In finding the electric field using Gauss law the formula E→=qenc∈0A→  is applicable. In the formula ∈0  is permittivity of free space, A is the area of Gaussian surface and qenc  is charge enclosed by the Gaussian surface. This equation can be used in which of the following situation?

Gauss Law, ∮E→.dA→=qenc∈0​⇒∮E→ dA→ cosθ = qenc∈0If E→ is perpendicular to surface at all points , then angle between​electric field and area vector is 0o.  It means surface is equipotential⇒∮E→ dA→ = qenc∈0​If E→ is constant, it can be taken out of integration sign, ⇒E→ ∮dA→ = qenc∈0​⇒E→ A→ = qenc∈0⇒E→ =qenc∈0A→