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: Three Kind of electrostatics problem(quite )

  1. Mar 18, 2008 #1
    Three Kind of electrostatics problem(quite urgent)

    1. The problem statement, all variables and given/known data
    The first kind of prbolem is about the dielectric coefficient

    I know the equations below
    but I don't know how to relate the E-field into eqn1
    The main reason is that I don't know is the D related in this kind of problem?

    2. Relevant equations
    [tex]\frac{tan\alpha1}{tan\alpha2}[/tex] = [tex]\frac{K1}{K2}[/tex]
    where alpha1 is incidence angle
    K is dielectric coefficient

    where D is electric displacement
    E is E-field


    where [tex]\epsilon[/tex]o is the permittivity of dielectric
    [tex]\epsilon[/tex] is the permittivity of vaccum

    1. The problem statement, all variables and given/known data
    The second type of problem is about the simplest electrostatic problem!!!!!!!
    I don't really understand the meaning of "potential" is zero.
    Doesn't the potential is set by us?
    I know that when the net force is zero, then the PE should be minimum.
    But these problems make me very confusing.

    1. The problem statement, all variables and given/known data
    The last kind of question is about the leakage and capacitance.

    The equation related:
    where [tex]\sigma[/tex] is lossy dielectric of conductivity

    I cannot really remember the previous concept of capacitance very well
    but I know that the time constant(decay to half ) is RC

    this problem are something new for me
    and I wanna know how to use the idea of lossy dielectric of conductivity
  2. jcsd
Share this great discussion with others via Reddit, Google+, Twitter, or Facebook

Can you offer guidance or do you also need help?
Draft saved Draft deleted