Drift velocity is the average velocity of charge carriers in a conductor. It is much smaller than the actual speed of individual electrons since they move randomly through a material. Drift velocity depends on factors like the material, temperature, and strength of the electric field applied. It can be calculated using the formula vd=μE, where vd is drift velocity, μ is mobility, and E is the electric field strength.

1. http://electrical-engineering-portal.com/
http://www.electrical4u.com/basic-electrical/drift-velocity.php