Let us consider a fixed Carthesian reference frame (x y z) with a charged (+) particle locate in its origin. Moreover, let us consider two parallel conductors of infinite lenght, carrying the same current I (in the same direction y). The two conductors move at constant velocity from the origin, starting from time t=0 (the two conductors then occupy the loci x=Vt and x = -Vt, for all t>0) . My question is: what is the correct behavior among the two listed below? 1) Being the induction B field constantly B = 0 incorrespondence of the charge, then no Force is exerted on the particle. 2) The effect of the two moving conductors sum at Electric field level, such as the charge in the origin is subjected to the force F = 2 q cross(-V,B(t)), being B(t) the field due to a single conductor at time t and -V the velocity of the particle relative to the induction field.