A transmission line having a length of more than 80 kms but less than 250 kms is considered as a medium transmission line. The parameters (Resistance, Inductance, and Capacitance) are distributed uniformly along the line. For a medium transmission line, charging current is appreciable and due to the length of the line the shunt admittance plays a significant role in the calculation of the effective parameters of the line.
The shunt admittance and series impedance are considered as a lumped parameter of the medium transmission line. The medium transmission line is shown below in the diagram.