What is the relationship between heat loss and resistivity in a cable?

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SUMMARY

The relationship between heat loss and resistivity in a cable is fundamentally governed by the equation R = ρ * l / A, where R represents resistance, ρ is resistivity, l is the length of the conductor, and A is the cross-sectional area. In this context, longer cables exhibit higher resistance, leading to increased heat loss due to the formula P = I^2R. The discussion concludes that cable B, with higher resistivity, was initially thought to be the correct answer, but the length of the cable plays a crucial role in determining overall resistance and heat loss.

PREREQUISITES
  • Understanding of electrical resistance and Ohm's Law
  • Familiarity with the concepts of resistivity and its units
  • Knowledge of the relationship between current, voltage, and power
  • Basic grasp of geometric properties of conductors, such as length and cross-sectional area
NEXT STEPS
  • Study the implications of resistivity in different materials for electrical applications
  • Learn about thermal management techniques in electrical systems
  • Explore the impact of cable length on electrical efficiency and heat generation
  • Investigate the use of simulation tools for analyzing heat loss in electrical circuits
USEFUL FOR

Electrical engineers, physics students, and anyone involved in the design and analysis of electrical systems, particularly those focused on minimizing heat loss in cables.

dinhjeffrey
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Homework Statement



http://img710.imageshack.us/i/2631001.jpg/
#29

Homework Equations



p=I^2R
P=IV

The Attempt at a Solution


well, the answer is D, but i don't see why the length matters? can anyone find out the equation for this problem?
i thought it was B) cable B because it has more resistivity
 
Physics news on Phys.org
The resistance of a conductor can be found using the equation,

R = p*l/A

where R = resistance, p = resistivity, l = length of conductor, and A =cross sectional area of conductor.

Length matters because the longer a resistor is, the more it can obstruct the flow of charge.
 

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