What is the field strength and when does a situation like this occur?

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SUMMARY

The field strength required to achieve a current density of 5 x 10-4 A/m2 in a conductor with a resistivity of 5 x 10-8 Ω m is calculated to be 2.5 x 10-3 N/C. This is derived using the equation J = σE, where J is the current density and σ is the conductivity. The discussion also highlights practical scenarios, such as running 100 amps through a conductor measuring 0.01 m by 0.01 m, resulting in a resistance of 5 x 10-4 ohms per meter and a voltage drop of 0.05 volts per meter, leading to a power dissipation of 5 watts per meter.

PREREQUISITES
  • Understanding of Ohm's Law and its applications
  • Familiarity with the concepts of current density and resistivity
  • Knowledge of basic electrical units (volts, amperes, ohms)
  • Proficiency in using the equation J = σE for electrical calculations
NEXT STEPS
  • Research the properties of conductors, specifically focusing on resistivity and conductivity
  • Learn about the implications of current density in electrical engineering applications
  • Explore the relationship between voltage, current, and resistance in practical circuits
  • Investigate power dissipation in electrical conductors and its impact on system design
USEFUL FOR

Electrical engineers, physics students, and professionals involved in circuit design and analysis will benefit from this discussion, particularly those focusing on current density and resistivity in conductors.

aps0324
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Please help me with the following:

What is the field strength needed to achieve a current density of 5 x10^4 [Am^-2] in a conductor of resistivity 5 x 10^-8 [Ω m]

The answer I got was 2.5 x 10^-3 N C^-1

using the equation J = σ E

But then I was wondering when a situation like this occurs and this i do not know.

Thank you for any help
 
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Thank you for using mks units. because an ohm is one volt per amp, we can multiply 50,000 amps per square meter and 5 x 10^-8 ohm meters (pure copper is 1.72 x 10^-8) and get 0.0025 volts per meter. Suppose 100 amps is run in a conductor 0.01 m by 0.01 m. The resistance would be 5 x 10^-4 ohms per meter. The voltage drop would be 0.05 volts per meter, and the power dissipation would be 5 watts per meter.
 

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