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!

True of False

  1. Feb 16, 2009 #1
    1. The problem statement, all variables and given/known data
    A parallel plate capacitor with plate separation d is connected to a battery. The capacitor is fully charged to Q Coulombs and a voltage of V Volts. (C is the capacitance and U is the stored energy.) Give all correct answers concerning a parallel-plate capacitor charged by a battery (e.g. B, AC, CDF). If none of the statements is correct, enter the word none.

    A) After being disconnected from the battery, inserting a dielectric with kappa > 1 will decrease V.
    B) After being disconnected from the battery, increasing d increases U.
    C) After being disconnected from the battery, increasing d decreases V.
    D) With the capacitor connected to the battery, inserting a dielectric with kappa > 1 will increase U.
    E) After being disconnected from the battery, inserting a dielectric with kappa > 1 will increase C.
    F) After being disconnected from the battery, decreasing d decreases C.


    3. The attempt at a solution
    ok so i had thought it was ACD but that was said to be wrong. dont know where i am going wrong
     
  2. jcsd
  3. Feb 16, 2009 #2

    Delphi51

    User Avatar
    Homework Helper

    I think C is false. Increasing d will decrease C, so V = Q/C will increase.
    I would say D is false, too. Using V = Q/C in U=.5CV^2 = .5Q^2/C means that when C increases, U decreases.
    E is true - the dielectric makes it a better capacitor with greater C
    F is true - greater capacitance with reduced D.
     
  4. Feb 16, 2009 #3

    LowlyPion

    User Avatar
    Homework Helper

    This should answer all your questions.
    A good presentation of the material.

    https://www.youtube.com/watch?v=E185G_JBd7U
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: True of False
  1. True or False (Replies: 5)

  2. True or False (Replies: 25)

Loading...