Magnetic field at the center of the loop

AI Thread Summary
The discussion centers on calculating the magnetic field at the center of a loop, where the original poster struggles to obtain the correct answer using standard formulas. They initially applied the formula B = I(mju_0)N/2R but received an incorrect result, leading to confusion about whether to treat the setup as a single loop or consider additional factors. A critical point raised is the necessity to account for the magnetic field contributions from both the loop and a long straight wire, emphasizing the principle of superposition. The poster expresses frustration over the lack of responses and seeks clarification on the correct approach. Ultimately, understanding the combined effects of the magnetic fields is essential for accurate calculations.
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:confused:

Here's the question:
"What is the magnetic field at the center of the loop in the figure?"

OK, the question is really simple and it looks easy. However, when I put in the answer, it's wrong. I tried different methods/formulas but still got the wrong answers. Anyone cares to enlighten me?

First, I used the formula B = I(mju_0)N/2R:
- I is 5A
- mju_0 is 4pi * 10^-7
- N is 1
- R is 0.01 m
The wrong answer was 3.14×10-4 T.

I then tried modified B = (2*10^-7)I/R (I multiplied this equation w/ some whole numbers to account for the multi directions of the field - which I then realized that it was the wrong way) I still got the wrong answers.

I then think, hell, the field might cancel out to zero, which was still wrong. (Obviously, the field was in one direction.)

PLEASE HELP. I'm desperate. :cry:
 

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Anyone? What I don't get is I cannot treat it as a single loop solenoid? If not then what method should I use?

Please help.
 
It's not just a single loop. Don't neglect the field from the long straight wire.
 
people on this board do not seem to know a lot about electromagnetic. I posted two questions and so far no replies yet.
 
Doc Al provided an answer. We expect students to do their homework.

The key is superposition of two magnetic fields due to the long straight wire and the loop.

Meanwhile, we'll take a look at the other questions.
 
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