Start learning today, and be successful in your academic & professional career. Start Today!

• ## Study Guides

### Start Learning Now

Our free lessons will get you started (Adobe Flash® required).

### Membership Overview

• *Ask questions and get answers from the community and our teachers!
• Practice questions with step-by-step solutions.
• Track your course viewing progress.
• Learn at your own pace... anytime, anywhere!

### More on Filled Capacitors

• An electric field E exerts a torque on an electric dipole of diploe moment p. The torque is p*E*sin(theta), where theta is the angle between the E-field and the dipole moment vector. The torque tends to align the dipole with the field.
• The potential energy of an electric dipole placed in an electric field is

U = –p.E = -p*E*cos(theta).

• When a parallel plate capacitor is filled with a dielectric (insulator) of dielectric constant K, the dielectric becomes polarized (a dipole moment is induced in the dielectric). This, in turn, causes a reduction in the value of E by K, and a corresponding increase in the value of the capacitance by K.
• Examples that show how to calculate the capacitance of a parallel plate capacitor if it is partially filled with a metal or a dielectric are given in the lecture.

### More on Filled Capacitors

Lecture Slides are screen-captured images of important points in the lecture. Students can download and print out these lecture slide images to do practice problems as well as take notes while watching the lecture.

• Intro 0:00
• Electric Dipole is an Electric Field : Torque 0:13
• Magnitude of Dipole
• Starts to Rotate
• Force qe to the Right
• Finding the Torque
• Electric Dipole is an Electric Field : Potential Energy 13:56
• Electric Field Try's to Rotate
• Object on Center of Earth
• Applying Torque Equal and Opposite
• Water Molecule 25:43
• Carbon Molecules
• Net Dipole Moment is Zero
• Induced Dipole Moment
• Filled Capacitor 35:27
• Empty Capacitor with Charge on it
• Inserting a Dielectric
• Capacitor Partially Filled with Metallic Slab 44:33
• Capacitor with Slab of Distance 'd'
• Capacitor Partially Filled with a Dielectric Slab 51:59
• Change in Potential Difference
• Example 1: Parallel Plate Capacitor
• Example 2: Conducting Slab