The figure below illustrates a single wire carrying a current I. The wire is either pointing directly at the point P, or it is bent into a circular arc centered on point P. The angle which the circular arc forms is θ. The entire setup is lying in a plane, and the radius of curvature of the circular part is R. (a) Convince me that the straight portions of the circuit do not contribute to the magnetic field at point P. (b) Determine the magnetic field at P