# Chapter 27: Current and Resistance

Size: px
Start display at page:

Transcription

1 Chapter 7: Current and esistance In this section of the course we will be studying the flow of electric charge, current, in a circuit. We have already seen electric current when we first discussed electric charge. The electric current (i) is defined by how much charge passes a point in space per second: dq i dt The unit of current is amperes (or amps) and one amp is equal to one coulomb per second. For charge to flow in an electrical circuit there must be continuous path from a region of high potential (voltage) to low potential. Current is a scalar quantity. However, for circuit analysis we very often need to know in what direction the current is flowing. Unfortunately, the convention for current flow was made BEFOE it was known that it is the electrons that actually make up the charge carriers. The CONENTION for electrical current is: The current is assumed to be in the direction that a positive charge would move. + - The arrows show the direction of current flow. They are in the direction a positive charge would take as it goes from + terminal of the battery to the terminal. 1

2 Electric Current The net motion of charge carriers is responsible for electric current. In an isolated conductor we know that there is no net motion of electric charge. However, there is quite a bit of motion of individual electrons due to their thermal energy. There is no net transfer of charge because the thermal motion is random and as many electrons that move to the left move to the right. We apply an electric field (or a potential) to cause a net transfer of charge. For example, a battery supplies the electric field (or potential difference) necessary for charge to move in an electric circuit. It is interesting to figure out how fast the electrons that are responsible for current move in a conductor. If n number of charge carriers per volume then the total charge, q, of the carriers in a length of wire L long with cross sectional area A is: qnlae ( e charge on electron1.6x10-19 C) The carriers are moving with speed v d (called the drift velocity) and the time it takes for the carriers to move a distance L is: tl/v d q nale We can relate this to the electric current, i, using: I naevd I 1 j t L / vd The drift velocity is: v d ( ) A ne ne I/A current density j This can be extended to vector form: j nev d

3 Electric Current continued So, how fast do electrons move in typical copper wire? Let s assume we have 1 amp of current and a copper wire with r1mm. v I 1 ( ) d A ne On page 617 HW calculates n for copper: n 8.49x10 8 m -3 j ne v d 1A 1 5 ( ).3 10 m / s ~10 cm/hr! π (10 ) ( )( ) The electrons actually drift rather slowly through the conductor. However, the electric field, or changes in the electric field due to motion of the charges moves very close to the speed of light (3x10 8 m/s) and therefore electricity appears to be instantaneous. 3

4 esistance and esistivity We define the quantity called resistance to be: d/di. The unit of resistance is Ohms (Ω). A very useful electrical circuit element is the resistor. Its universal symbol looks like: We can also talk about a quantity called resistivity, ρ, which is related to the electric field in a conductor and the current density: E ρj Instead of resistivity people speak of conductivity: σ1/ρ. This leads to another relationship: J σe Finally, we can relate resistivity (ρ) to resistance () assuming an isotropic conductor with uniform cross section A: E / L A ρ resistivity is a property of the material J I / A L The resistivity of conductors is very small: 10-8 Ω-m (copper, Al) while the resistivity of insulators is very large: Ω-m (glass). If a material has the property that d/di is a constant, independent of the magnitude and polarity of and I (or E) then that material obeys Ohm s Law. obeys Ohm s law does not obey Ohm s law esistors obey Ohm s law, transistors do not obey ohm s law! HW

5 Power in Electric Circuits We can calculate how the power in an electric circuit depends on, I, and by remembering that the energy (E) to move charge dq through a constant potential difference is: Eq > dedqidt (using Idq/dt) Power is the rate of energy change or PdE/dt so we find: PdE/dtI If we want to calculate the power lost in resistor we can use Ohm s law: I P P I I I( I) I ( ) Example: A Ω resistor has 5 amps of current going through it how much power will be dissipated in the resistor? P()(5) 50 Watts (this resistor will be very hot to the touch). Example: A Ω resistor has 10 volts across it how much power will be dissipated in the resistor? P(10) /()50 Watts 5

