3. A) A conducting wire carrying a current I - 4.00 A is bent into the shape shown in Figure 3 If arc B has a radius of 7.00 cm and arc D has a radius of 10.0 cm, what is the magnitude and direction of the magnetic field at the center O? D 90 Figure 3. 3. B) A conductor is bent in as shown in Figure 4. Sections A and Care semi-infinite. If the current I= 20.0A and d = 5.00 cm, what is the magnitude and direction of the magnetic field at P? You must give the magnetic field contribution from each section to receive full credit. A P d B C