A layer of liquid B floats on liquid A. A ray of light begins in liquid A and undergoes total internal reflection at the interface between the liquids when the angle of incidence exceeds 38.0°. When liquid B is replaced with liquid C, total internal reflection occurs for angles of incidence greater than 49.5°. Find the ratio nB/nC of the refractive indices of liquids B and C. nB/nC =?

Respuesta :

Answer:

The ratio of the refractive indices of the liquids is 1.22

Solution:

Critical angle for A and B interface, [tex]\theta_{AB} = 38.0^{\circ}[/tex]

Critical angle for A and B interface, [tex]\theta_{AC} = 49.5^{\circ}[/tex]

Now,

From the relation in between the critical angle and refractive index:

[tex]n = \frac{1}{\theta_{c}}[/tex]              (1)

where

n = rafractive index

[tex]\theta_{c}[/tex] = critical angle

Thus

For AB interface:

[tex]n_{B} = \frac{1}{sin\theta_{AB}} = \frac{1}{sin(38.0^{\circ})} = 1.606[/tex]

For AC interface:

[tex]n_{C} = \frac{1}{sin\theta_{AC}} = \frac{1}{sin(49.5^{\circ})} = 1.315[/tex]

Thus the ratio of the refractive indices of these liquids can be given as:

[tex]\frac{n_{B}}{n_{C}} = \frac{1.606}{1.315}[/tex]

[tex]\frac{n_{B}}{n_{C}} = 1.22[/tex]

Q&A Education