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: Calculate the energy stored in Capacitor and Inductor

  1. May 13, 2012 #1
    1. The problem statement, all variables and given/known data
    A circuit consists of an 800mH inductor, a 20mF capacitor, and a switch, all in series.The capacitor is charged with an initial charge charge of Q = 400mC, and the switch is closed at t= 0.
    Calculate the energy stored in the Inductor and Capacitor at t = 100ms.

    2. Relevant equations
    U= 1/2LI^2 + 1/2Q^2/c

    3. The attempt at a solution
    I= 3.16A
    U=7.94J, there is no anwser key, it is a past exam that i do not have a key for. I feel i may have done this incorrectly since its asking for at t = 100ms, and U as a function of time is a sin/cos graph....
    Last edited: May 13, 2012
  2. jcsd
  3. May 13, 2012 #2


    User Avatar

    Staff: Mentor

    You haven't supplied a complete problem statement; there's no circuit or component values.
    Your Relevant Equation isn't an equation.
    Your Attempt at a Solution isn't an attempt at a solution; if you provide a complete problem statement and your attempt, then we will know how to help.
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook