Definition, with examples of capacitance for spheres and for parallel plate capacitors.

How to make a small parallel plate capacitor with a large capacitance. Finding the amount of energy stored in a parallel plate capacitor.

Starting to charge a large capacitor to a potential difference of 3000 V.

Explanation of the concepts behind a camera flash, with a demonstration using several capacitors and a light bulb.

Examples of Professor Edgerton's high speed photography, including images of a bullet fired through a light bulb and a balloon being popped. Brief discussion of strobe lights and their uses.

After 15 minutes of charging, the capacitor is quickly discharged over a fuse with impressive results.

Exploring work required to separate two oppositely charged parallel plates, with definition of field energy density and potential energy stored in an electric field.

Using an actual parallel plate capacitor to show that positive work must be done to increase the distance between the two plates.

The effects of increasing the separation between the plates of a capacitor.

The effects of increasing the separation between the plates of a capacitor that is still connected to a power supply.

Effects of area, separation distance, and dielectric constant on the capacitance of a parallel plate capacitor.

Definition and demonstration of a Leyden Jar.

Finding the electric field, potential difference, capacitance, and electrostatic potential energy of a parallel plate capacitor.

Demonstration of the Leyden Jar, with explanation of the physics behind the unexpected result.

Introduction to capacitance; spherical and parallel plate capacitors.

Work done to build up charge on a capacitor and the energy stored in a capacitor; energy density of the electric field.

Capacitance and units; definition of capacitor; capacitance of sphere, parallel-plate, spherical, cylindrical capacitors.

Leyden jars and Wimshurst machine; dielectrics; energy stored by E-field in capacitor.

Capacitance in series and in parallel; applications and problems.

Introduction of capacitance and examples of calculating capacitance for parallel plate, cylindrical and spherical capacitors.

Potential energy stored in a capacitor, and the energy density of the electric field.

Capacitors in series and parallel circuits; calculating equivalent capacitance.

Find the equivalent capacitance for a set of capacitors connected in parallel and in series. Solution is included after problem.

Find the capacitance of a parallel plate capacitor filled with two different dielectrics. Solution is included after problem.

Find the capacitance of a spherical capacitor filled with two different dielectrics. Solution is included after problem.

A spring is connected to one side of a parallel plate capacitor; find the amount that the spring is stretched when the capacitor is charged. Solution is included after problem.

Find the electrostatic force and pressure on the plates of a parallel plate capacitor.

Find the equivalent capacitance and the charges on each capacitor for a combination of capacitors in different switch configurations.

Identify qualitatively how the voltage, charge and stored energy of a parallel plate capacitor change when the plate separation is increased.

How do potential difference and charge change when the distance between plates in a capacitor is increased, with and without a battery connected. How does the energy stored in the system change?

Find the electric field, potential difference, capacitance, and charge distribution on a spherical capacitor. Solution is included after problem.

4-part capacitor problem; finding voltages across capacitors for different switch configurations.

Solution (PDF)

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

Solution (PDF)

5-part problem; finding V, stored energy, work to move plates; inserting dielectric.

Solution (PDF)^#

Comparison of capacitors; showing that with narrow gaps, these capacitors can be approximated as parallel-plate capacitors.

Solution (PDF)

4-part problem; finding voltage, stored energy; explaining conservation of energy in different cases.

Solution (PDF)^#

Force on electron; balancing electric and magnetic forces.

Solution (PDF)

Showing that an electric field does not abruptly drop to 0 at capacitor edge.

Solution (PDF)

5-part problem; finding charge, potential energy, and electric potential.

Solution (PDF)^#

4-part problem; finding E-field, trajectories for particle; computing kinetic energy.

Determining energy stored in parallel-plate capacitor with and without dielectric.

Solution (PDF)^#

Applet simulating the behavior of the charges inside the plates of a parallel plate capacitor.

Applet simulating the behavior of a conducting sphere placed between the plates of a parallel plate capacitor as it is being charged.