is drift velocity uniform velocity or not uniform?
what is drift mobility?

 

is drift velocity uniform velocity or not uniform?
what is drift mobility?

Drift velocity is the average velocity of electrons in a particular direction. That doesn't directly answer your question because, electrons do not travel in straight lines, they bump into things and will move randomly with a tendency to move under the influence of an external force. So, since you've posted this in Homework Help, I will not give you a, "The answer is _____".
http://en.wikipedia.org/wiki/Drift_velocity

Drift mobility is how quickly a particle can move through a material, don't know how else to phrase that one....
http://en.wikipedia.org/wiki/Electron_mobility