SOLUTION

Lossless Line

In a lossless line r = g = 0. Thus we find that

${Z_c} = \sqrt {\frac{z}{y}} = \sqrt {\frac{{jwl}}{{jwc}}} = \sqrt {\frac{L}{C}} $

• For flat voltage profile system, all the voltage drop in the line are neglected therefore supply voltage (Vs) is equal to the Receiving end voltage (Vr) i.e Vs = Vr 
• The characteristic impedance of a lossless transmission line is purely real, with no reactive component.
• The energy supplied by a source at one end of such a line is transmitted through the line without being dissipated in the line itself.
• Therefore lossless line terminated with its surge impedance has Flat Voltage profile.