### Current and Resistance

Current and Resistance 1 Define the current. Understand the microscopic description of current. Discuss the rat at which the power transfer to a device in an electric current. 2 2-1 Electric current 2-2

### Look over Chapter 26 sections 1-7 Examples 3, 7. Look over Chapter 18 sections 1-5, 8 over examples 1, 2, 5, 8, 9,

Look over Chapter 26 sections 1-7 Examples 3, 7 Look over Chapter 18 sections 1-5, 8 over examples 1, 2, 5, 8, 9, 1)How to find a current in a wire. 2)What the Current Density and Draft Speed are. 3)What

### Notes on Electricity (Circuits)

A circuit is defined to be a collection of energy-givers (batteries) and energy-takers (resistors, light bulbs, radios, etc.) that form a closed path (or complete path) through which electrical current

### Chapter 26 Current and Resistance

Chapter 26 Current and Resistance Electric Current Although an electric current is a stream of moving charges, not all moving charges constitute an electric current. If there is to be an electric current

### Chapter 3: Electric Current and Direct-Current Circuit

Chapter 3: Electric Current and Direct-Current Circuit n this chapter, we are going to discuss both the microscopic aspect and macroscopic aspect of electric current. Direct-current is current that flows

### Electric Current, Resistance and Resistivity. Brief otes

Electric current, resistance and restivity Electric Current, esistance and esistivity In This small e-book we will learn all we need to know about current electricity but in short and then we ll have some

### and in a simple circuit Part 2

Current, Resistance, and Voltage in a simple circuit Part 2 Electric Current Whenever electric charges of like signs move, an electric current is said to exist. Look at the charges flowing perpendicularly

### Direct Current (DC) Circuits

Direct Current (DC) Circuits NOTE: There are short answer analysis questions in the Participation section the informal lab report. emember to include these answers in your lab notebook as they will be

### Direct Currents. We will now start to consider charges that are moving through a circuit, currents. Sunday, February 16, 2014

Direct Currents We will now start to consider charges that are moving through a circuit, currents. 1 Direct Current Current usually consists of mobile electrons traveling in conducting materials Direct

### Notes on Electricity (Circuits)

A circuit is defined to be a collection of energy-givers (active elements) and energy-takers (passive elements) that form a closed path (or complete path) through which electrical current can flow. The

### PHY102 Electricity Course Summary

TOPIC 1 ELECTOSTTICS PHY1 Electricity Course Summary Coulomb s Law The magnitude of the force between two point charges is directly proportional to the product of the charges and inversely proportional

### Chapter 16. Current and Drift Speed. Electric Current, cont. Current and Drift Speed, cont. Current and Drift Speed, final

Chapter 6 Current, esistance, and Direct Current Circuits Electric Current Whenever electric charges of like signs move, an electric current is said to exist The current is the rate at which the charge

### Electric Current. Chapter 17. Electric Current, cont QUICK QUIZ Current and Resistance. Sections: 1, 3, 4, 6, 7, 9

Electric Current Chapter 17 Current and Resistance Sections: 1, 3, 4, 6, 7, 9 Whenever electric charges of like signs move, an electric current is said to exist The current is the rate at which the charge

### Insulators Non-metals are very good insulators; their electrons are very tightly bonded and cannot move.

SESSION 11: ELECTRIC CIRCUITS Key Concepts Resistance and Ohm s laws Ohmic and non-ohmic conductors Series and parallel connection Energy in an electric circuit X-planation 1. CONDUCTORS AND INSULATORS

### Current and Resistance

Chapter 26 Current and Resistance Copyright 26-1 Electric Current As Fig. (a) reminds us, any isolated conducting loop regardless of whether it has an excess charge is all at the same potential. No electric

### Ohm's Law and Resistance

Ohm's Law and Resistance Resistance Resistance is the property of a component which restricts the flow of electric current. Energy is used up as the voltage across the component drives the current through

