試題詳解

44. According to the Drude model, the speed of charge carriers driven in conducting media can be described by the concept of drift velocity under a bias voltage. Also, charge carriers (say, electrons) are used to be treated as free particles like ideal gas molecules that are thermally agitated into random motion with an average velocity . In common situations, what the estimated ratio (in the order of magnitude) of would be?
(A) or even more
(B) around 10⁵
(C) about 1
(D) around  
(E) or even less