ELC - Introduction to Electric Circuits

Electric Circuits Overview

Introduction

It is easy to take electricity for granted; just plug it in and it plays. It is difficult to imagine that slightly more than 100 years ago electrical power distribution was just beginning; Edison and Westinghouse were figuratively waging war over what type of electricity, DC or AC, would power this nation. As often happens in science and engineering, history finds that each has its advantages and are both extensively utilized today. In this unit we will discover the meaning and some applications of electric potential, commonly known as voltage and how it powers some simple circuits. This will set the stage into further study in the next and following courses in physics for manipulating electric potential to serve the varied devices that our modern society has come to depend upon.

Essential Questions

1. What is charge?
2. How do charges interact in free space?
3. How do charges interact within conductors?
4. What is electric potential?
5. What is an electric circuit?
6. How is energy transferred and transformed in an electric circuit?
7. What is the relationship among potential, current and resistance?
8. What characterizes a series circuit?
9. What characterizes a parallel circuit?
10. How are conservation principles of charge and energy related to electric circuits?

Key Terms

1. alternating current - the flow of electric charge periodically reversing direction.
2. circuit - an electrical network that has a closed loop giving a return path for the current.
3. conductor - an object or type of material, usually a metal, which permits the flow of electric charges in one or more directions.
4. current - a flow of electric charge.
5. direct current - the flow of electric charge that is only in one direction.
6. electrostatic - a branch of physics that deals with the phenomena and properties of stationary or slow-moving electric charges with no acceleration.
7. insulator - a material whose internal electric charges do not flow freely, and which therefore does not conduct an electric current, under the influence of an electric field.
8. Ohm's law - law stating that the current through a conductor between two points is directly proportional to the potential difference across the two points, equated through the proportionality constant, resistance.
9. parallel circuit - a circuit connected by conductors in such a manner that the potential difference across any circuit element is equal to the potential difference across all other circuit elements.
10. potential difference - a scalar quantity, also known as voltage, representing potential energy per unit charge.
11. resistance - the opposition to the passage of an electric current through a material. Resistance is a function of the objects geometry and resistivity.
12. resistivity - the inherent property of a material, independent of its geometry, which quantifies how strongly the material opposes the flow of electric current.
13. series circuit - a circuit connected by conductors in such a manner that the current through any element must be equal to the current through all other circuit elements.
14. voltage - a scalar quantity, also known as potential difference, representing potential energy per unit charge.

IMAGES CREATED BY GAVS