Electric field inside charged conducting sphere?

[mohamed el teir]

i know it s zero because of the electrostatic equilibrium, but in terms of point charges : from the charge distribution on the sphere surface if we consider 2 point charges opposite to each other in direction : it s logical that at the point in the mid distance between them the electric field will be zero : (kq1/r1^2)=(kq2/r2^2) where q1=q2 and r1=r2, but if we consider a point closer to a point charge than the other charge : q1=q2 also but r1 not equal r2, therefore it s logical that there will be net field at this point, but there is no field at any point inside the sphere, so what is the solution of this contradictory ?

 

[robphy]

It's not just about those two point charges.
A brute-force calculation might help... after which one might have more appreciation for Gauss' Law.

 

[DaPi]

Very very crudely (I hate to do this) it's because for a point off-centre there are more point charges on the sphere further away than there are closer - the effect balances out exactly when you add them all up. Surely any E&M textbook shows how to do the integration.

 

[mohamed el teir]

Very very crudely (I hate to do this) it's because for a point off-centre there are more point charges on the sphere further away than there are closer - the effect balances out exactly when you add them all up. Surely any E&M textbook shows how to do the integration.

nailed it ! thanks man ...