Answer to Question #205956 in Field Theory for khashayar lashgari

Question

2. A Positive electric charge Q is distributed uniformly throughout the volume of an insulating solid sphere with radius a (Figure 2). By using Gauss Law, find the magnitude of the electric field at a point P, a distance r from the center of the sphere where:

a) r𝑟 <a 𝑎 (10 points) 

b)r>a

Answer 1

a)

$$E=k\frac{qr}{a^3}$$

b)

$$E=k\frac{q}{r^2}$$