An electromagnetic wave of frequency 5 GHz, is travelling in a medium whose relative electric permittivity and relative magnetic permeability both…
JEE Main 2021 — Physics Electromagnetism
2021integerhard
An electromagnetic wave of frequency 5GHz, is travelling in a medium whose relative electric permittivity and relative magnetic permeability both are 2. Its velocity in this medium is _______×107ms−1.
Official previous-year question
Held on 24 Feb 2021 · Verified 6 Jul 2026.
Did you get this right?
Sign in to track your attempts and accuracy.
Solution
Given : Frequency of wave f=5GHz
=5×109Hz
Relative permittivity, ϵr=2 and Relative permeability, μr=2 Since speed of light in a medium is given by,
v=μ∈1=μrμ0⋅ϵr∈01
v=μrϵf1μ0ϵ01=μrϵrC
Where C is speed of light is vacuum
∴v=43×108=230×107ms−1
=15×107ms−1
∴ Ans. is 15
Your note
Sign in to keep a private note on this question. Nothing you write is ever public.