- #1
arierreF
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Homework Statement
A conducting bar of length is placed on a frictionless inclined plane which is tilted at
an angle [itex]θ[/itex] from the horizontal, as shown in annexed figure.
A uniform magnetic field is applied in the vertical direction. To prevent the bar from
sliding down, a voltage source is connected to the ends of the bar with current flowing
through. Determine the magnitude and the direction of the current such that the bar will
remain stationary.
Homework Equations
[itex]\vec{F_{B}} = q\ \vec{v}\times \vec{B}[/itex]
[itex]\vec{F_{B}} = i\ \vec{l}\times \vec{B}[/itex]
The Attempt at a Solution
The magnitude i think it is obvious.The gravitational force action on particle is:
[itex]F = mg sin\theta [/itex]
So in order to cancel this force, the magnitude of magnetic force is:
[itex]|F_{B}| = mg sin\theta [/itex]The magnitude of the current is:
[itex]|i| = \frac{mg sin\theta }{l B sin 90 -\theta } [/itex]My problem is too find the direction of the current mathematically. I can easily know it by applying the right hand rule.
Any tip for getting the current direction?