In a region of constant potential

Options

A. the electric field si uniform
B. the electric field is zero
C. there can be no charge inside the region
D. the electric field shall necessarilly change if a charge is placed outside the region

Answer

B, C

Explanation

In a region of constant potential (V = constant) , `E = - (dV)/(dr) = 0`, i.e., electric field is zero.
As `E = 0`, there can be no charge inside the region.
Choices (b) and (c ) are correct.