ABSTRACT
We already know that the magnetic field does no work on charges on its own. This is connected with the fact that the Lorentz force is always perpendicular to the velocity of the particle it is acting on. We may see that magnetic forces acting on electric currents https://www.w3.org/1998/Math/MathML"> j → https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429086748/b73d63a9-8262-4950-bec8-f781f20f85f6/content/eq3444.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/> do not perform any work directly on the charges. The elementary work of the magnetic force may be written as follows: () https://www.w3.org/1998/Math/MathML"> ∂ W = j → ⋅ F → L dV https://s3-euw1-ap-pe-df-pch-content-public-p.s3.eu-west-1.amazonaws.com/9780429086748/b73d63a9-8262-4950-bec8-f781f20f85f6/content/eq3445.tif" xmlns:xlink="https://www.w3.org/1999/xlink"/>
