1. The problem statement, all variables and given/known data "The toroid shown in the figure has a wire carrying a current I= 7.80 Amperes wrapped around it N= 920 times. The inner radius is R1 14.0 cm and outer radius R2 16.8cm. What is the magnitude of the magnetic field along a circle that is halfway between the inner and outer edges of the toroid?" 2. Relevant equations Magnetic field of a Toroid: B=μ0NI/2πr B=magnetic field μ0=permeability constant=4πx10-7 N/A2 N=number of times the wire is wrapped around the toroid I=current r=radius 3. The attempt at a solution Since the problem is asking for the field in the middle of the toroid, I decided to set my radius to halfway between the outside and inside: 16.8 cm-14 cm=2.8 cm r=14+2.8 cm=.168 m When I plug in this and all the variables given to me, my answer comes up wrong. Is there a concept I'm missing? My class never covered toroids so I'm pretty much on my own for this one. Thanks!