What Do p and l Represent in the Resistance Formula R = pl/A?

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Homework Help Overview

The discussion revolves around the resistance formula R = pl/A, specifically focusing on the meanings of the variables p and l within the context of electrical resistance and material properties.

Discussion Character

  • Conceptual clarification, Assumption checking

Approaches and Questions Raised

  • Participants explore the definitions of p (resistivity) and l (length) and question how to handle unit conversions when applying the formula to different distances.

Discussion Status

Some participants have provided clarifications regarding the meanings of the variables, while others are questioning the implications of using different units for length and resistivity. The conversation is ongoing with various interpretations being explored.

Contextual Notes

There is mention of specific unit considerations, such as using centimeters for length when resistivity is expressed in ohm.cm, and the need to convert distances into meters for calculations.

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R= pl/A
what does p and l stands for?
 
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p is the resistivity of a material(ohms.cm). Every material normally has a set value for it. l is the length of the material.
 
thank you
But if i had a distance of 100 km ,do i replace "l" with d and convert it to metres?
 
from my experience with this equation(electronic subject) we had "l" in cm, but that was because we had "p" in ohm.cm for example

R = pl/A ----> ohms = [(ohms.cm)(cm)]/cm(^2)
 

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