Magnetic Force on Current-Carrying Wire Video Lessons

Concept

# 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.

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###### 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