This force names the dual Yang–Mills theory with strong coupling in Montonen-Olive duality. A gravitational analog (15[1])of this force is often used to explain the frame-dragging caused by rotating objects. The components (15[1])of this force are the spacelike components of the Faraday tensor. (15[2])What appears to be this force in the observer frame can be derived (-5[1])as a consequence (-5[2])of length contraction of a (15[1]-5[1])(*) charge (-5[1])density (10[2]-5[1])in a moving particle's rest frame, which is why this force is unified with a counterpart in special relativity. (10[1]-5[1])This force can do (-5[1])no work, (10[2]-5[1])since the (10[1])direction (10[2]-5[1])of this force (10[3])on a particle (10[2])is always perpendicular (10[1])to its motion (10[1]-5[2])and equals (10[1]-5[2])“q v cross (10[1])B.” (-5[1])For 10 points, moving charges give rise to what force that is (10[1])combined (10[1])with electricity (10[2])in Maxwell’s (10[1])equations? (10[1])■END■ (10[13]0[3])