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How do i find the higher electric field of these two

  • Thread starter Dell
  • Start date
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given a ball and an infinite pipe, both with the same radius and same charge density [tex]\sigma[/tex]
what is the total electric field at the meeting point of the 2 if we bring them close together so that they touch at point A?

what i did was:

the ball has spherical symetry and the pipe has cylindrical symetry, so those are the shapes i will use for my gauss law,

since RA=R

for the ball
[tex]\Phi[/tex]=EA=E(4[tex]\Pi[/tex]R2)=[tex]\sigma[/tex](4[tex]\Pi[/tex]R2)/[tex]\epsilon[/tex]0

E=[tex]\sigma[/tex]/[tex]\epsilon[/tex]0

for the pipe
[tex]\Phi[/tex]=EA=E(2[tex]\Pi[/tex]R*L)=[tex]\sigma[/tex]2[tex]\Pi[/tex]R*L)/[tex]\epsilon[/tex]0

E=[tex]\sigma[/tex]/[tex]\epsilon[/tex]0

does this mean that the total field at point A will be 0 since they have the same field in opposite directions?
does that make sense?
 

Redbelly98

Staff Emeritus
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Looks right to me.
 

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