Question

The refractive index of a material is 1.5. The angle of incidence for which the angle of refraction is 30° is:

• A. 45°
• B. 60°
• C. 30°
• D. 15°

Hint:

Snell's law relates the angles of incidence and refraction with the refractive index of the medium. Use it to calculate the missing angle when refractive index is known.

Answer 1

The Correct Option is B

Step 1: Use Snell's law. Snell's law gives the relation between the angles and refractive index: \[ \sin(i) = n \sin(r) \] Where \( i \) is the angle of incidence, \( n \) is the refractive index, and \( r \) is the angle of refraction.
Step 2: Apply Snell's law with \( n = 1.5 \) and \( r = 30^\circ \): \[ \sin(i) = 1.5 \sin(30^\circ) \] Solving gives \( i = 60^\circ \).