- #1

ShayanJ

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[itex]

\delta W=\vec{F}\cdot \vec{\delta r}=I (\vec{dl}\times \vec{B})\cdot \vec{\delta r}=I[ \delta x (dy B_z-dz B_y)+...]=I[(\delta x dy-\delta y dx)B_z+..]

[/itex]

To complete the proof,I should be able to set [itex] \delta A_z=\delta x dy-\delta y dx [/itex],etc.([itex]\delta A_z[/itex] being the change in area caused by [itex] B_z [/itex]).My problem is,I don't know how to justify it!

Any ideas?

Thanks