Calculate the capacitance per unit length of the cable

In summary, the conversation discusses a coaxial cable with an inner conductor diameter of 1 mm and a shield diameter of 5 mm. The task is to calculate the capacitance per unit length of the cable, given a plausible value for the dielectric constant of the material separating the two conductors. The problem is solved by assuming a charge Q and determining the potential difference across the shield. The desired range for the capacitance per unit length is given as ____ nF/m <= C/L <= _____ nF/m.
  • #1
ndoc
13
0

Homework Statement


The coaxial cable from a television or other device has an inner conductor with diameter of 1 mm and the shield of diameter 5 mm. Assume a plausible value for the dielectric constant (3 ≤ κ ≤ 5) of the dielectric separating the two conductors and calculate the capacitance per unit length of the cable.


Homework Equations


?


The Attempt at a Solution


I am really unsure of how to even start this problem. The answer they are looking for is a range ____ nF/m <= C/L <= _____ nF/m. Thanks in advance!
 
Physics news on Phys.org
  • #2
Start by assuming that one unit length of the cable has a charge Q. What would be the potential difference across the shield?
 

What is capacitance per unit length?

Capacitance per unit length is a measure of the amount of electric charge that can be stored per unit length of a cable. It is represented by the symbol C and is measured in farads per meter (F/m).

How is capacitance per unit length calculated?

Capacitance per unit length can be calculated by dividing the capacitance (C) of the cable by its length (L). The formula is C/L = C per unit length.

What factors affect the capacitance per unit length of a cable?

The capacitance per unit length of a cable is affected by the cable's geometry, dielectric material, and distance between the conductors. It is also influenced by the frequency and voltage of the electric signal passing through the cable.

Why is capacitance per unit length important?

Capacitance per unit length is important because it helps determine the amount of energy that can be stored and transferred through a cable. It is also a crucial factor in determining the overall performance and efficiency of a cable in different electrical applications.

How can capacitance per unit length be measured?

Capacitance per unit length can be measured using a capacitance meter or by using the formula C/L = C per unit length. It can also be measured indirectly by calculating the impedance of the cable and using the formula Z = 1/2πfC, where Z is the impedance, f is the frequency, and C is the capacitance per unit length.

Similar threads

  • Introductory Physics Homework Help
Replies
1
Views
1K
  • Introductory Physics Homework Help
Replies
10
Views
2K
  • Introductory Physics Homework Help
Replies
1
Views
2K
  • Introductory Physics Homework Help
Replies
1
Views
2K
  • Introductory Physics Homework Help
Replies
3
Views
12K
  • Introductory Physics Homework Help
Replies
2
Views
4K
  • Introductory Physics Homework Help
Replies
1
Views
4K
  • Introductory Physics Homework Help
Replies
11
Views
2K
  • Introductory Physics Homework Help
Replies
2
Views
6K
  • Introductory Physics Homework Help
Replies
4
Views
3K
Back
Top