Alayer of oil (n = 1.38) floats on an unknown liquid. a ray of light originates in the oil and passes into the unknown liquid. the angle of incidence is 65.0°, and the angle of refraction is 53.0°. what is the index of refraction of the unknown liquid?

Refractive index of unknown liquid = 1.56

Explanation:

Using Snell's law as:

Where,  

 is the angle of incidence  ( 65.0° )

is the angle of refraction  ( 53.0° )

is the refractive index of the refraction medium  (unknown liquid, n=?)

is the refractive index of the incidence medium (oil, n=1.38)

Hence,  

Solving for ,

Refractive index of unknown liquid = 1.56

t = 1/400 h   ⇔ 0.0025 h ⇔ 9s ⇔ 0.15 m

any of the answers are correct.