일반물리학 2 — Magnetic Fields Due to Currents: Problem 57

57 In Fig. 29-61, two circular arcs have radii \(a = 18.9\text{ cm}\) and \(b = 10.7\text{ cm}\), subtend angle \(\theta = 74.0^\circ\), carry current \(i = 0.411\text{ A}\), and share the same center of curvature \(P\). What are the (a) magnitude and (b) direction (into or out of the page) of the net magnetic field at \(P\)?