Question

In many situations, to find the electric field using the gauss law, we can use the simplified equation $\left|\overset{ \rightarrow }{E}\right|=\frac{q_{enclosed}}{\epsilon _{0} \left|\overset{ \rightarrow }{A}\right|}$ , where $\epsilon _{0}$ is the permittivity of free space, $A$ is the area of Gaussian surface and $q_{enclosed}$ is the net charge enclosed by the Gaussian surface. Among the following situations, this equation can be used

• A. only when the Gaussian surface is an equipotential surface
• B. only when $\left|\overset{ \rightarrow }{E}\right|$ is constant on the surface
• C. only when the Gaussian surface is an equipotential surface and $\left|\overset{ \rightarrow }{E}\right|$ is constant of the surface
• D. for any choice of Gaussian surface

Answer 1

Answer: (C)

Magnitude of electric field is constant $\&$ the surface is equipotential