A planar insulating sheet with an infinitesimal thickness has charge per unit area σ and is parallel to the x−z plane, as shown. (The arrows indicate that the object extends for a long distance in the horizontal plane.) By the symmetry of the problem, the electric field may be expressed as E⃗ =Ej^. This problem relates the change in the electric field from the lower side to the upper side of the insulating sheet to the surface charge density.

a) Enter a vector expression, in Cartesian unit-vector notation, for the electric field at points just above the planar insulating sheet.
b)Enter a vector expression, in Cartesian unit-vector notation, for the electric field at points just below the planar insulating sheet.

Respuesta :

a. The electric field above the planar insulating sheet is Ej = (σ/ε₀)j

b. The electric field below the planar insulating sheet is -Ej = -(σ/ε₀)j

a. Electric field above planar insulating sheet

The electric field above the planar insulating sheet is Ej = (σ/ε₀)j

Gauss's law

Using Gauss' law ε₀∫E.dA = q where

  • ε₀ = permittivity of free space,
  • E = electric field vector normal to the surface above the planar insulating sheet = Ej,
  • dA = normal vector to surface above the planar insulating sheet = dAj,
  • q = charge enclosed by Gaussian surface on planar insulating sheet = σA where
  • σ = surface charge density and
  • A = area of surface

Now, ε₀∫E.dA = q

ε₀∫Ej.dAj = σA

ε₀∫EdA = σA

ε₀E∫dA = σA

ε₀EA = σA

ε₀E = σ

E = σ/ε₀

So, the electric field above the planar insulating sheet is Ej = (σ/ε₀)j

b. Electric field above below insulating sheet

The electric field below the planar insulating sheet is -Ej = -(σ/ε₀)j

Gauss's law

Using Gauss' law ε₀∫E.dA = q where

  • ε₀ = permittivity of free space,
  • E = electric field vector normal to the surface below the planar insulating sheet = -Ej,
  • dA = normal vector to surface below the planar insulating sheet = -dAj,
  • q = charge enclosed by Gaussian surface on planar insulating sheet = σA where
  • σ = surface charge density and
  • A = area of surface

Now, ε₀∫E.dA = q

ε₀∫-Ej.-dAj = σA

ε₀∫EdA = σA

ε₀E∫dA = σA

ε₀EA = σA

ε₀E = σ

E = σ/ε₀

So, the electric field below the planar insulating sheet is -Ej = -(σ/ε₀)j

Learn moe about electric field of planar insulating sheet here:

https://brainly.com/question/13563493