Conductivity homework problem help

Click For Summary

Homework Help Overview

The discussion revolves around a problem involving the temperature dependence of resistance in a carbon resistor, specifically determining the temperature at which the resistance is 995 ohms, given its resistance at 20 degrees Celsius is 1000 ohms. The problem also asks for the conductivity at this new temperature.

Discussion Character

  • Exploratory, Assumption checking, Conceptual clarification

Approaches and Questions Raised

  • Participants discuss the need for equations relating resistivity and temperature, with one participant expressing uncertainty about how to begin solving the problem. Another participant raises concerns about the lack of instructional materials and the impact of recent changes in teaching.

Discussion Status

The discussion is ongoing, with participants exploring various aspects of the problem. Some guidance has been offered regarding the relationships between resistance, resistivity, and conductivity, although there is no explicit consensus on a method to solve the problem yet.

Contextual Notes

Participants mention constraints such as the absence of a textbook and the challenges posed by recent changes in their coursework, which may affect their understanding of the material needed to tackle the problem.

weston_sagle
Messages
5
Reaction score
0

Homework Statement


At what temperature does a carbon resistor have a resistance of 995 ohms, if it has a resistance of 1000 ohms at 20 degrees? What is its conductivity at the new temperature?


Homework Equations





The Attempt at a Solution


I don't even know where to start.
 
Physics news on Phys.org


Do you have any equations that relate the change of some property (e.g. resistivity) of a conductor with temperature changes?
 


Well, the situation isn't ideal. We recently got a new teacher, after our old teacher canceled 2 weeks of classes. Now we are trying to catch up so we have an assignment on material we haven't covered. I also have no textbook for the class. I did google searches but could only find R= conductivity*L/A but I don't have length or area.
 


Check out this link then:

http://hyperphysics.phy-astr.gsu.edu/hbase/electric/restmp.html

Then think about the connections between resistance, resistivity, and conductivity.

I don't understand why there is no text for the course. Is this a college-level course? There are many older editions of quality texts that you can get dirt cheap through Amazon.com, for example.

Also, the equation you quoted in your previous post should have "conductivity" replaced with "resistivity", according to one of my texts.
 

Similar threads

Two concentric conducting spherical shells and resistor in between
  • · Replies 44 ·
2
Replies
44
Views
5K
Underground cable with electrical short
  • · Replies 1 ·
Replies
1
Views
2K
Electric current and resistance question
  • · Replies 2 ·
Replies
2
Views
2K
The equivalent resistance for the resistors in this circuit?
  • · Replies 5 ·
Replies
5
Views
2K
Calculating total resistance of a combination circuit
  • · Replies 19 ·
Replies
19
Views
7K
Conducting rod creates a complete circuit
  • · Replies 3 ·
Replies
3
Views
1K
Ohmmeter question -- Measuring a 2-resistor circuit
  • · Replies 2 ·
Replies
2
Views
2K
Radial Heat Conduction through a Cylindrical Pipe
  • · Replies 3 ·
Replies
3
Views
2K
Measuring the resistance of a resistor
  • · Replies 1 ·
Replies
1
Views
2K
Voltage, Current, and Resistance Calculations
  • · Replies 13 ·
Replies
13
Views
2K