Effect of a Dielectric on a Capacitor

This demonstration shows the effect of adding a dielectric to a capacitor. As a dielectric is added to a capacitor, the voltage decreases and the capacitance increases.

* Equipment seen in the video may vary from equipment used in ND Demonstrations. See information and images below for ND equipment and setup.

Setup:

Place the equipment on the lab table. Connect the webcam to the projector system and set it up to view the electroscope. Set the plates of the capacitor about two centimeters apart.

Remove the top plate of the electrophorus. Rub the fur on the bottom plate of the electrophorus. Return the top plate to the base and touch the back of the top plate to ground it. Take the top plate by the insulated handle and touch one of the capacitor plates. The electroscope will show a voltage across the plates.

Place a dielectric between the capacitor plates and see the voltage decrease on the electroscope. Remove the dielectric and the electroscope returns to its original value.

Notes:

None

Courses Used In:

• PHY 10320

• PHy 20435

• PHY 30220

Discussion and Polling Questions:

Coming Soon

Equipment Needed:

• Parallel Plate Capacitor

• Electroscope

• Two Banana Cables

• Dielectric Materials

• Electrohorus

• Fur

• Ring Stand

• Webcam