Question

1. When light propagates from a material with a given index of refraction into a material with a smaller index of refraction, the speed of the light
A) incease
B) decrease
C) remain constant

2. What is the minimum value that the index of refraction can have?
A) 0
B) +1
C) -1
D)between zero and 1

3) Now consider a ray of light that propagates from water (n=1.33) to air (n=1). If the incident ray strikes the water-air interface at an angle angle one does not = zero , which of the following relations regarding the angle of refraction,angle 2 , is correct?
A) angle two > angle one
B) angle two < angle one
C) angle two = angle one

Answer 1

The refractive index is the ratio between velocity in air and velocity in medium. Here, velocity v and the refractive index n are inversely proportional to each other. So, if the velocity is small then the refractive index is increases ANS: A The minimum refractive index is one. The light cannot travel faster through the medium. ANS: B) +1 From the equation of refractive index, n, sin e, -n2 sin 62 n sin 6 n, sin 6

Here, and n, are refractive indexes. From the given data. n >n So, from the above equation the angles are, ANS: A) Angle 2 > Angle 1