Two anti-parallel currents have a common diameter D = .0033m, spacing between th
ID: 2121600 • Letter: T
Question
Two anti-parallel currents have a common diameter D = .0033m, spacing between them d = .001m, a common interacting length L = .25m, and each carrying the same current I = 8A. The lower current is into the paper. What is the direction and magnetic field due to this current at the position of the upper current? What is the direction of the force on the top current-carrying rod? Calculate the magnitude of the force on the upper current carrying rod. Determine in mass whose weight on the top conductor would just equal the force calculated in the question above. Please show work for first, best, and only rated answer.
Explanation / Answer
B = mue*i/(2*pi*r) = 1.6*10^-3 T
direction of B is towards +x axis
force on upper wire F = B*i*L = 1.6*10^-3*8*0.25 = 3.2*10^-3 N
direction upward (+y axis)
F = m*g
m = F/g = 3.2*10^-3/9.8 = 0.32*10^-3 kg = 0.33 gram