Magnetism, Credit-Card magnetic strips

[Nnk]

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:

Where n=N/L

The Attempt at a Solution

Answer: 5.0µm

 

[BvU]

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) :)

 

[Nnk]

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