COMEDK · Physics · 24. Electromagnetic Waves
Speed of electromagnetic wave in a medium having relative permittivity \(\varepsilon_r\) and relative permeability \(\mu_r\) is (speed of light in air, \(\left.c=3 \times 10^8 \mathrm{~m} / \mathrm{s}\right)\)
- A \(\dfrac{1}{\sqrt{\mu_r \varepsilon_r}}\)
- B \(\dfrac{c}{\sqrt{\mu_r \varepsilon_r}}\)
- C \(c \sqrt{\dfrac{\mu_r}{\varepsilon_r}}\)
- D \(\dfrac{c}{\mu_r \varepsilon_r}\)
Answer & Solution
Correct Answer
(B) \(\dfrac{c}{\sqrt{\mu_r \varepsilon_r}}\)
Step-by-step Solution
Detailed explanation
The speed of an electromagnetic wave in a vacuum is given by \(c = \dfrac{1}{\sqrt{\mu_0 \varepsilon_0}}\). The speed of an electromagnetic wave in a medium with absolute permittivity \(\varepsilon\) and absolute permeability \(\mu\) is given by…
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