Parallel Plate Capacitor

How to Use

• Area slider — change the plate area (1–100 cm²). Larger area = more capacitance.
• Sep slider — change the plate separation (1–20 mm). Closer plates = more capacitance.
• Voltage slider — set the applied voltage (1–100 V) to see stored energy and charge change.
• Dielectric buttons — select the insulating material between the plates. Higher εᵣ = more capacitance.

What to Observe

• Capacitance \(C = \varepsilon_0 \varepsilon_r \frac{A}{d}\) updates in real time.
• The electric field arrows between the plates grow denser as field strength increases.
• Stored energy \(E = \frac{1}{2}CV^2\) grows with the square of voltage — doubling voltage quadruples energy.
• Different dielectric materials produce dramatically different capacitance values at the same geometry.

Key Equations

\[C = \varepsilon_0 \varepsilon_r \frac{A}{d}\]

\[E_{stored} = \frac{1}{2}CV^2\]

\[\mathcal{E} = \frac{V}{d} \quad \text{(electric field between plates)}\]