# Problem: Suppose a straight 1.40 mm -diameter copper wire could just "float" horizontally in air because of the force due to the Earth's magnetic field B⃗ , which is horizontal, perpendicular to the wire, and of magnitude 4.0×10−5 T. What current would the wire carry? Does the answer seem feasible

###### FREE Expert Solution

Magnetic force:

$\overline{){\mathbf{F}}{\mathbf{=}}{\mathbf{i}}{\mathbf{L}}{\mathbf{B}}}$

Density:

$\overline{){\mathbf{\rho }}{\mathbf{=}}\frac{\mathbf{m}}{\mathbf{V}}}$

Where m is the mass and V is the volume.

ρcopper = 8.96 × 103 kg/m3

The weight of the wire acts downward. Thus, the magnetic force should act upward.

###### Problem Details

Suppose a straight 1.40 mm -diameter copper wire could just "float" horizontally in air because of the force due to the Earth's magnetic field B , which is horizontal, perpendicular to the wire, and of magnitude 4.0×10−5 T. What current would the wire carry? Does the answer seem feasible

What scientific concept do you need to know in order to solve this problem?

Our tutors have indicated that to solve this problem you will need to apply the Magnetic Force on Current-Carrying Wire concept. You can view video lessons to learn Magnetic Force on Current-Carrying Wire. Or if you need more Magnetic Force on Current-Carrying Wire practice, you can also practice Magnetic Force on Current-Carrying Wire practice problems.