Topic: Electronics Engineering
What is the characteristic impedance of a coaxial transmission line having inner conductor radius of 1 mm, outer conductor radius of 2 mm and dielectric constant of 4.0?
- A. 50 ohm
- B. 60 ohm
- C. 20.62 ohm
- D. None
Answer: C. 20.62 ohm
Explanation: Characteristic impedance of a coaxial transmission line is $Z_{0}=\frac{138}{\sqrt{k}}log(\frac{r_{1}}{r_{2}}) = \frac{138}{\sqrt{4}}log(\frac{2}{1})=20.77~\Omega$.