1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Drift velocity in a resistor?

  1. Jan 29, 2012 #1

    An Si resistor is at 300Kelvin, and is 100μm long, 1μm thick, 5μm wide. The conductivity is 7.128 Ωcm. The resistance is 28058Ω. A voltage of 5v is applied. What is the drift velocity of the electrons, given that n = 1.01x103?
    Other constants:
    μn = 1350 cm2/Vsec
    μp = 450 cm2/Vsec
    My work:
    So basically,
    I have the formula Jn,drift = qn(μnE).
    The question asks for drift velocity, does that mean I'm trying to find Jn,drift or just the mobility factor μnE? What exactly is Jn,drift? In either scenario, how do I find E field if I'm only given a voltage? It's not like I can integrate b/c Voltage is constant through the resistor.
    I was also considering using I = nqvdA. But I was getting some outrageous velocity with this.
    Thank you.
  2. jcsd
  3. Jan 29, 2012 #2
    Jn,drift is probably the drift current of negative carriers (electrons). In a semiconductor you may have also drift current of holes as well as diffusion currents of both types of carriers.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook