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Hi Danny
My name is Julianne and i was just wondering if you could help a poor girl out with a headeache question! here goes....
What must be the radius of a circular loop of wire so the magnetic field at its center is 1.5 x 10-4 T when the loop carries a current of 15 A?
Thank you in advance Daniel
Julie
Dear Julianne,
Not that I know the answer from the top of my head, although I could have remembered it - it's one of the model problems on Biot-Savart Law. If you look at
http://hyperphysics.phy-astr.gsu.edu/hbase/magnetic/curloo.html#c2
and you'll learn that R = (M_o * I)/(2 * B) = 2 Pi * 10^(-2) meters =
= 63 millimeters
M_o ... vacuum permeability, 4 Pi * 10^(-7) T.m/A
The numerical result is rounded-up to 2 significant digits, to follow the precision of the input quantities. You can verify this number at the web page above.
Enjoy!
Daniel
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Daniel Mazur
Expertise
Questions anyone (teenager, undergrad, graduate, professional) may ask on physics, mathematics or inorganic chemistry. Questions may concern subjects themselves or a possible future career in them, if you need advice on a school or hobby project, or you just came across a question that is beyond your current curriculum. I answer bare textbook problems sometimes, but I reserve the the right to redirect you to Physics-Physics section. The kind of questions I like to answer: I just started having science classes at school and they seem difficult, but I enjoy them. Where do I find more information on this, which is not in textbooks but still comprehensible to me? Just leaving high school, and I feel science is really the thing for me. Can you recommend a school and an undergrad program suitable to my inclinations? I am in my second undergraduate year in Physics. We learned the basics of universe expanding this year, the Hubble constant and all that, but invited speakers that gave talks on astrophysics in our department seemed not to agree with this model at all. Is it of any use at all? I am building a [materials research] experimental device for my masters/doctorate thesis and I have the following problem:... I have tried ..., but it still doesn't work. Where might the problem be?
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