# Calculation of capacitance of transmission lines

• ajith.mk91

#### ajith.mk91

Capacitance between two plates is defined as the charge accumulated per unit potential difference between those plates. But in the case of transmission lines how can we define it? The potential difference any two conductors in a group of several conductors can be derived in terms of the charges on individual wires. But how can we calculate the capacitance because there is an ambiguity in this case. The charges on both the conductors are not the same!

http://www.tup.com.cn/Resource/tsyz/030533-01.pdf [Broken]

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Well, thank you

You can look in one of those Engineering Electromagnetic Text book. They have a section on capacitance of different transmission lines like parallel plates, coax, parallel lines etc. You can study how they derive the formulas also. Good book would be "Fiend and Wave Electromagnetics" by David K Cheng.

This is too long to write it out here, it is like 5 to 6 pages of textbook.

## 1. What is capacitance and why is it important in transmission lines?

Capacitance is the ability of a material or system to store electrical charge. In transmission lines, capacitance is important because it affects the amount of energy that can be transmitted and how quickly it can be transmitted.

## 2. How is the capacitance of a transmission line calculated?

The capacitance of a transmission line can be calculated using the formula C = (ε * A)/d, where C is the capacitance in farads, ε is the permittivity of the material between the conductors, A is the cross-sectional area of the conductors, and d is the distance between the conductors.

## 3. What factors affect the capacitance of a transmission line?

The capacitance of a transmission line is affected by the distance between the conductors, the material between the conductors, and the cross-sectional area of the conductors. The shape and arrangement of the conductors can also have an impact.

## 4. How does increasing capacitance affect the performance of a transmission line?

Increasing the capacitance of a transmission line can lead to higher energy losses and slower transmission speeds. This is because a higher capacitance means more energy is needed to charge and discharge the line, and the transmission signals can become distorted.

## 5. Can the capacitance of a transmission line be reduced?

Yes, the capacitance of a transmission line can be reduced by increasing the distance between the conductors, using materials with lower permittivity, or decreasing the cross-sectional area of the conductors. However, these changes may also affect the transmission line's performance in other ways, so a balance must be struck.