Am I on the right track with Ampere's Law?

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SUMMARY

The discussion centers on calculating the magnetic field around a current-carrying wire using Ampere's Law. The user correctly applies the integral form of Ampere's Law, ∫B·dl = µ0I, to find the magnetic field 2.0 cm away from a wire carrying a current of 3 A. The user also acknowledges that the Biot-Savart Law provides a simpler approach, yielding the same result with the formula B = µ0I / (2πr). This confirms the user's understanding of both Ampere's Law and the Biot-Savart Law in the context of long straight wires.

PREREQUISITES
  • Understanding of Ampere's Law and its integral form
  • Familiarity with the Biot-Savart Law
  • Basic knowledge of magnetic fields and current-carrying conductors
  • Ability to perform calculus-based physics calculations
NEXT STEPS
  • Study the derivation and applications of Ampere's Law in different geometries
  • Learn how to apply the Biot-Savart Law to various current configurations
  • Explore the relationship between magnetic fields and electric currents in electromagnetic theory
  • Investigate practical applications of magnetic fields in engineering and technology
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Students of physics, educators teaching electromagnetism, and professionals in electrical engineering who seek to deepen their understanding of magnetic fields generated by electric currents.

jumbogala
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Homework Statement


A wire carries a current of 3 A in the downward direction. What is the magnetic field 2.0 cm away from the wire?


Homework Equations


∫B·dl = µ0I


The Attempt at a Solution


So I pick a circle with radius 2.0 cm to go around the wire, and get

B∫dl = µ0(3 A)

∫dl evaluates to 2pi(0.02 m).

So B = [µ0(3 A) ] / 2*pi*0.02 m?
 
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That works, however the Biot-Savart law is easier to apply here and actually reduces to a formula identical to what you have written in the last line in the case of a long straight wire. B=µ0I/2(pi)r
 
Thank you! I know the Biot-Savart law also works, I just wanted to make sure my concept of Ampere's Law was correct. =)
 

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