Question

are the path of electrons straight line between successive collision with positive ions of the metal in the absence of electric field presence of electric field​

Answer 1

in the absence of electric field it should be straight line

in presence of electric field it slightly drifted in a direction opposite to the electric field

Answer 2

In the absence of E. field the paths are not straight lines as the electrons can deviate anywhere inside the metal sheet ... But in the presence of E. field the electrons after colliding with the +ve ions deviate in such a way that it goes again in the direction of electric field that means you can imagine water flowing over a small stone but the bottom line is the path of the electron..