Electric Fields and Potential

Electric Field Patterns

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Visualization of various electrostatic fields on OHP.

Charges and Fields simulation

Faraday Ice Pail and Cage

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Used in conjunction with an electrometer, this ensemble provides quantitative measurements for a variety of electrostatic experiments.

Electric Force on Neutral Object

[M | t+ |★★★]
A neutral conductor (or dielectric) experiences a torque—but no net force—when placed in a uniform electric field (it does experience a net force in a non-uniform field).
[In-Depth Description]

Coke Can Attraction

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A neutral coke can rolls across the lecture table as it is attracted to a charged rod. A case of a neutral object in the presence of a non-uniform electric field.

Surface Charge Densities

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Charged, conductive solids can be probed to determine charge densities ... used with Faraday ice pail and cage.

Field Emission

[L | t | ★★★]
A metallic cone with a sharp point placed near the Van de Graaff generator prevents charge from building up on the dome of the generator—models the principles of the lightning rod.

Benjamin Franklin's Thunder House

[M | t+ | ★★★]
A replica of Franklin's Thunder House demonstating the efficacy of his invention—the lightning rod. The class will get a charge out of this one.
[In-Depth Description]

Electric Potential of Sphere

[L | t++ | ★★★]
The potential of a conducting sphere placed in an electric field is found to be constant, notwithstanding the fact that the sphere is polarized with excess electrons on one side and a deficit on the other.

Force on an Electric Dipole

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A freely suspended electric dipole aligns itself with the electric field (provided by two large, charged capacitor plates).

Electrostatic Shielding

[M | t++ | ★★★★]
How does shielding work? Is it a two-way street and work both ways? Can electric fields not penetrate metals? What's going on? This sequence of demonstrations addresses these questions.
[In-Depth Description]

Charge Inside Hollow Conductor

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Charged, hollow conductor is probed to demonstrate the absence of electric charges inside.

Walk-In Faraday Cage

[L | t+ | ★★★★]
Sit in it and get raised to high potentials.
[In-Depth Description]

Shielding from Radio Waves

[M | t | ★★]
Place a portable radio inside an aluminzed plastic bag to supress reception.


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A lawn sprinkler style rotor with pointed ends becomes an electrostatic motor when brought to high potentials.


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Selection of different capacitor types for quantitative measurements as well as show 'n tell.

Giant Capacitor

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Parallel plate capacitor (1m dia.) with variable plate separation.
[In-Depth Description]

Capacitance of Human Body

[s | t+ | ★★]
Your capacitance can be determined by putting your body in parallel with a capacitor of known value.
[In-Depth Description]

Dissectible Capacitor

[M | t++ | ★★]
Charge a capacitor, take it apart, ground the plates, reassemble it, and discharge it with a bang. Where was that electrical engergy hiding?

Force on a Conductor

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A suspended conductor is pulled into a parallel plate capacitor when charged.

Energy Stored in a Capacitor

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Capacitor drives motor which raises a mass.
[In-Depth Description]

Explosive Capacitor Discharge

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The energy stored in a capacitor is dramatized by discharging it through a wire shorted across the capacitor.
[In-Depth Description]

One Farad

[S/M | t+ | —]
State-of-the-art capacitor makes impressive charge storage container; with suitable light bulb, RC is visibly long!

Contact Us

Mailing Address: Lecture Demonstration Services, Science Center, Rm B-08A, 1 Oxford Street, Cambridge, MA 02138
Campus Location: Science Center B-08A | Tel: (617) 495-5824 | Email: scidemos-at-fas.harvard.edu