# Ch 13: Potential and Capacitance in Physics

### About This Chapter

## Potential and Capacitance - Chapter Summary and Learning Objectives

In this chapter, you'll learn how an everyday item, like a battery, converts and stores electrical energy. Using easy-to-understand visuals, the instructor will explain the concept of electric potential, or how groups of tightly packed charged particles interact with each other to do work. You'll also find out how voltage is used to measure electric potential and how much work is accomplished by charged particles in an electrical circuit.

Through the videos on capacitance, you can learn about the different types of electrical components that can store an electrical charge. Ohm's Law will be discussed, including the relationship shared by electrical current, resistance and voltage. When you've finished with the chapter, you should understand:

- The relationship between an electric force and an electric field
- How voltage sources can transform different forms of energy into electrical energy
- The theory of electric potential, including charge collections, measurements and differences
- Capacitance and capacitors, including their parts and how they store energy
- Ohm's Law as it relates to electricity
- The electrical potential of cylinders and spheres

Video | Objectives |
---|---|

Electric Field and the Movement of Charge | Identify and apply the relation between electric force and electric field. |

Voltage Sources: Energy Conversion and Examples | Discuss batteries and how they convert chemical energy into electrical potential energy. Identify the generator as an example of a common voltage source. |

Electric Potential | Explain and use the theory of electric potential energy to solve conservation of energy problems. |

Electric Potential: Charge Collections and Volt Unit | Discuss charge collections and how a charged particle has the potential to do work. Explain the volt as a unit of electrical potential. |

Electric Potential Difference | Describe and calculate the electric potential difference between two points in a uniform electric field, and indicate which point is at the higher potential. |

Capacitance | Define capacitance and the unit of capacitance, and explain how it relates to charge and voltage. Identify the factors that determine capacitance. Solve parallel-plate capacitor problems. |

Combinations of Capacitors | Identify the principal parts of a capacitor. Discuss the advantages of and differences between the basic types of fixed capacitors and variable capacitors. Calculate total capacitance in parallel and series capacitance circuits. |

Energy Stored in a Capacitor | Describe the construction of a capacitor and how charge is stored. Explain the capacitor time constant in relationship to DC charging and discharging and how the capacitor charges and discharges when AC is applied. |

Ohm's Law: Definition and Relationship Between Voltage, Current and Resistance | Discuss how voltage, current and resistance are related, as indicated by Ohm's Law. |

The Potential of a Sphere | Examine the energy potential of a sphere. |

The Potential of a Cylinder | Examine the energy potential of a cylinder. |

### 1. Electric Field & the Movement of Charge

After watching this video, you will be able to explain what an electric field is, draw electric field lines and vectors for charged particles, and complete calculations involving electric fields. A short quiz will follow.

### 2. Voltage Sources: Energy Conversion and Examples

We use them every day, but no one really gives them much thought. What are we talking about? Why, voltage sources, of course! Batteries and generators are two of the most common sources of voltage that power our daily lives. We'll look at them in detail to see how they work.

### 3. Electric Potential Energy: Definition & Formula

After watching this video, you will be able to explain what electric potential energy is and use an equation to solve electric potential energy problems involving point charges. A short quiz will follow.

### 4. Electric Potential: Charge Collections and Volt Unit

In this lesson, we'll find out that electric charges can be rather lazy until something motivates them to get work done. Find out what gives electric charges the potential to do work and how we measure that potential with something called voltage.

### 5. Finding the Electric Potential Difference Between Two Points

After watching this video, you will be able to explain what electric potential difference is and calculate the electric potential difference between two points in a uniform electric field. A short quiz will follow.

### 6. What is Capacitance? - Definition, Equation & Examples

Capacitors are used to store and quickly release large amounts of electrical energy. In this lesson, we will learn how capacitors are created and used and how your body can function as a capacitor.

### 7. Capacitance: Units & Formula

After watching this lesson, you will be able to explain what a capacitor is, define capacitance, and solve simple problems using capacitance equations. A short quiz will follow.

### 8. Fixed & Variable Capacitors: Parts & Types

Capacitors are devices that store electrical energy. In this lesson, we will explore the various types of capacitors, how they work, and how to calculate equivalent capacitance.

### 9. Capacitors: Construction, Charging & Discharging

Electrical circuits have several components, each of which must be understood for the system to work. We're going to check out capacitors in this lesson and see how they can be used to control an electric current.

### 10. Ohm's Law: Definition & Relationship Between Voltage, Current & Resistance

Did you know that electrical current is affected by the voltage and resistance in a circuit? In this lesson, we'll use Ohm's law, which tells us how current, voltage, and resistance are related, as we work through several electric circuit examples.

### 11. The Potential of a Sphere

After watching this lesson, you will be able to explain what electric potential is, state and use the equation for the potential of a sphere, and plot a graph of electric potential with radius. A short quiz will follow.

### 12. The Potential of a Cylinder

After watching this video, you will be able to explain what electric potential is and solve problems using an expression for the electric potential of a cylinder. In AP Physics C, you should be able to derive the expression. A short quiz will follow.

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### Other Chapters

Other chapters within the Physics: High School course

- Introduction to Physics
- Vectors in Physics
- Kinematics in Physics
- Newton's Laws in Physics
- Work, Energy, & Power in Physics
- Linear Momentum in Physics
- Circular Motion and Gravitation in Physics
- Physics Lab Experiments: Motion
- Oscillations in Physics
- Waves, Sound, and Light
- Physics Lab Experiments: Matter & Light
- Electrical Forces and Fields in Physics
- Direct Current Circuits in Physics
- Magnetism in Physics
- Physics Lab Experiments: Electricity
- Thermal Physics & Thermodynamics
- Teaching Resources for High School Physics