The long, thin wire shown in FIGURE 22-45 is in a region of constant magnetic field B(vector). The wire carries a current of 6.2 A and is oriented at an angle of 7.5° to the direction of the magnetic field. 

(a) If the magnetic force exerted on this wire per meter is 0.038 N, what is the magnitude of the magnetic field? 

(b) At what angle will the force exerted on the wire per meter be equal to 0.016 N?

Figure 22–45

I = 6.2 A 7.5