A layer of ethyl alcohol (n = 1.361) is on top of water (n = ...

[Collmarie]

A layer of ethyl alcohol (n = 1.361) is on top of water (n = 1.333). To the nearest degree, at what angle relative to the normal to the interface of the two liquids is light totally reflected?
 a. 78
  b. 88
  c. 68
  d. 49
  e. the critical angle is undefined

Question 2

A diver shines an underwater searchlight at the surface of a pond (n = 1.33). At what angle (relative to the surface) will the light be totally reflected?
 a. 47.3
  b. 41.2
  c. 51.1
  d. 58.7
  e. 49.8

[lorealeza77]

Answer to Question 1

A

Answer to Question 2

B