### Chapter 17. Current and Resistance. Sections: 1, 3, 4, 6, 7, 9

Chapter 17 Current and Resistance Sections: 1, 3, 4, 6, 7, 9 Equations: 2 2 1 e r q q F = k 2 e o r Q k q F E = = I R V = A L R ρ = )] ( 1 [ o o T T + = α ρ ρ V I V t Q P = = R V R I P 2 2 ) ( = = C Q

### Electric Currents and Simple Circuits

-1 Electric Currents and Simple Circuits Electrons can flow along inside a metal wire if there is an E-field present to push them along ( F= qe). The flow of electrons in a wire is similar to the flow

### Ideal wires, Ideal device models, Ideal circuits. Ideal models for circuit elements Wires

Ideal wires, Ideal device models, Ideal circuits Ideal models for circuit elements Wires Currents and Voltages Joints Resistors Voltage sources Current sources. EE 42 Lecture 1 1 Cast of Characters Fundamental

### Test Review Electricity

Name: Date: 1. An operating television set draws 0.71 ampere of current when connected to a 120-volt outlet. Calculate the time it takes the television to consume 3.0 10 5 joules of electric energy. [Show

### What is an Electric Current?

Electric Circuits NTODUCTON: Electrical circuits are part of everyday human life. e.g. Electric toasters, electric kettle, electric stoves All electrical devices need electric current to operate. n this

### Chapter 3: Electric Current And Direct-Current Circuits

Chapter 3: Electric Current And Direct-Current Circuits 3.1 Electric Conduction 3.1.1 Describe the microscopic model of current Mechanism of Electric Conduction in Metals Before applying electric field

### Flow Rate is the NET amount of water passing through a surface per unit time

Electric Current An Analogy Water Flow in a Pipe H 2 0 gallons/minute Flow Rate is the NET amount of water passing through a surface per unit time Individual molecules are bouncing around with speeds of

### DC circuits, Kirchhoff s Laws

DC circuits, Kirchhoff s Laws Alternating Current (AC), Direct Current (DC) DC Circuits Resistors Kirchhoff s Laws CHM6158C - Lecture 2 1 Electric current Movement of electrons in a conductor Examples

### fehmibardak.cbu.tr Temporary Office 348, Mühendislik Fakültesi B Blok

fehmibardak.cbu.tr Temporary Office 348, Mühendislik Fakültesi B Blok 1 Course Progress Introductory level Electrostatic, Coulomb s Law Electric Field, Gauss Law Magnetic field, Maxwell s Equations Current,

### Electric Current. Electric current is the rate of flow of charge through some region of space The SI unit of current is the ampere (A)

Electric Current Electric current is the rate of flow of charge through some region of space The SI unit of current is the ampere (A) 1 A = 1 C / s The symbol for electric current is I Average Electric

### Chapter 3: Current and Resistance. Direct Current Circuits

Chapter 3: Current and Resistance. Direct Current Circuits 3.1. Electric Current 3.2. Resistance and Resistivity 3.3. Ohm s Law and a Microscopic View of Ohm s Law 3.4. Semiconductors and Superconductors

### Electric Current. You must know the definition of current, and be able to use it in solving problems.

Today s agenda: Electric Current. You must know the definition of current, and be able to use it in solving problems. Current Density. You must understand the difference between current and current density,

### Unit 2 Electrical Quantities and Ohm s Law

Electrical Quantities and Ohm s Law Objectives: Define a coulomb. Define an ampere. Define a volt. Define an ohm. Define a watt. Objectives: Compute electrical values using Ohm s law. Discuss basic types

### CHAPTER 1 ELECTRICITY

CHAPTER 1 ELECTRICITY Electric Current: The amount of charge flowing through a particular area in unit time. In other words, it is the rate of flow of electric charges. Electric Circuit: Electric circuit

### ELECTRICITY. Electric Circuit. What do you already know about it? Do Smarty Demo 5/30/2010. Electric Current. Voltage? Resistance? Current?

