posted by blasting(right hand rule) .
How do i figure out the direction for this problem: A wire having a mass per unit length of 0.500 g/cm carries a 2.00 A current horizontally to the south. What is the direction of the minimum magnetic field needed to lift this wire vertically upward?
The minimum magnetic field would be oriented perpendicular to the wire.
If current I is to the south, the force on the wire will be up if B is pointing east.
(right hand rule, I x B)