asked 13.4k views
3 votes
A solid uniformly charged insulating sphere has uniform volume charge density p and radius R. Apply Gauss's law to determine an expression for the magnitude of the electric field at an arbitrary distance r from the center of the sphere, such that r < R, in terms of rho and r

asked
User Cea
by
8.0k points

1 Answer

4 votes

Final answer:

To determine the magnitude of the electric field at an arbitrary distance r from the center of a uniformly charged insulating sphere, we can apply Gauss's law. The magnitude of the electric field is given by E = (4/3) * p * r / ε₀, where p is the uniform volume charge density, r is the distance from the center of the sphere, and ε₀ is the permittivity of free space. This expression holds true as long as r is less than the radius of the sphere.

Step-by-step explanation:

To determine the magnitude of the electric field at an arbitrary distance r from the center of a uniformly charged insulating sphere, we can apply Gauss's law. Gauss's law states that the total electric flux through a closed surface is proportional to the total charge enclosed by that surface. By applying Gauss's law to a spherical surface of radius r and finding the charge enclosed by that surface, we can determine the electric field. In this case, since we are considering a solid uniformly charged insulating sphere, the charge enclosed by the spherical surface will be the total charge of the sphere.

Since the sphere has a uniform volume charge density p, we can calculate the charge Q enclosed by a spherical surface of radius r by multiplying the volume of the sphere enclosed by the surface by the volume charge density:

Q = (4/3)πr³p

By applying Gauss's law to the spherical surface, the electric flux through the surface is given by Φ = E * A, where E is the magnitude of the electric field and A is the surface area of the spherical surface:

Φ = E * (4πr²)

Since the sphere has a uniform charge distribution, the electric field will also have a spherically symmetric distribution. Therefore, the electric field will only have a radial component (along the line connecting the center of the sphere and the point where the electric field is being observed):

E = E(r)*âr

Using Gauss's law, we can equate the electric flux through the spherical surface with the charge enclosed:

Φ = Q / ε₀

Substituting the expressions for Φ, Q, and A:

E * (4πr²) = (4/3)πr³p / ε₀

Simplifying the equation:

E = (4/3) * p * r / ε₀

Therefore, the magnitude of the electric field at an arbitrary distance r from the center of the uniformly charged insulating sphere, such that r < R, is given by E = (4/3) * p * r / ε₀.

answered
User Antonio Vida
by
7.8k points