Magnetic Field in a Cylindrical Conductor

AI Thread Summary
A cylindrical conductor with a radius of 2.49 cm carries a current of 2.17 A uniformly distributed across its cross-section. The initial attempt to calculate the magnetic field using the equation B = µI / 2πr was incorrect. The correct formula for the magnetic field inside the conductor is B = µIr / 2πa^2. Using this formula, the magnetic field at r = R/2 was calculated to be 8.71e-6 T. This clarification is useful for anyone facing similar issues in magnetic field calculations within conductors.
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Homework Statement



A cylindrical conductor of radius R = 2.49 cm carries a current of I = 2.17 A along its length; this current is uniformly distributed throughout the cross-section of the conductor. Calculate the magnetic field midway along the radius of the wire (that is, at r = R/2).

Radius (m) = 2.49 cm = 0.0249 m = 0.01245 m (as asked)
Current (I) = 2.17 A


Homework Equations



I thought it was B = µI / 2πr because i was given a sheet of equations and this was the only one that seemed to fit it.


The Attempt at a Solution



B = µI / 2πr
B = (4π x 10^-7)(2.17) / 2π(0.01245)
B = 3.49e-5 T

Though this isn't the right answer. Not sure what's gone wrong here.
I also thought it was zero since it's a "conductor" also not right...
 
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Not to worry, i got the answer. I was using the wrong equation.
For values of Magnetic Field inside the given radius the equation is

B = µIr / 2πa^2
B = (4π x 10^-7)(2.17)(0.01245) / 2π(0.0249^2)
B = 8.71e-6 T

In case anyone else had the same or similar problems.
 
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