Physics 2009 JAMB Past Questions - Question 34: If the refractive index of crown glass is 1.51, its critical angle is

Correct Answer

C

Explanation

The critical angle (θc) of a medium, in this case, crown glass, can be calculated using the formula:

θc = arcsin(1 / n)

Where:
θc = critical angle
n = refractive index of the medium

In this case, the refractive index (n) of crown glass is given as 1.51. Now, you can calculate the critical angle:

θc = arcsin(1 / 1.51)

θc ≈ arcsin(0.6623)

Using a calculator or a trigonometric table, you can find the inverse sine (arcsin) of 0.6623:

θc ≈ 41.4 degrees

So, the critical angle of crown glass with a refractive index of 1.51 is approximately 41.4 degrees.