is 1.33.​

Answer 1

Answer:

not sure about my answer

Explanation:

so l am not giving answer

Answer 2

μ= 1.33, t = 6 x 10−5 cm, i=35°

μ=sin isin rsin r=sin iμ=0.43

Therefore, r = 25.46

cos r = 0.902

Condition for darkness is 2μ t cos r = nλ

Substitute values of n as 1,2,3,4……… we will get corresponding wavelengths .those wavelengths which fall in the visible spectra will remain absent.

For n=1, λ1=2×1.33×6×10−5×0.902=14395AUn=2, λ2=2×1.33×6×10−5×0.9022=7197AUn=3, λ3=2×1.33×6×10−5×0.9023=4798AUn=4, λ4=3598AUn=5, λ5=2879AU