Resistance Between Terminals AC and AD

  • Thread starter Thread starter shimizua
  • Start date Start date
  • Tags Tags
    Ac Resistance
Click For Summary
SUMMARY

The resistance between terminals AC and AD in an underground telephone cable can be determined using the formula R = ρL/A, where ρ is the resistivity, L is the length, and A is the cross-sectional area. A technician measures the resistance between terminals AB as RAB and between terminals CD as RCD to locate a short circuit at point P. The resistance expressions can be derived based on the distance x from terminal A to the short circuit, leading to RAB = ρx/A and RCD = ρ(L - x)/A. These relationships allow for the calculation of resistances across different segments of the cable.

PREREQUISITES
  • Understanding of electrical resistance and the formula R = ρL/A
  • Familiarity with resistivity (ρ) and its role in calculating resistance
  • Basic knowledge of circuit analysis and measurement techniques
  • Concept of short circuits and their implications in electrical systems
NEXT STEPS
  • Study the principles of resistivity and its impact on different materials
  • Learn about circuit analysis techniques for locating faults in wiring
  • Explore methods for measuring resistance in practical applications
  • Investigate the effects of temperature on resistivity and resistance calculations
USEFUL FOR

Electrical engineers, technicians involved in telecommunications, and students studying circuit analysis will benefit from this discussion on measuring resistance in underground telephone cables.

shimizua
Messages
99
Reaction score
0

Homework Statement


What is the resistance between terminals AC? What is the resistance between AD?

An underground telephone cable, consisting of a pair of wires, has suffered a short
somewhere along its length (at point P in the Figure). The telephone cable is L long,
and to determine where the short is, a technician first measures the resistance between
terminals AB to be RAB; then he measures the resistance across the terminals CD to be
RCD.

http://capa-new.colorado.edu/teacher/capalibrary/Graphics/Gtype58/prob08.gif



Homework Equations


So I know that to find resistance we do R=pl/A but I don't really know how I would find it in this situation since it is not like finding AB or CD like I have done before. Please help



The Attempt at a Solution


Not sure if I would just kinda do something like
R(ac)=pL/A ? and just have it be that simple and then
R(ad)=pL/A + R(cd) ? please help
 
Physics news on Phys.org
Say x is the distance from A to the short. Can you write an expression for the resistance RAB in terms of x? How about an expression for RCD in terms of x?
 

Similar threads

Finding the Resistance of a Fault in a Pair of Transmission Lines
  • · Replies 8 ·
Replies
8
Views
2K
What is the Resistance of a Loop in the Presence of Motional EMF and Gravity?
  • · Replies 9 ·
Replies
9
Views
2K
Underground cable with electrical short
  • · Replies 1 ·
Replies
1
Views
1K
Ratio of the length of resistive wires in a square
  • · Replies 4 ·
Replies
4
Views
2K
Short in Wires with 2 Different Resistances
  • · Replies 7 ·
Replies
7
Views
6K
How Do You Calculate the Location of a Short in an Underground Cable?
  • · Replies 3 ·
Replies
3
Views
5K
Determining resistance for unknown circuit
  • · Replies 8 ·
Replies
8
Views
2K
What Is the Angle Between Position Vectors AB and AC?
  • · Replies 7 ·
Replies
7
Views
2K
A problem with equivalent resistance
  • · Replies 1 ·
Replies
1
Views
1K
The phase difference between current and voltage.
  • · Replies 30 ·
2
Replies
30
Views
5K