Figure P21.81 shows the electric potential on a grid whose squares are \(5.0 \mathrm{~cm}\) on a side.

a. Reproduce this figure on your paper, then draw the \(50 \mathrm{~V}, 75 \mathrm{~V}\), and \(100 \mathrm{~V}\) equipotential surfaces.

b. Estimate the electric field (strength and direction) at points \(\mathrm{A}, \mathrm{B}, \mathrm{C}\), and \(\mathrm{D}\).

c. Draw the electric field vectors at points A, B, C, and D Potential in \(\mathrm{V}\) on your diagram.

0 25 50 50 50 25 50 75 100 50 C A B 50 75 100 100 50 D 25 50 75 100 50 0 25 50 50 50 Potential in V FIGURE P21.81