Capacitors Concept

Demonstrations in Capacitors

Assortment of fixed capacitors on a lavender surface: large motor-run can, oil-filled metal case, yellow 47 MFD 600V film cap, dissected rolled-foil capacitor, brown ceramic feedthrough, large black electrolytic, and several smaller axial and radial components
Safety

Fixed and Variable Capacitors

Displays a collection of commercial fixed and variable capacitors to show how geometry, dielectric material, and voltage rating affect capacitance and physical size. Students see that capacitance does not correlate …
BK Precision Model 830A autoranging capacitance meter reading 03.5 pF, connected to Pasco parallel plate capacitor with clear circular plates at wide separation on a black rail base with ruler

Vertical Capacitor Plates with Meter

Students observe real-time capacitance changes as plate separation is varied and dielectric materials are inserted, directly verifying. The demo can also be done with a projection electroscope instead of the …
Composite image: top shows dial electroscope with needle deflected, connected via red clip lead to wooden frame with tinfoil rolled on cylinder with crank handle; bottom shows same setup with tinfoil unrolled and electroscope needle showing less deflection

Tinfoil Cylinder Capacitor

Demonstrates that increasing a conductor's surface area increases its capacitance. Charge an electroscope connected to a rolled-up tinfoil sheet, then unroll the foil and observe the electroscope deflection decrease — …
BK Precision Model 830A autoranging capacitance meter reading 154.6 pF, connected via red leads to a variable air capacitor with interleaved semicircular plates fully meshed inside a clear cylindrical enclosure

Variable Capacitor

Shows that capacitance depends on conductor geometry by varying the overlap area between interleaved plates. Students observe real-time capacitance changes on a meter as the plates are rotated, reinforcing that …