Final answer:
Equipotential lines get further apart due to the increased potential difference between the plates.
Step-by-step explanation:
Equipotential lines are lines that connect points in a field where the electric potential is the same. In the case of parallel conducting plates, the equipotential lines are evenly spaced and parallel. As the potential difference between the plates increases, the equipotential lines get further apart. This is because the electric field between the plates is stronger, causing a greater change in electric potential per unit distance and resulting in wider spacing between the equipotential lines.When analyzing a familiar case like the one between parallel conducting plates shown in Figure 19.16, the equipotential lines are parallel and evenly spaced, reflecting a uniform electric field. This spacing changes with the strength of the electric field; closer spacing indicates a stronger field, and lines that are further apart indicate a weaker field. Similarly, we can draw equipotential lines for gravitational fields, like on a hill where the lines would be evenly spaced on areas of constant slope, and the same principles apply.