A wire carries a current of 11.1 A in a direction that makes an angle of 29.2° with the direction of a magnetic field of 0.239 T. Calculate the magnetic force on a 3.96 m length of the wire.

Question

festinger · Answer

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The full description requires vector products but I'll skip that here to keep it simple.

The force on the wire proportional to the length of the wire that is perpendicular to the magnetic field. This gives us

$$L'=Lsin\theta$$

Magnitude of Magnetic force on a current carrying conductor is
$$F=IL'B$$
Where I is current, L' is the length of the wire that is perpendicular to the magnetic field and B is the magnetic field. Putting it all together yields

$$F=BILsin\theta$$

Substituting the magnetic field should yield you the answer.
$$F\approx 5.13N$$