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Treefrog
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Homework Statement
Long wire is bent such that it forms two parallel line segments that goes to -∞ along the z-axis and a semicircle of radius (R). Find magnetic field on Z axis.
Homework Equations
Biot-Savart Law
(μ0/4π) I = ∫ dl' x R/ R^2
where dl' is element of length and R is the unit vector, and R is the vector from source to point on z-axis
The Attempt at a Solution
So my attempt. I broke the problem into two parts. Magnetic field due to semicircle and magnetic field due to infinite wires.
For the infinite wires I got
B= μ0 I/2πR
which I'm pretty sure is correct.
The problem I'm having is calculating the magnetic field due to the semicircle
dl' = Rdθ [sinθ, 0, cosθ]
R = [Rcosθ, 0, Rsinθ+z]
R^2= (Rcosθ)^2 + (Rsinθ+z)^2
(dl' x R) = R^2+Rzsinθ dθ
B = μ0/4π ∫ {(R^2+Rzsinθ)/(Rcosθ)^2 + (Rsinθ+z)^2 } dθ
I feel like a made mistake somewhere.
Since if z=0
magnetic field due to the semicircle should be
B = μ0*I/2R
but that's not what my answer is showing.
Any help would greatly appreciated.
thanks