In a solid metallic conductor with no external electric field applied, the average velocity of the free electrons is

1. With no field, electrons move only due to random thermal motion. 2. After each collision the direction of velocity is completely random. 3. The number moving in any direction equals the number in the opposite direction, so the vector average is zero. 4. Hence there is no net current; the answer is D. _Source: syllabus Physics Ch 3 "Current Electricity", p.2_