Question

A light ray in a medium (RI = 5/3) enters another medium at an angle of 30°. The angle in the other medium is sin^-1 (5/6). The incident angle must be increased such that the ray is completely reflected at minimum degrees is ______.

Options

• 5.00

• 6.00

• 7.00

• 8.00

Answer 1

A light ray in a medium (RI = 5/3) enters another medium at an angle of 30°. The angle in the other medium is sin^-1 (5/6). The incident angle must be increased such that the ray is completely reflected at a minimum degree is 7.00.

Explanation:

`5/3 sin30^circ = n. 5/6` ⇒ n = 1

sinθc = `3/5` ⇒ θc = 37°

and so 37 - 30 = 7