The ratio of speeds of electromagnetic waves in vacuum and a medium, having dielectric constant k =3 and permeability of μ=2 μ 0 , is ( μ 0 = permeability of vacuum)

Physics · Electromagnetic Waves

JEE Main 2026 — 23 January, Evening Shift — Question 39

The ratio of speeds of electromagnetic waves in vacuum and a medium, having dielectric constant $\mathrm{k}=3$ and permeability of $\mu=2 \mu_{0}$ , is ( $\mu_{0}=$ permeability of vacuum)

Option A:
$36: 1$
Option B:
$3: 2$
Option C:
$6: 1$
Option D:
$\sqrt{6}: 1$
Correct

Answer: D

Step-by-step solution

$\frac{C}{V}=\mu=\sqrt{\varepsilon_{r} \mu_{r}}$ $\frac{C}{V}=\sqrt{\frac{3 \times 2}{1}}=\frac{\sqrt{6}}{1}$

Answer key and solution verified before publishing.

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Exam: JEE Main 2026
Paper: 23 January, Evening Shift
Subject: Physics
Chapter: Electromagnetic Waves
Topic: Power , Energy and Intensity of EM Waves