Basic Electricity
EAS 199A Lecture Notes: Basic Electricity
Fall 2011
This course module introduces the basic physical models by which we explain the flow of electricity. The Bohr model of an atom – a nucleus surrounded by shells of electrons traveling in discrete orbits – is presented. Electrical current is described as a flow of electrons. Ohm’s law – the relationship between voltage, current and electrical resistance – is introduced. Learning Objectives Understanding the basic principles of electricity is a foundational skill for all branches of engineering. Understanding electricity is required to use electrical sensors, switches, digital and analog devices, and microcontrollers. In this course, students will use breadboards to assemble electronic components for reading data from sensors and controlling switches, lights, motors and other actuators. The larger purpose is to learn how to incorporate electronic components into solutions to engineering design problems. Successful completion of this module will enable students to 1. Link basic model of an atom to the flow of electricity; 2. Understand the definition of fundamental quantities related to the flow of electricity: coulomb, amp, volt, ohm, joule and watt; 3. Apply Ohm’s Law to single electronic components and to simple circuits. Definition of Electricity and Electrical Charge According to the Concise Oxford English Dictionary, revised 10th edition, the first definition of electricity is a form of energy resulting from the existence of charged particles (such as electrons or protons), either statically as an accumulation of charge or dynamically as a current.
Thus, to describe electricity we must introduce the idea of positive and negative electrical charge, which is stored energy associated with particles – electrons and protons. It is tempting to think of electrons and protons as discrete, hard objects, like marbles. However, the physical reality is much more complicated. Electrons are highly mobile
Fall 2011
This course module introduces the basic physical models by which we explain the flow of electricity. The Bohr model of an atom – a nucleus surrounded by shells of electrons traveling in discrete orbits – is presented. Electrical current is described as a flow of electrons. Ohm’s law – the relationship between voltage, current and electrical resistance – is introduced. Learning Objectives Understanding the basic principles of electricity is a foundational skill for all branches of engineering. Understanding electricity is required to use electrical sensors, switches, digital and analog devices, and microcontrollers. In this course, students will use breadboards to assemble electronic components for reading data from sensors and controlling switches, lights, motors and other actuators. The larger purpose is to learn how to incorporate electronic components into solutions to engineering design problems. Successful completion of this module will enable students to 1. Link basic model of an atom to the flow of electricity; 2. Understand the definition of fundamental quantities related to the flow of electricity: coulomb, amp, volt, ohm, joule and watt; 3. Apply Ohm’s Law to single electronic components and to simple circuits. Definition of Electricity and Electrical Charge According to the Concise Oxford English Dictionary, revised 10th edition, the first definition of electricity is a form of energy resulting from the existence of charged particles (such as electrons or protons), either statically as an accumulation of charge or dynamically as a current.
Thus, to describe electricity we must introduce the idea of positive and negative electrical charge, which is stored energy associated with particles – electrons and protons. It is tempting to think of electrons and protons as discrete, hard objects, like marbles. However, the physical reality is much more complicated. Electrons are highly mobile