Electrostatics with Conductors


This section contains documents created from scanned original files and other
documents that could not be made accessible to screen reader software. A "#"
symbol is used to denote such documents.

Video Clips

Video RealVideo®
9:20 minutes (41:41 - 51:01)

Explanation of how a Van de Graaff generator works, with a demonstration of making one manually.

Prior Knowledge: None
Instructor: Prof. Walter Lewin
Back to Top
Video RealVideo®
6:01 minutes (44:02 - 50:03)

A power supply generated from falling water. Not explained until a later lecture.

Prior Knowledge: None
Instructor: Prof. Walter Lewin
Back to Top
Video RealVideo®
4:48 minutes (20:33 - 25:21)

Electric field inside a conductor is always zero. Charge on a conductor is distributed on the surface. Example of positive charge placed on a heart-shaped conductor.

Prior Knowledge: Conductors (7:15 of video lecture 1)
Instructor: Prof. Walter Lewin
Back to Top
Video RealVideo®
6:29 minutes (25:21 - 31:50)

Charge placed on a hollow conductor will be distributed only on the outside surface. Demonstration using a metal paint can showing that there is no electric field inside a charged hollow conductor. Electric shielding is defined.

Prior Knowledge: Conductors (7:15 of video lecture 1, 20:33 of video lecture 5)
Instructor: Prof. Walter Lewin
Back to Top
Video RealVideo®
4:38 minutes (31:50 - 36:28)

No electric field inside a hollow conductor that is placed in an electric field. Electric shielding and the Faraday cage are defined.

Prior Knowledge: Conductors (7:15 of video lecture 1, 20:33 of video lecture 5)
Instructor: Prof. Walter Lewin
Back to Top
Video RealVideo®
6:05 minutes (37:07 - 43:12)

If charge placed inside a hollow conductor, there will be an opposite charge distributed on inside surface and an equal charge on the outside surface of the conductor.

Prior Knowledge: Conductors (7:15 of video lecture 1, 20:33 of video lecture 5)
Instructor: Prof. Walter Lewin
Back to Top
Video RealVideo®
6:46 minutes (43:12 - 49:58)

Using a paint can to show that a hollow conductor in an electric field has charge distributed on the outside but no charge on the inside surface. Bringing a radio into a giant Faraday cage to demonstrate electric shielding. Getting inside a charged Faraday cage to show there is no charge on the inside surface.

Prior Knowledge: Conductors (7:15 of video lecture 1, 20:33 of video lecture 5)
Instructor: Prof. Walter Lewin
Back to Top
Video RealVideo®
6:29 minutes (0:00 - 6:29)

Finding the charge density and electric field for conductors that are not completely symmetric.

Prior Knowledge: Conductors (7:15 of video lecture 1, 20:33 of video lecture 5)
Instructor: Prof. Walter Lewin
Back to Top
Video RealVideo®
2:36 minutes (6:29 - 9:05)

Charging up a metal cooking pot to show that there is higher charge density where the curvature is greater on a conductor.

Prior Knowledge: Conductors (7:15 of video lecture 1, 20:33 of video lecture 5)
Instructor: Prof. Walter Lewin
Back to Top
Video RealVideo®
8:03 minutes (27:24 - 35:27)

How ionized water and gravity generate the large potential differences in the Kelvin Water Dropper.

Prior Knowledge: Kelvin Water Dropper (44:02 of video lecture 10)
Instructor: Prof. Walter Lewin
Back to Top
Video RealVideo®
11:51 minutes (35:27 - 47:18)

Repositioning the components of the Kelvin Water Dropper to demonstrate other interesting behavior.

Prior Knowledge: Kelvin Water Dropper (44:02 of video lecture 10)
Instructor: Prof. Walter Lewin
Back to Top

Lecture Notes

Document PDF
Page 4 to page 14

Introduction of conductors and their properties, including the relevance of equipotentials.

Prior Knowledge: Gauss's Law (OT4.2)
Instructors: Prof. John Belcher, Dr. Peter Dourmashkin, Prof. Robert Redwine, Prof. Bruce Knuteson, Prof. Gunther Roland, Prof. Bolek Wyslouch, Dr. Brian Wecht, Prof. Eric Katsavounidis, Prof. Robert Simcoe, Prof. Joseph Formaggio, Andy Neely, Matthew Strafuss, Prof. Eric Hudson, Dr. Sen-Ben Liao
Back to Top
Document PDF
Page 4 to page 10

Hollow conductors and how they allow for shielding of electromagnetic field.

