Guys, I'm having trouble with some concepts on the Biot-Savart Law. Lots of texts compare this law with Coulomb Law, but doesn't affirm that B-S is only applicable on a static case (constant current). What are the real physical conditions in which Biot-Savart Law can be directly applied? Does it covers the instant eletromagnetic effects with the distance (as the Coulomb Law doesn't)? Also, to surpass the instant effects over distance, could I aplly the Ampere-Maxwell law? Thanks!