ELECTRICITY What do you already know about it? Voltage? Resistance? Current? Do Smarty Demo 1 Electric Circuit A path over which electrons travel, out through the negative terminal, through the conductor,

### Chapter 25 Current, Resistance, and Electromotive Force

Chapter 25 Current, Resistance, and Electromotive Force Lecture by Dr. Hebin Li Goals for Chapter 25 To understand current and how charges move in a conductor To understand resistivity and conductivity

### Chapters 24/25: Current, Circuits & Ohm s law Thursday September 29 th **Register your iclickers**

Chapters 24/25: Current, Circuits & Ohm s law Thursday September 29 th **Register your iclickers** Conductors under dynamic conditions Current, current density, drift velocity Ohm s law Types of conductor

### Current and Resistance

Alastair McLean March 10, 2010 Alastair McLean () Current and Resistance March 10, 2010 1 / 21 1 Current and Resistance Learning Objectives New Symbols Current density Drift velocity Electrical Resistance

### Ohm s Law and Electronic Circuits

Production Ohm s Law and Electronic Circuits Page 1 - Cyber Security Class ELECTRICAL CIRCUITS All you need to be an inventor is a good imagination and a pile of junk. -Thomas Edison Page 2 - Cyber Security

### Physics for Scientists & Engineers 2

Review The resistance R of a device is given by Physics for Scientists & Engineers 2 Spring Semester 2005 Lecture 8 R =! L A ρ is resistivity of the material from which the device is constructed L is the

### Chapter 27. Current And Resistance

Chapter 27 Current And Resistance Electric Current Electric current is the rate of flow of charge through some region of space The SI unit of current is the ampere (A) 1 A = 1 C / s The symbol for electric

### Chapter 27 Current and resistance

27.1 Electric Current Chapter 27 Current and resistance 27.2 Resistance 27.3 A Model for Electrical Conduction 27.4 Resistance and Temperature 27.6 Electrical Power 2 27.1 Electric Current Consider a system

### UNIT 5: Electric Current and Direct-Current Circuit (D.C.)

UNT 5: Electric Current Direct-Current Circuit (D.C.) SF07 5. Electric Current, Consider a simple closed circuit consists of wires, a battery a lamp as shown in figure 5.a. F r e E r rea, From the figure,

### Chapter 24: Electric Current

Chapter 24: Electric Current Electric current Electric current is a net flow of electric charge. Quantitatively, current is the rate at which charge crosses a given area. I = dq dt dq = q(n AL)=q(n Av

### Engineering Fundamentals and Problem Solving, 6e

Engineering Fundamentals and Problem Solving, 6e Chapter 17 Electrical Circuits Chapter Objectives Compute the equivalent resistance of resistors in series and in parallel Apply Ohm s law to a resistive

### What are the two types of current? The two types of current are direct current and alternating current.

Electric Current What are the two types of current? The two types of current are direct current and alternating current. Electric Current The continuous flow of electric charge is an electric current.

### Direct-Current Circuits. Physics 231 Lecture 6-1

Direct-Current Circuits Physics 231 Lecture 6-1 esistors in Series and Parallel As with capacitors, resistors are often in series and parallel configurations in circuits Series Parallel The question then

Physics 142 Steady Currents Page 1 Steady Currents If at first you don t succeed, try, try again. Then quit. No sense being a damn fool about it. W.C. Fields Electric current: the slow average drift of

### 10/14/2018. Current. Current. QuickCheck 30.3

Current If QCurrent is the total amount of charge that has moved past a point in a wire, we define the current I in the wire to be the rate of charge flow: The SI unit for current is the coulomb per second,

### Chapter 21 Electric Current and Circuits

Chapter 21 Electric Current and Circuits 1 As an introduction to this chapter you should view the following movie. If you cannot click on the link, then copy it and paste it into your web browser. http://www.ionaphysics.org/movies/vir.mp4

### ELECTRIC CURRENT. Ions CHAPTER Electrons. ELECTRIC CURRENT and DIRECT-CURRENT CIRCUITS

LCTRC CURRNT CHAPTR 25 LCTRC CURRNT and DRCTCURRNT CRCUTS Current as the motion of charges The Ampère Resistance and Ohm s Law Ohmic and nonohmic materials lectrical energy and power ons lectrons nside

