A. A conduit consists of a circular R-loop and two straight sections as shown in the figure below. The conductor is at the level of the page and diffused by current I. Find the magnetic field in the center of the circular loop.
B. Consider the loop of the following scheme.It is leaked by a current of intensity I and consists of ray arrows a, b and linear radial portions centered on point P. Calculate the magnitude and direction of the magnetic field at point P.