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The original web
http://farside.ph.utexas.edu/teaching/em/lectures/node56.html
Reading the web which is posted above
I got a question ...
I need some masters to help me!
My question :
why not to remain the left term of eq539 instead of eliminating it by
"Let us assume that is a sphere, centred on the origin, and let us take the limit in which the radius of this sphere goes to infinity. We know that, in general, the electric field at large distances from a bounded charge distribution looks like the field of a point charge, and, therefore, falls off like . Likewise, the potential falls off like . However, the surface area of the sphere increases like . Hence, it is clear that, in the limit as , the surface integral in Eq. (593) falls off like , and is consequently zero." (the photograph can be seen in that web )
http://farside.ph.utexas.edu/teaching/em/lectures/node56.html
Reading the web which is posted above
I got a question ...
I need some masters to help me!
My question :
why not to remain the left term of eq539 instead of eliminating it by
"Let us assume that is a sphere, centred on the origin, and let us take the limit in which the radius of this sphere goes to infinity. We know that, in general, the electric field at large distances from a bounded charge distribution looks like the field of a point charge, and, therefore, falls off like . Likewise, the potential falls off like . However, the surface area of the sphere increases like . Hence, it is clear that, in the limit as , the surface integral in Eq. (593) falls off like , and is consequently zero." (the photograph can be seen in that web )
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