Before light can undergo total internal reflection when incident on material 2 from material 1, what must be true of the indices of refraction?
a. n1 = n2
b. n1 < n2
c. n1 > n2
d. Either n1 or n2 must be equal to 1.
[Ques. 2] A small underwater pool light is 2.25 m below the surface of a swimming pool. What is the radius of the circle of light on the surface, from which light emerges from the water? (nwater = 1.333).
a. 3.90 m
b. 1.98 m
c. 2.55 m
d. 2.90 m
e. 1.69 m
[Ques. 3] An optical fiber is made of clear plastic with index of refraction n = 1.57 . For what angles with the surface will light remain within the plastic guide?
a. < 32.5
b. < 57.3
c. < 39.6
d. < 50.4
e. < 68.7
[Ques. 4] If total internal reflection occurs at a glass-air surface:
a. no light is transmitted.
b. no light is reflected.
c. light is leaving the air and hitting the glass with an incident angle greater than the critical angle.
d. light is leaving the air and hitting the glass with an incident angle less than the critical angle.
[Ques. 5] A fiber optic cable (n = 1.53) is submerged in water (n = 1.33). What is the critical angle for light to stay inside the cable?
a. 82.5
b. 60.4
c. 40.8
d. 48.8
e. 34.6
[Ques. 6] A ray of light travels across a liquid-to-glass interface. If the indices of refraction for the liquid and glass are, respectively, 1.63 and 1.43, what is the critical angle at this interface?
a. Critical angle does not exist.
b. 79.0
c. 61.3
d. 1.07
e. 90
[Ques. 7] Which of the following describes what will happen to a light ray incident on a glass-to-air boundary at greater than the critical angle?
a. total reflection
b. total transmission
c. partial reflection, partial transmission
d. partial reflection, total transmission
[Ques. 8] Which of the following describes what will happen to a light ray incident on an air-to-glass boundary at less than the critical angle?
a. total reflection
b. total transmission
c. partial reflection, partial transmission
d. partial reflection, total transmission
[Ques. 9] A container of flint glass (n = 1.61) holds a small quantity of benzene (n = 1.501). What is the critical angle for internal reflection of a ray in the glass when it is incident on the glass-to-liquid surface?
a. 86.1
b. 68.8
c. 41.8
d. 38.4
e. 83.9
[Ques. 10] Diamond has an index of refraction of 2.419 . What is the critical angle for internal reflection inside a diamond that is in air?
a. 24.4
b. 48.8
c. 155
d. 131
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