Answer
Given,
refractive index of film, n = 1.6
refractive index of air, n' = 1
angle of incidence, i = 35°
angle of refraction, r = ?
Using Snell's law
n' sin i = n sin r
1 x sin 35° = 1.6 x sin r
r = 21°
Angle of refraction is equal to 21°.
Now,
distance at which refractive angle comes out
d = 2.5 mm
α be the angle with horizontal surface and incident ray.
α = 90°-21° = 69°
t be the thickness of the film.
So,


t = 2.26 mm
Hence, the thickness of the film is equal to 2.26 mm.
<span>D. Along two converging oceanic plate boundaries</span>
Answer:

Explanation:
From the question we are told that
Speed of star 
Distance of spectral line 
Generally the equation for wavelength with respect to spectral lines is mathematically given by

where



therefore


Generally the equation for new wavelength is mathematically given as



Therefore
