We know that the conductors are present in a two wire line. Dielectrics are also present between them. It is also clear that conductors can be of any length. Conductors also have some diameter. If both the length and diameter are associated with the conductor then resistance and inductance must be present there. If wires are separated from each other by placing the dielectric between them then the leakage of charge will take place, because the dielectric that we are using is an insulating material which can’t be a perfect insulator. This can be explained well by introducing the concept of shunt conductance. It is denoted by G.
All the quantities i.e. Resistance, Capacitance and Shunt conductance are calculated with respect to the length of the conductor.
The inductive resistance has a greater value than that of resistance with respect to the radio frequencies. On the other hand the value of the capacitive susceptence is also much more than that of the shunt capacitance. These all the quantities are working along the length of line. So, if we ignore both R and G then we can consider the circuit as lossless.
The circuit drawn below is formed after simplifying the circuit shown above.