### Conceptual Physical Science 6 th Edition

Conceptual Physical Science 6 th Edition Chapter 8: STATIC AND CURRENT ELECTRICITY 1 Chapter 8: STATIC AND CURRENT ELECTRICITY Chapter 8: Read: All Homework: Four problems from the following set: 4, 6,

### Electric currents (primarily, in metals)

Electric currents (primarily, in metals) Benjamin Franklin was experimenting electricity in the mid- XVIII Century. Nobody knew if it was the positive charges or negative charges carrying the current through

### Chapter 24: Electric Current

Chapter 24: Electric Current Current Definition of current A current is any motion of charge from one region to another. Suppose a group of charges move perpendicular to surface of area A. The current

### Electricity

Electricity Electric Charge There are two fundamental charges in the universe. Positive (proton) has a charge of +1.60 x 10-19 C Negative (electron) has a charge of 1.60 x 10-19 C There is one general

### Lesson 8 Electrical Properties of Materials. A. Definition: Current is defined as the rate at which charge flows through a surface:

Lesson 8 Electrical Properties of Materials I. Current I A. Definition: Current is defined as the rate at which charge flows through a surface: + + B. Direction: The direction of positive current flow

### Protons = Charge Electrons = Charge Neutrons = Charge. When Protons = Electrons, atoms are said to be ELECTRICALLY NEUTRAL (no net charge)

QUICK WRITE: For 2 minutes, write the three parts of an atom and what their charges are. Explain what creates an electric charge (positive or negative) on something. Rules - You MUST write for the entire

### Section 1 Electric Charge and Force

CHAPTER OUTLINE Section 1 Electric Charge and Force Key Idea questions > What are the different kinds of electric charge? > How do materials become charged when rubbed together? > What force is responsible

### I depicted in Figure 1. When a current of I amps (A) flows through the resistor, a voltage drop V AB volts (V) appears across the terminals A and B.

ntroduction to DC Circuits v 0.92: September 20, 2018 Gerald ecktenwald gerry@pdx.edu 1 ntroduction Engineers from all disciplines need to have working knowledge of basic electrical circuits. These notes

### AP Physics C - E & M

Slide 1 / 27 Slide 2 / 27 AP Physics C - E & M Current, Resistance & Electromotive Force 2015-12-05 www.njctl.org Slide 3 / 27 Electric Current Electric Current is defined as the movement of charge from

### Coulomb s constant k = 9x10 9 N m 2 /C 2

1 Part 2: Electric Potential 2.1: Potential (Voltage) & Potential Energy q 2 Potential Energy of Point Charges Symbol U mks units [Joules = J] q 1 r Two point charges share an electric potential energy

### Version 001 CIRCUITS holland (1290) 1

Version CIRCUITS holland (9) This print-out should have questions Multiple-choice questions may continue on the next column or page find all choices before answering AP M 99 MC points The power dissipated

### ENGR 2405 Class No Electric Circuits I

ENGR 2405 Class No. 48056 Electric Circuits I Dr. R. Williams Ph.D. rube.williams@hccs.edu Electric Circuit An electric circuit is an interconnec9on of electrical elements Charge Charge is an electrical

### Chapter 33 - Electric Fields and Potential. Chapter 34 - Electric Current

Chapter 33 - Electric Fields and Potential Chapter 34 - Electric Current Electric Force acts through a field An electric field surrounds every electric charge. It exerts a force that causes electric charges

### ECE 2100 Circuit Analysis

ECE 2100 Circuit Analysis Lesson 3 Chapter 2 Ohm s Law Network Topology: nodes, branches, and loops Daniel M. Litynski, Ph.D. http://homepages.wmich.edu/~dlitynsk/ esistance ESISTANCE = Physical property

