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mihuhifitechno
mihuhifitechno
Student
High School - 10th Grade

Find the maxim potential a sphere can be loaded; at normal atmospheric pressure, discharge in air is produced at the electric field, E0=3.0MV/m.

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Posted by mihuhifitechno on Friday June 26, 2009 at 5:59 AM and tagged with electric, field, load, potential, science.


Answers:

  1. neela
    neela Teacher
    Graduate School

    eNotes Editor

    By Gauss' theorem, the electrical intensity, E due to a charge  q on a spherical conductor of radius d is given by :

    E ={1/(4pi*e0)}(q/d^2)

    Where e0  is a dielectrical constant for air which is  1.00054.

    The discharge intensity is given to be E0 =3.0 MV/m/

    Therfore,the maximum potential q that can be loaded on the spherical conductor is given by:

    q = 4pi*e0*d^2*E0.

    =(4pi*1.00054*d^2)*3 M.V

    =37.7195d^2 M.V.

    Therefore the maximum potential that can reside on a spherical conductor of radius d meter   is 37.7195*d^2 M*V/m

    Hope this helps.

     

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    Posted by neela on Friday June 26, 2009 at 10:24 AM

  2. giorgiana1976
    giorgiana1976 Teacher
    Doctorate

    eNotes Editor

    Best answer as selected by question asker.

    Outside of a sphere, the potential and the field are the same as the sphere's load would be centered.

    V=Q/(4*pi*epsilon*r) and E=Q/(4*pi*epsilon*r^2), r>R

    At the sphere's surface, the field is maxim, so appears the risk of abrupt discharge:

    Emax=Q/(4*pi*epsilon*R^2)=Eo, Q=4*pi*epsilon*R^2*Eo

    Vmax=Q/(4*pi*epsilon*R)=R*Eo

    If R=0.10m, R*Eo=300KV

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    Posted by giorgiana1976 on Saturday June 27, 2009 at 6:46 AM