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Homework Help: Maximum charge

  1. Jun 25, 2005 #1
    Me again.

    Is there a formula for the maximum amount of charge may be stored on a body (assume spherical) of radius r? I assume radius is the only factor, though mass is known also. I just don't remember seeing anything for this and can't find it in all my books for the life of me.

  2. jcsd
  3. Jun 26, 2005 #2
    Lets try ::
    Capacitance:: C=[tex]4 \pi \epsilon r[/tex]
    [tex]Q=4 \pi \epsilon r V[/tex]
    Now V should be less than E0 Breakdown Voltage
    so max can be
    [tex]Q_{max} = 4 \pi \epsilon r E_0 [/tex]
    Well I am not too sure abt above but its a try , if u can provide some other logic it will be welcomed
  4. Jun 26, 2005 #3
    Dammit, sorry I was being dumb. I didn't notice we were given the electrical breakdown of air in the problem, so I know the maxmum electric field, I know the radius, and from this I can easily get the charge:

    Q = [tex]4 \pi \epsilon r^2[/tex]E(r)

    Apologies for wasting thine time, and thanks for posting back. I was pretty tired. :zzz: Take care.
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