### PHYSICS FORM 5 ELECTRICAL QUANTITES

QUANTITY SYMBOL UNIT SYMBOL Current I Amperes A Voltage (P.D.) V Volts V Resistance R Ohm Ω Charge (electric) Q Coulomb C Power P Watt W Energy E Joule J Time T seconds s Quantity of a Charge, Q Q = It

### Unit 3 BLM Answers UNIT 3 BLM 3-46

UNIT 3 BLM 3-46 Unit 3 BLM Answers BLM 3-3, Charge Transfer Diagrams 1. Positively charged objects should have more (+) than ( ). Negatively charged objects should have more ( ) than (+). 2. They must

### 16.1 Electrical Current

16.1 Electrical Current Electric Current Electric Current When the ends of an electric conductor are at different electric potentials, charge flows from one end to the other Flow of Charge Charge flows

### CURRENT ELECTRICITY The charge flowing any cross-section per unit time in a conductor is called electric current.

CUENT ELECTICITY Important Points:. Electric Current: The charge flowing any cross-section per unit time in a conductor is called electric current. Electric Current I q t. Current Density: a) The current

### Electron Theory of Charge. Electricity. 1. Matter is made of atoms. Refers to the generation of or the possession of electric charge.

Electricity Refers to the generation of or the possession of electric charge. There are two kinds of electricity: 1. Static Electricity the electric charges are "still" or static 2. Current Electricity

### Chapter 27. Current And Resistance

Chapter 27 Current And Resistance Electric Current Electric current is the rate of flow of charge through some region of space The SI unit of current is the ampere (A) 1 A = 1 C / s The symbol for electric

8 TH GRADE MATHEMATICS: AIM: USING OHM S LAW TO SOLVE MATH PROBLEMS HOME WORK: HANDOUT BY MR. AKOMAH ENCHANCING STUDENTS SKILLS IN INVERESE OPERATION USING OHMS LAW : Students will 1.Become aware of Ohm's

### PHYSICS 570 Master's of Science Teaching. Instructor Richard Sonnenfeld

1 PHYSICS 570 Master's of Science Teaching 1 Electricity Lecture 10 Current, Power, Resistance, and Ohm's Law. Instructor Richard Sonnenfeld mpsonnenfeld@gmail.com 575 835 6434 Big ideas If you know Voltage,

### What does it mean for an object to be charged? What are charges? What is an atom?

What does it mean for an object to be charged? What are charges? What is an atom? What are the components of an atom? Define the following: Electric Conductor Electric Insulator Define the following: Electric

### Chapter 25: Electric Current

Chapter 25: Electric Current Conductors and Charge Carriers Consider a conducting piece of metal: The valence electrons are weakly bound to the nuclei form a fluidlike sea of electrons that can move through

### Section 1: Electric Fields

PHY 132 Outline of Lecture Notes i Section 1: Electric Fields A property called charge is part of the basic nature of protons and electrons. Large scale objects become charged by gaining or losing electrons.

### Circuit Analysis I (ENGR 2405) Chapter 1 Review: Charge, Current, Voltage, Power

Circuit Analysis I (ENGR 2405) Chapter 1 Review: Charge, Current, Voltage, Power What is a circuit? An electric circuit is an interconnection of electrical elements. It may consist of only two elements

### Electroscope Used to are transferred to the and Foil becomes and

Electricity Notes Chapter 17 Section 1: Electric Charge and Forces Electric charge is a variety of independent all with one single name. Electricity is related to, and both (-) and (+) carry a charge.

