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For 11 kV line, inductance per kilometer per phase will be of the order of
1 H
0.1 H
1 mH
0.1 mH
1 mH
For overhead transmission lines, the loop inductance per phase per kilometer typically falls in the range of 1 mH to $1.5$ mH ┬╖ This value is relatively consistent across common distribution voltage levels like 11 kV because the geometric mean distance (GMD) and geometric mean radius (GMR) of standard conductors do not vary by orders of magnitude for typical spacing.
For overhead transmission lines, the loop inductance per phase per kilometer typically falls in the range of 1 mH to $1.5$ mH ┬╖ This value is relatively consistent across common distribution voltage levels like 11 kV because the geometric mean distance (GMD) and geometric mean radius (GMR) of standard conductors do not vary by orders of magnitude for typical spacing.
L=2├Ч10тИТ7ln(GMRGMDтАЛ)┬аH/m тАФ Inductance of a single phase transmission line
GMD=3DabтАЛDbcтАЛDcaтАЛтАЛ тАФ Geometric Mean Distance for three-phase spacing
The inductance of a transmission line is governed by the flux linkages per unit current ┬╖ It depends on the internal flux linkage of the conductor and the external flux linkage determined by the distance between conductors ┬╖ Since L=2├Ч10тИТ7ln(GMRGMDтАЛ) H/m, for standard conductor configurations, the resulting value is approximately 1┬аmH/km.
Inductance of transmission lines is primarily determined by conductor geometry and spacing.
The 11 kV voltage level does not significantly alter the inductance value; it remains a property of the line configuration.
The range of 1-1.5 mH/km is a standard rule of thumb used in power system calculations.
Simplifies rapid estimation for short-line distribution calculations.
Provides a baseline for assessing inductive reactance XLтАЛ=2╧АfL.
Neglects the impact of bundled conductors which would reduce the effective inductance.
Assumes standard symmetrical spacing.
Distribution system modeling.
Voltage drop calculations in rural and urban 11 kV feeders.
Option A (1 H) is physically impossible for a 1 km segment as it would lead to extreme impedance.
Option D (0.1 mH) is too low for standard overhead conductor spacing.
Transmission line inductance is independent of operating voltage but is influenced by the physical geometry.
C is correct тАФ For a typical 11 kV overhead line, the inductance per phase per kilometer is approximately 1 mH.
Remember that inductance per kilometer is effectively constant for overhead lines regardless of voltage; focus on the spacing (GMD) if you need a precise calculation.