Question

A lossless line will be distortionless if the phase shift

• A. is constant with frequency
• B. varies directly with frequency
• C. has nothing to do with distortion on a lossless line
• D. varies inversely with frequency

Hint:

Distortionless ⇒ linear phase response.

Answer 1

The Correct Option is B

Concept: For distortionless transmission: \[ \beta \propto \omega \]

Step 1: Define phase constant \[ \beta = \text{phase shift per unit length} \]

Step 2: Condition for no distortion Phase shift must vary linearly with frequency.

Step 3: Lossless line No attenuation but phase variation matters.

Step 4: Requirement \[ \beta = k\omega \]

Step 5: Conclusion \[ \boxed{\text{Varies directly with frequency}} \]