Ray Optics

JEE Main level, single correct, medium

63 of 295

Question 63 of 295

The critical angle of a medium for a specific wavelength, if the medium has relative permittivity 33 and relative permeability 43\dfrac{4}{3} for this wavelength, will be:

Show answer and solution

Answer: (B) 30o{30}^{o}

V=1μϵV=\dfrac{1}{\sqrt{\mu \epsilon }}
n=μrϵr=2n=\sqrt{{\mu }_{r}{\epsilon }_{r}}=2
sinic=1n=12sin{i}_{c}=\dfrac{1}{n}=\dfrac{1}{2}
ic=30∘{i}_{c}=30^{\circ}

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 (Critical angle and total internal reflection), with the answer and a step-by-step solution. Scan a question from your own book or paper to get a whiteboard video.