A distortionless line is one in which the attenuation constant α is frequency independent while the phase constant β is linearly dependent on frequency.

What is the necessary condition for Distortionless transmission line?

Explanation: For a distortionless line, the condition R/L = G/C must be true. On substituting for R = 20, L = 40 mH, C = 40 μF, G = 0.02, we get R/L = 500 and G/C = 500. Thus the line is distortionless.

Are telephone lines Distortionless?

A lossless line is also a distortionless line, but a distortionless line is not necessarily lossless. lossless lines are desirable in power transmission, telephone lines are required to be distortionless.