Electrostatic fields, conductors, and dielectrics

Equipment

• 3D canvas of the electrostatic field with buttons “Mô hình A”, “Mô hình B”, and “Tạm dừng”
• Sliders “Biên độ / nguồn” (amplitude/source) and “Bước sóng / tỉ lệ” (scale)
• Figure 2: polarized-dielectric field with sliders “Tần số / vận tốc” and “Góc nhìn / hệ số”
• Readout lines plus the formula note “E ~ 1/r²; E inside = 0; D = ε₀εᵣE”

Procedure

1. Inspect the electrostatic field structure

   In figure 1, compare the two setups with the buttons «Mô hình A» / «Mô hình B», drag to rotate the view, then press «Tạm dừng» to freeze the motion and inspect the field pattern. Read the line “E ~ 1/r²; vật dẫn cân bằng có E trong = 0; …” and note how the region near the source is denser than far away.

2. Vary parameters and read the scaling

   Drag «Biên độ / nguồn» and «Bước sóng / tỉ lệ», watching the readouts a and k together with the changing field. Note that the field falls off with distance consistent with $E \propto 1/r^2$, and that inside an equilibrium conductor the total field vanishes because surface charges rearrange to cancel the applied field.

3. Analyze the polarized dielectric

   In figure 2, adjust «Tần số / vận tốc» and «Góc nhìn / hệ số»; read “D = ε₀εᵣE; góc điều khiển θ = …” and compare the field pattern inside the dielectric with outside. Interpret through $D = \varepsilon_0\varepsilon_r E$: the dielectric weakens the field within it by $\varepsilon_r$, like a conductor expelling field — but only partially, since the material merely polarizes.

4. Compare both models and predict

   Toggle «Mô hình A»/«Mô hình B» in figure 1 and record differences in the field-line pattern; then press «Chạy tiếp» to resume motion. Before setting «Góc nhìn / hệ số» in figure 2 to 0° and 90°, predict how θ and the field shape will change, then verify against the readout.

Simulation

Experiment history

Related physicists

Related library topics