Topic: Electromagnetics
For a plane travelling EM wave, the correct equation for characteristic impedance Z for the medium with permittivity of $\epsilon$ and permeability of $\mu$ is
- A. $Z=\sqrt{\frac{\mu}{\epsilon}}$
- B. $Z=\sqrt{\frac{\epsilon}{\mu}}$
- C. $Z=\sqrt{(\mu\times\epsilon)}$
- D. $Z=\frac{1}{\sqrt{\mu\times\epsilon}}$
Answer: A. $Z=\sqrt{\frac{\mu}{\epsilon}}$
Explanation: $Z=\sqrt{\frac{j\omega\mu}{\sigma+j\omega\epsilon}} \rightarrow$ Intrinsic impedance in conducting medium. Now suppose $\sigma=0$ (for lossless or perfectly dielectric medium) $Z=\sqrt{\frac{\mu}{\epsilon}}$.