A positive charge +q is placed at the centre of a hollow metallic sphere of inner radius a and outer radius b. the electric field at a distance r from the centre is denoted by E. In this regards, which one of the following statement is correct?

Option 1 : E = 0 for a < r < b

Concept:

• According to gauss law,
• "The total flux of electric field through any simple connected closed surface is equal to the total charge enclosed by that surface, divided by electric permittivity of material".
• It can be used to find the charge on simple surfaces which can be called Gaussian surfaces.
• The expression for the law is ϕ = q / ϵ₀ where
  • q = charge enclosed by the surface
  • ϵ₀ = electric permittivity constant

Explanation:

• We know that if a charge in closed inside a uniform surface its Electric field inside a surface is zero
• So in this case charge is kept at the center of concentric spherical shell hence charge will be induced on each of the surfaces because of flux passing through them
• But there will be a point between two spherical surfaces where the net Electric field is zero.
• Hence at any point between a and b, the net Electric field will be zero