Uniform Field Samples - Electric Fields, Electrostatics & Capacitors Step by Step

This uniform-field-samples lesson checks that three central sample points share the same 4 N/C vector in the ideal parallel-plate region. The equal vectors are a model claim about the central region between ideal plates, using the stated sample positions and field value. Real capacitors can depart from this through edge fringing, nonparallel plates, dielectric variation, probe placement, finite precision, and measurement uncertainty.

In the ideal central region, each checked sample vector has the same magnitude and direction. Exact arithmetic here means exact results for the stated model inputs; measured inputs still carry uncertainty and significant-figure limits.

highlighted = computed this step

Sample the central region

The diagram samples the central region at 3 points.

\text{sample count} = 3

Read the same field each time

Each sample vector reads 4 newtons per coulomb and points the same way.

E_{\text{each sample}} = 4\ \text{N/C}

Position changes, field does not

The sample points are at different positions between the plates, but the ideal central field stays the same at each checked sample.

\begin{array}{c|c}x&E\\\tfrac{3}{4}\ \text{m}&4\ \text{N/C}\\\tfrac{3}{2}\ \text{m}&4\ \text{N/C}\\\tfrac{9}{4}\ \text{m}&4\ \text{N/C}\\\end{array}