Ray Optics

JEE Main level, single correct, medium

105 of 295

Question 105 of 295

A ray of laser of a wavelength 630nm630nm is incident at an angle of 30∘30^{\circ} at the diamond-air interface. It is going from diamond to air. The refractive index of diamond is 2.422.42 and that of air is 11. Choose the correct option.

Show answer and solution

Answer: (C) Refraction is not possible.

sinθC=1μ=12μ2<sinθC{sin\theta }_{C}=\dfrac{1}{\mu }=\dfrac{1}{2{\mu }_{2}}\lt {sin\theta }_{C}
sinθ>sinθCsin\theta \gt {sin\theta }_{C}
θ>θC\theta \gt {\theta }_{C}
Total internal reflection will happen.

JEE Main question paper PDF

Open a shift to read the full paper on this page, or download it.

JEE Main 2025 Apr 2 Shift 1 question paper

Open Download PDF

Opening paper…

Explain it as a whiteboard videoStep-by-step, in Hinglish or English. Your first video needs no login.Solved it on paper but got it wrong?Upload a photo of your working. Mistake Doctor marks the exact line that broke.
See it move: Lens ray diagram simulationDrag the sliders and watch the numbers in this question change.Revise Ray Optics firstFormula sheet, solved examples and the traps students fall into.

More Physics practice

JEE Main Physics practice question on Ray Optics (Refraction of light from plane surface), with the answer and a step-by-step solution. Scan a question from your own book or paper to get a whiteboard video.