Bigger plates and a narrower gap store more charge at the same voltage. Change the geometry, slide in a dielectric, and watch C, Q and U move — while the field E = V / d stays exactly where the voltage and gap put it.
Capacitance C = ε0εrA / d
1.7708 nF
1.7708e-9 F
capacitance × 1.00 compared with a vacuum gap
Stored charge Q = C·V
21.250 nC
2.1250e-8 C
Stored energy U = ½CV²
127.50 nJ
1.2750e-7 J
Field strength E = V / d
120.00 kV/m
Set by the voltage and the gap alone — adding a dielectric does not move it.
Plate area A0.020 m²
Plate gap d0.10 mm
Dielectric εr1.0
Supply voltage V12.0 V
Vacuum permittivity ε0 = 8.8541878188e-12 F/m (CODATA 2022). Plates in vacuum or air have εr = 1.
Tip: raise the dielectric slider and watch C, Q and U all climb while the field readout refuses to budge. Halving the gap doubles the capacitance and doubles the field.