Consider a straight piece of copper wire of length 2 m and diameter 1 mm that carries cu...

Consider a straight piece of copper wire of length 2 m and diameter 1 mm that carries current I = 3.5 A. A magnetic field of magnitude B is directed perpendicular to the wire, and the magnetic force on the wire is just strong enough to “levitate” the wire (i.e., the magnetic force on the wire is equal to its weight). Find B. Hint: The density of copper is