Plates and Voltage - Capacitors & Stored Charge Step by Step

Ideal parallel plates make a clean field case where voltage divided by distance gives the central field. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

Place two ideal plates

Two ideal plates separated by 3 metres have a central region where the field is uniform.

d = 3\ \text{m}

Apply a voltage

A voltage of 12 volts across the gap sets the field strength.

V = 12\ \text{V}

More voltage makes a stronger field

Hold the plate gap at 3 metres. The ideal central field grows in direct proportion to the applied voltage. The diagram shows the middle row.

\begin{array}{c|c|c}V&d&E\\6\ \text{V}&3\ \text{m}&2\ \text{N/C}\\12\ \text{V}&3\ \text{m}&4\ \text{N/C}\\18\ \text{V}&3\ \text{m}&6\ \text{N/C}\\\end{array}