Index of refraction?
1.) In this question, you will examine how light is refracted as it passes into a fish tank filled with water.
A large fish tank is filled with water (of refractive index 1.33). One side of the tank is made of a parallel-sided piece of glass. A ray of light strikes the glass from the outside at an angle of incidence of 43°.
Estimate the angle through which this ray is deviated as it emerges into the water. Just give the magnitude of the deviation, there's no need for signs.
1.) In this question, you will examine how light is refracted as it passes into a fish tank filled with water.
A large fish tank is filled with water (of refractive index 1.33). One side of the tank is made of a parallel-sided piece of glass. A ray of light strikes the glass from the outside at an angle of incidence of 43°.
Estimate the angle through which this ray is deviated as it emerges into the water. Just give the magnitude of the deviation, there's no need for signs.
1 Answer
The ray of light suffers two refractions as it enters from air to glass and then when it enters water from glass. Assuming refractive index of glass
- First refraction at air-glass interface. Applying Snell's Law
#n_asin i=n_gsinr#
#=>1.0sin43^@=1.5sinr^@#
#=>r=arcsin(sin43^@/1.5)#
#=>r=27.04^@# - This angle becomes angle of incidence for the glass-water interface. Applying Snell's Law
#n_gsin i_g=n_wsinr_w#
#=>1.5sin 27.04^@=1.33sinr_w#
#=>r_w=arcsin(1.5/1.33sin 27.04^@)#
#=>r_w=30.85^@#
Magnitude of angle of deviation as the ray emerges in water
#=43-30.85=12.15^@#
