Topic: Electromagnetics
The intrinsic impedance of free space is 377 $\Omega$. The approximate intrinsic impedance of a medium with relative permittivity and permeability of 4 and 1 respectively will be
- A. 75 $\Omega$
- B. 94 $\Omega$
- C. 188 $\Omega$
- D. 377 $\Omega$
Answer: C. 188 $\Omega$
Explanation: $\eta=\sqrt{\frac{\mu_{0}}{\epsilon_{0}}}\cdot\sqrt{\frac{\mu_{r}}{\epsilon_{r}}}=377\cdot\sqrt{\frac{1}{4}}=188~\Omega$