Question

Which of the following charge distributions can be accurately replaced by a single charge of magnitude Q at the origin (x=0,y=0,z=0) for the purposes of calculating the electric field at the location (x=0m , y = 0m, z = 2m).

a) a small solid sphere of radius r=0.5m and with a uniformly distributed charge of Q

b) a large solid sphere of radius r=4m and with a uniformly distributed charge of Q

c) a small spherical shell of inner radius r 1 =0.3m, outer radius r 2 =0.5m, and a uniformly distributed charge of Q

d) a medium-sized spherical shell of inner radius r 1 =1.5m , outer radius r 2 =2.5m, and a uniformly distributed charge of QQ

e) a large spherical shell of radius r 1 = 3.0m, the outer radius r 2 =5.0m, and a uniformly distributed charge of Q

f) two thin spherical shells; the first shell having a radius of r_1 = 0.7mr 1 =0.7m and a uniformly distributed charge of Q 1 ; the second shell having a radius of r2 =1.3m and a uniformly distributed charge of Q 2 , where Q = Q 1 +Q 2

g) 8 equal positive charges, each of magnitude Q/8 arranged in a cube centered on the origin.

Answer 1