Refraction

Step 1: Understanding the prism formula.
For an equilateral prism, the angle of the prism . The minimum angle of deviation for a prism is
given by the relation:
where is the refractive index of the material of the prism.
Step 2: Substituting the values.
Given that the refractive index , we substitute into the formula:
Solving this expression gives . Thus, the correct answer is
(B) 30°
.