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Homework Statement
Two long parallel wires are a centertocenter distance of 4.60 cm apart and carry equal antiparallel currents of 4.40 A. Find the magnetic field intensity at the point P which is equidistant from the wires. (R = 4.00 cm).
Homework Equations
magnetic field for a long straight wire = μi/2*pi*r
The Attempt at a Solution
at first i thought it was just 0 T since the current is in opposite directions but that was wrong. so i worked it out and saw that the y components cancel out and you're left with the 2 x directions components. so i thought B = [itex]\frac{2*μ*i*cos(theta)}{2*pi*r}[/itex]
where cos(theta) = R/r
where r = sqrt(R^{2}+(d/2)^{2})
this didnt work out for me. my answer was 7.1665340225x10^(4) T and it said it was wrong
B= [itex]\frac{2*4*pi*10^7*4.4*.04}{2*pi*(R^2+(d/2)^2)^(3/2)}[/itex]
anything i did wrong, plugged in wrong numbers or what?
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