Question

In the absence of attenuation on the line \( (\alpha = 0) \), the Voltage Standing Wave Ratio (VSWR) is

• A. The same everywhere on a uniform, source free section of line
• B. Infinity on a uniform, source free section of line
• C. Zero on a uniform, source free section of line
• D. -1 on a uniform, source free section of line

Hint:

VSWR is a measure of signal reflection and its value becomes infinity when there is no attenuation and when the line is terminated in either open or short circuit.

Answer 1

The Correct Option is B

The Voltage Standing Wave Ratio (VSWR) is a measure of impedance mismatch on a transmission line. The formula for VSWR is: \[ VSWR = \frac{1 + |\Gamma|}{1 - |\Gamma|} \] where \(\Gamma\) is the reflection coefficient. When there is no attenuation \((\alpha = 0)\), and if the line is terminated at either open circuit or short circuit, the magnitude of the reflection coefficient \( |\Gamma| \) is 1, leading to VSWR= infinite.