Answer:

Critical angle for diamond and quartz is given as

[tex]\theta_c = 37.1 degree[/tex]

Explanation:

As we know that the critical angle is the angle of incidence at which the light ray will refract at 90 degree angle

so as per law of refraction we will have

[tex]n_1 sin\theta_1 = n_2 sin\theta_2[/tex]

here we know that

[tex]n_1 = 2.42[/tex]

[tex]n_2 = 1.46[/tex]

[tex]\theta_1 = \theta_c[/tex]

[tex]\theta_2 = 90[/tex]

now we have

[tex]2.42 sin\theta_c = 1.46\times 1[/tex]

so we have

[tex]\theta_c = 37.1 degree[/tex]