Prior Knowledge: Conductors (OT4.3)
Instructors: Prof. John Belcher, Dr. Peter Dourmashkin, Prof. Robert Redwine, Prof. Bruce Knuteson, Prof. Gunther Roland, Prof. Bolek Wyslouch, Dr. Brian Wecht, Prof. Eric Katsavounidis, Prof. Robert Simcoe, Prof. Joseph Formaggio, Andy Neely, Matthew Strafuss, Prof. Eric Hudson, Dr. Sen-Ben Liao
Back to Top
Document PDF#
Page 8 to page 13

Conductors and insulators defined; e-fields inside conductors; uniqueness theorem and potential inside cavities.

Prior Knowledge: Poisson's equation
Instructor: Prof. Gabriella Sciolla
Back to Top

Online Textbook Chapter

Document PDF
Page 15 to page 22

Definition of conductors and their properties; examples of how to determine charge on a conductor and electric field and potential around a conductor.

Prior Knowledge: Electric Potential of Charge Distributions (OT3.4), Gauss's Law (OT4.2)
Instructors: Prof. John Belcher, Dr. Peter Dourmashkin, Prof. Robert Redwine, Prof. Bruce Knuteson, Prof. Gunther Roland, Prof. Bolek Wyslouch, Dr. Brian Wecht, Prof. Eric Katsavounidis, Prof. Robert Simcoe, Prof. Joseph Formaggio, Andy Neely, Matthew Strafuss, Prof. Eric Hudson, Dr. Sen-Ben Liao
Back to Top
Document PDF
Page 22 to page 24

Determining force on a surface of a conductor; derivation of electrostatic pressure.

Prior Knowledge: Conductors (OT4.3), Gauss's Law (OT4.2)
Instructors: Prof. John Belcher, Dr. Peter Dourmashkin, Prof. Robert Redwine, Prof. Bruce Knuteson, Prof. Gunther Roland, Prof. Bolek Wyslouch, Dr. Brian Wecht, Prof. Eric Katsavounidis, Prof. Robert Simcoe, Prof. Joseph Formaggio, Andy Neely, Matthew Strafuss, Prof. Eric Hudson, Dr. Sen-Ben Liao
Back to Top

Practice Problems

Document PDF
Problem 1

3-part Gauss's law problem; determining qualitative charge distributions for different locations of the charge.

Prior Knowledge: None
Instructor: Prof. Walter Lewin
Back to Top
Document PDF
Problem 5

Calculating current, charge, capacitance delivered to Van de Graaff generator.

Prior Knowledge: None
Instructor: Prof. Walter Lewin
Back to Top
Document PDF
Problem 1

Explaining creation of sparks in the apparatus.

Prior Knowledge: None
Instructor: Prof. Walter Lewin
Back to Top
Document PDF
Problem 2

Drawing and explaining electric field near ellipsoid conductor.

Prior Knowledge: None
Instructors: Dr. Peter Dourmashkin, Prof. Gunther Roland
Back to Top
Document PDF
Problem 3

Explaining equipotentiality; comparing E-fields near spheres.

Prior Knowledge: None
Instructors: Dr. Peter Dourmashkin, Prof. Gunther Roland
Back to Top

Exam Questions

Document PDF
Problem 2

Explaining charged object interaction with uncharged conductors and insulators.

Prior Knowledge: None
Instructors: Dr. Peter Dourmashkin, Prof. Gunther Roland
Back to Top

Java Applets

Java Applet Java Applet
Requires Java Virtual Machine

Applet demonstrating a method for charging a conductor without ever making direct contact.

Prior Knowledge: None
Instructors: Prof. John Belcher, Dr. Peter Dourmashkin, Prof. Michael Feld, Prof. Eric Hudson, Prof. John Joannopoulos, Prof. Bruce Knuteson, Dr. George Stephans
Back to Top
Java Applet Java Applet
Requires Java Virtual Machine

Applet simulating the behavior of charges in a charged conducting slab.

Prior Knowledge: None
Instructors: Prof. John Belcher, Dr. Peter Dourmashkin, Prof. Michael Feld, Prof. Eric Hudson, Prof. John Joannopoulos, Prof. Bruce Knuteson, Dr. George Stephans
Back to Top