Calculating magnetic field given dl, current, and radius vector

AI Thread Summary
The calculation of the magnetic field involved using the cross product of dl and the radius vector, yielding a result of 0.00195i + 0.00365k. The subsequent steps included dividing by the magnitude of the radius cubed and multiplying by the current and permeability constant. However, a participant noted that the cross product appears to be off by a factor of ten, and the final answer's component ratios seem inconsistent. It was suggested to double-check the calculations and ensure proper unit usage. Accurate calculations are crucial for obtaining the correct magnetic field values.
desperatestudent123
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Homework Statement
A short current element dl = (0.500 mm)j^ carries a current of 5.70 A in the same direction as dl . Point P is located at r = ( -0.730 m)i^+ (0.390m)k^. Find the magnetic field at P produced by this current element.
Relevant Equations
dB=(u_0/4pi)*((I dl X r)/r^3)
|r|=square root ((-.73^2)+(0.39^2))
I used the above equation, and started with getting the cross product of dl and r, which was equal to 0.00195i+0.00365k. From there, I divided each component by the magnitude of radius cubed (0.827^3). I then multiplied by I and u naught(u_0=4pi*10^-7), and then divided by 4pi. The answer I got (1.96*10^-9)i + (3.67*10^-10)k. I'm not sure why this is wrong.
 
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Hello @desperatestudent123,
:welcome: ##\qquad ## !
​
The cross product seems to be off by a factor of 10 !
And how you come from 1.95 10-3 ##\hat\imath## + 3.65 10-3 ##\hat\jmath\ \ ## (ratio around 1 to 2) to the final answer (ratio 10 to 2) seems strange, too.

Funny enough, one of the components is correct :wideeyed:

In short: check your math ! And: use units !

##\ ##
 
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