1. Not finding help here? Sign up for a free 30min 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!

Voltage across capacitor

  1. Jun 3, 2008 #1
    1. The problem statement, all variables and given/known data
    Voltage across 0.2-F cap is given by

    v(t)=4(1-Є^(-10t)) for t>0


    determine expression for the current i(t)

    2. Relevant equations

    i(t)=c (dv(t))/dt

    3. The attempt at a solution

    I'm really not sure were to begin with this problem what is the Є symbol and how do you take the derivative of it?
     
  2. jcsd
  3. Jun 3, 2008 #2

    Mapes

    User Avatar
    Science Advisor
    Homework Helper
    Gold Member

    pmontone, you're in luck. That's not a Є symbol, but rather the constant e (= 2.718), the basis for the exponential function.
     
  4. Jun 10, 2008 #3
    First, look at your given equation v(t) and try to understand its meaning. What happens to v(t) as t increases? Is this equation representative of a "charging" or "discharging" capacitor? Now, based on this answer, how do you expect the current across the capacitor to behave over time? Use your equation and then analyze the result for physical accuracy. Remember that a fully-charged capacitor acts as an open circuit (no current).
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?



Similar Discussions: Voltage across capacitor
Loading...