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!

Homework Help: Compare charge and current

  1. Aug 21, 2015 #1
    1. The problem statement, all variables and given/known data

    We have seen that a coulomb is an enormous amount of
    charge; it is virtually impossible to place a charge of 1 C on an
    object. Yet, a current of 10 A, is quite reasonable. Explain
    this apparent discrepancy.

    2. Relevant equations
    I = nqvA

    3. The attempt at a solution
    i think it is because current is the amount of charge flow per second, and the amount of charge depends on the volume of the wire, hence current can be larger than the placed charges if volume of the wire is pretty big. is this a good answer? is there anything to add? thx
  2. jcsd
  3. Aug 22, 2015 #2
    I agree with: As you've already said, current is defined as the amount of charge flow per second, there could be many charges little charges but summing them up will result in 1 C, bigger volume mean less resistance so more current flow this can be explained (the bad way) because charges have more space to avoid hitting static atoms in the wire (also the reason you've mentionned) and I should mention all the charges flow on the surface,any way if we get into the math, ## I = \frac{\delta Q}{\delta t} ##, if we take for example ##\delta t = 0.01 s## mesure that ##\delta Q = 0.1C## passed, then we conclude that I = 10A, Cheers :D
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted