Magnetism, Credit-Card magnetic strips

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SUMMARY

The discussion centers on the magnetic field strength required to corrupt the information on a credit card's magnetic strip, established at 1000 gauss based on experiments from the television show Mythbusters. A problem is presented involving a straight wire carrying a current of 2.5 A, with the goal of determining the safe distance a credit card can be held from the wire without damage. The correct approach to solving this problem involves using the formula for the magnetic field around a straight conductor, rather than the equation for a solenoid. The calculated safe distance is 5.0 µm.

PREREQUISITES
  • Understanding of magnetic fields and their measurements (gauss)
  • Knowledge of current-carrying conductors and their magnetic effects
  • Familiarity with relevant equations for magnetic fields around straight wires
  • Basic algebra for solving physics problems
NEXT STEPS
  • Study the formula for the magnetic field around a straight wire: B = (μ₀/2π) * (I/r)
  • Learn about the effects of magnetic fields on electronic devices and data storage
  • Explore the principles of magnetism in physics, including magnetic field strength and distance
  • Investigate real-world applications of magnetic fields in technology and security systems
USEFUL FOR

Students studying physics, electrical engineers, and anyone interested in the effects of magnetic fields on electronic devices, particularly in relation to credit card technology.

Nnk
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Homework Statement


Experiments carried out on the television show Mythbusters determined that a magnetic field of 1000 gauss is needed to corrupt the information on a credit card's magnetic strip. (They also busted the myth that a credit card can be demagnetized by an electric eel or an eelskin wallet.) Suppose a long, straight wire carries a current of 2.5 A. How close can a credit card be held to this wire without damaging its magnetic strip?

I'm not quite sure how to go about this problem, could anyone please explain it?

Homework Equations


Magnetic field of a solenoid:
upload_2014-12-12_16-59-23.png

Where n=N/L

The Attempt at a Solution


Answer: 5.0µm
 
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Hi Nn,

Your relevant equation isn't for a simple straight wire. Look e.g. here

Oh, and: next time use the template as it's intended (I.e. show some work under 3, not the answer from the back of the book) :)
 
BvU said:
Hi Nn,

Your relevant equation isn't for a simple straight wire. Look e.g. here

Oh, and: next time use the template as it's intended (I.e. show some work under 3, not the answer from the back of the book) :)

Thanks for pointing that out! I didn't know how to calculate it, so I put the correct answer there for those who could help
 

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