Home/
Competitive Exams/
JEE Main & Advanced/
Physics/
Ray Optics/
Question 20220
JEE Physics · Medium

Ray Optics: Critical Angle — Calculation MCQ

Solve this quality-checked JEE multiple-choice question, then review the correct answer and explanation.

Timer-based practiceDetailed answer reviewMobile-friendly flow
Critical Angle — CalculationMediumQuestion 20220

Question

Critical angle for glass (n = 1.5) to air is:
  1. A
    30°
  2. B
    42°
    Correct
  3. C
    45°
  4. D
    60°

Correct answer

42°

Explanation

sin θ_c = 1/n = 1/1.5 = 2/3 → θ_c = sin⁻¹(0.667) ≈ 41.8° ≈ 42°.

Review Ray Optics notesStart timed chapter practice