00:01
Hi there, so for this problem, we are told that you need to use the result in problem 2 .7 to find the field inside and upside a sphere of radius capital art, which carries an uniform volume charge density row, and we need to express your answer in terms of the total charge of this sphere.
00:25
And also we need to draw a graph of the electric field as a function of the distance from the center.
00:34
So we know that according to problem 2 .7, sorry, all shells interior to the point at a small radius are, contribute as though their charge were concentrated at the center, while all exterior shells contribute nothing.
00:59
So therefore, we are going to have that, the electric field for art, for a smaller, add smaller art, is going to be four times pi times, xelm sub 0 times the interior charge divided by the distance r square in a radial direction of course.
01:31
Now where the interior queue is the total charge interior to the point.
01:38
Now upside the sphere all the charge is interior.
01:44
So for the upside, upside, we're going to have that.
01:53
Field is just simply 1 over 4 times 5 and epsilon sub 0 times the total charge q divided by the separation distance r to the square in the radial direction.
02:11
Now with that we can conclude that inside the sphere only that fraction of the total which is interior to the pound counts.
02:24
So the interior charge is equal to 4 over 3 times pi times the radius to the 3 where this radius is less than the radius of the sphere divided by 4 times 3 times 3 times the total radius of the sphere to this to the 3 and this times the total charge q so we can cancel some terms in here and then the interior charge is 3, r to the 3 divided by the radius of the sphere to the 3 times the charge q.
03:09
So with this, we can use this equation right here and obtain that for inside the sphere, the electric field is equal to 1 over 4 times pi times epsilon sub 0 times the charge q divide by the charge of the, well, in here, this is for inside...