You are going to wrap a toroid with 273 m of copper wire that can carry a current of I = 1.7 A. The toroid has radius R = 16 cm and cross sectional diameter D = 1.2 cm. How large a magnetic field (T) can you make at the average toroidal radius? I have been using the formula B = ([tex]\mu[/tex]*N*I)/2*[tex]\pi[/tex]*R where [tex]\mu[/tex] = 4[tex]\pi[/tex]*10^-7, N = number of windings of the coil, and I is the current...I have no idea how to figure out N though. Any help would be greatly appreciated.