# why boundary condition in steady electric current?

when we electric field between two conductors in certain direction the current density should pass in its direction why current density direction change at boundary although the direction of electric field is the same for both conductors

• Which picture are you taking about? is it the background one or the one you drew above it? Your question is not clear Oct 12 '13 at 17:31
• no the one i drew above i want this case specifically Oct 12 '13 at 18:02
• i mean according to new picture why current density J change direction at boundary according to boundary conditions jn1=jn2 and Et1=Et2 although the electric field direction due to potential should keep the same Oct 12 '13 at 18:10
• Just to ensure I understand your question correctly, you are asking why would the current density be different when there is a tilted interface between two materials having different conductivities while the electric field across that interface is constant, is that correct?? Oct 12 '13 at 21:34
• no also why electric field change its direction between boundary although the source is fixed so that the direction of electric field should be fixed Oct 13 '13 at 7:23