The correct answer is: C. long transmission line
Shunt capacitance is the capacitance between the conductors of a transmission line. It is usually neglected in the analysis of short transmission lines because its effect is small compared to the other line parameters, such as resistance and inductance. However, for long transmission lines, shunt capacitance can have a significant effect on the line’s performance.
In a long transmission line, the shunt capacitance can cause the line to act like a parallel resonant circuit. This can lead to a number of problems, such as voltage fluctuations and power losses. To avoid these problems, shunt capacitance is usually taken into account in the design of long transmission lines.
The following are brief explanations of each option:
- A. short transmission line
In a short transmission line, the shunt capacitance is usually neglected because its effect is small compared to the other line parameters, such as resistance and inductance.
- B. medium transmission line
In a medium transmission line, the shunt capacitance can start to have a significant effect on the line’s performance. However, it is still often neglected in the analysis of medium transmission lines.
- D. medium and long transmission lines
In a long transmission line, the shunt capacitance can have a significant effect on the line’s performance. It is usually taken into account in the design of long transmission lines.