A transmission line designed for power transmission at 60 Hz

A transmission line designed for power transmission at 60 Hz is made with superconducting cables. The two conductors that make the transmission line are separated by 3 m. The sizes of the wires are not known, but their inductance per unit length is known to be 0.5 microH/m. The permittivity and the permeability are those of free space and the conductivity of air is 10^-7 S/m. Calculate a) The attenuation constant on the line, b) the characteristic impedance of the line.

6) A transmission line designed for power transmission at 60 Hz is made with superconducting cables The two conductors that make the transmission line are separated by 3 m. The sizes of the wires are not known, but their inductance per unit length is known to be 0.5 microH/m. The permittivity and the permeability are those of free space and the conductivity of air is 10- S/m. Calculate a) The attenuation constant on the line, b) the characteristic impedance of the line. eif 1

Solution

L= inductance=0.5 micro H

d = 3m , permiablity= 4**10^-7

€= permittivity=8.85*10^-12

W= Length of transmission line=4**10^-7*d/L

=7.5 m

C= capacitance=€*w/d=8.85*10^-12*7.5/3=22.1 pf

Zo= characteristic impedance=(L/C)

=(0.5*10^6/22.1)^0.5

=150

Attenuation conatant=G*Zo/2=10^-7*150/2=75*10^-6