Question

A segment of wire carries a current of 46 A along the x axis from x = −6 m to x = 0 and then along the z axis from z = 0 to z = 6.9 m. In this region of space, the magnetic field is equal to 120 mT in the positive z direction. What is the magnitude of the force on this segment of wire? Answer in units of N.

Answer 1

The Lorentz force: F = I L x B,

The force is zero on the segment of wire along the z axis.

since it's vector cross-product with B is zero.

The force is nonzero on the segment of wire along the x- axis, and since this segment is exactly normal to B;

L x B = LBsin90 = LB,

therefore,

F = BLI = (120 x 10^-3)(6)(46)

F = 33.12 N