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cseil
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Homework Statement
There's a straight wire through which passes a current of 48.8A.
There's an electron moving with velocity 1.08x10^7 m/s at distance 5.20cm from the wire.
I have to calculate the magnetic force on the electron when:
a) the velocity is directed perpendicularly to the wire
b) the velocity is directed parallel to the wire
c) the velocity is perpendicular to the other two directions (a,b)
Homework Equations
Biot-Savart's law
[itex]B = \frac{μ_0i}{2πr} [/itex]
[itex]F = q\vec{v}× \vec{B}[/itex]
The Attempt at a Solution
B generated by the wire is 1.88x10^-4 T
The direction of B is perpendicular to i and the vector [itex]\vec{d}[/itex] (the distance between the wire and the electron). I considered the i going from left to right, so the vector B points inside the plane.
(a) Considering that, the force should be perpendicular to [itex]\vec{v}[/itex] and [itex]\vec{B}[/itex] so, with v directed to the wire, parallel to the wire but directed opposide to the current. The value is ok, I can calculate it, but I don't know if verse is right. My book says that the force is parallel and has the same verse of the current. I don't know why.
(b) If B points inside the plane, v is parallel to the wire, F points to the wire. It has the same value of (a).
(c) F is 0 because v is parallel to B.