### EXPERIMENT 12 OHM S LAW

EXPERIMENT 12 OHM S LAW INTRODUCTION: We will study electricity as a flow of electric charge, sometimes making analogies to the flow of water through a pipe. In order for electric charge to flow a complete

### DEVIL PHYSICS THE BADDEST CLASS ON CAMPUS IB PHYSICS

DEL PHYSCS THE BADDEST CLASS ON CAMPUS B PHYSCS TSOKOS LESSON 5-4: ELECTRC CURRENT AND ELECTRC RESSTANCE Reading Activity Questions? Objectives By the end of this class you should be able to: Q State the

### Chapter 27 Current and Resistance 27.1 Electric Current

Chapter 27 Current and esistance 27.1 Electric Current Electric current: dq dt, unit: ampere 1A = 1C s The rate at which charge flows through a surface. No longer have static equilibrium. E and Q can 0

### 1) Two lightbulbs, one rated 30 W at 120 V and another rated 40 W at 120 V, are arranged in two different circuits.

1) Two lightbulbs, one rated 30 W at 120 V and another rated 40 W at 120 V, are arranged in two different circuits. a. The two bulbs are first connected in parallel to a 120 V source. i. Determine the

### Chapter 25 Electric Currents and. Copyright 2009 Pearson Education, Inc.

Chapter 25 Electric Currents and Resistance 25-1 The Electric Battery Volta discovered that electricity could be created if dissimilar metals were connected by a conductive solution called an electrolyte.

### Chapter 27. Current and Resistance

Chapter 27 Current and Resistance Electric Current Most practical applications of electricity deal with electric currents. The electric charges move through some region of space. The resistor is a new

### Chapter 19. Electric Current, Resistance, and DC Circuit Analysis

Chapter 19 Electric Current, Resistance, and DC Circuit Analysis I = dq/dt Current is charge per time SI Units: Coulombs/Second = Amps Direction of Electron Flow _ + Direction of Conventional Current:

### Current. I = ei e = en e Av d. The current, which is Coulomb s per second, is simply

Current The current, which is Coulomb s per second, is simply I = ei e = en e Av d e is the charge is the electron! ne is the density of electrons! A is the cross sectional area of the wire! vd is the

### Chapter 1 Circuit Variables

Chapter 1 Circuit Variables 1.1 Electrical Engineering: An Overview 1.2 The International System of Units 1.3 Circuit Analysis: An Overview 1.4 Voltage and Current 1.5 The Ideal Basic Circuit Element 1.6

### 3 Electric current, resistance, energy and power

3 3.1 Introduction Having looked at static charges, we will now look at moving charges in the form of electric current. We will examine how current passes through conductors and the nature of resistance

### Chapter 18. Direct Current Circuits

Chapter 18 Direct Current Circuits Sources of emf The source that maintains the current in a closed circuit is called a source of emf Any devices that increase the potential energy of charges circulating

### Lecture #2 Charge, Current, Energy, Voltage Power Kirchhoff s Current Law Kirchhoff s Voltage Law

EECS 42 Introduction to Electronics for Computer Science Andrew R. Neureuther Lecture #2 Charge, Current, Energy, Voltage Power Kirchhoff s Current Law Kirchhoff s Voltage Law Corrections Slide 3 and 9

### Resistance Learning Outcomes

Resistance Learning Outcomes Define resistance and give its unit. Solve problems about resistance. State Ohm s Law. HL: Derive the formulas for resistors in series and parallel. Solve problems about resistors

### ELEC 103. Objectives

ELEC 103 Voltage, Current, and Resistance Objectives Define voltage and discuss its characteristics Define current and discuss its characteristics Define resistance and discuss its characteristics Identify

### Electromagnetism Checklist

Electromagnetism Checklist Elementary Charge and Conservation of Charge 4.1.1A Convert from elementary charge to charge in coulombs What is the charge in coulombs on an object with an elementary charge

### CLASS X- ELECTRICITY

Conductor- Insulator: Materia Materials through which electric current cannot pass are called insulators. Electric Circuit: A continuous a CLASS X- ELECTRICITY als through which electric current can pass

### Monday July 14. Capacitance demo slide 19 Capacitors in series and parallel slide 33 Elmo example

Monday July 14 Lecture 5 Capacitance demo slide 19 Capacitors in series and parallel slide 33 Elmo example Lecture 6 Currents and esistance Lecture 9 Circuits Wear Microphone 1 3 Lecture 6 Current and

### Lecture 7.1 : Current and Resistance

Lecture 7.1 : Current and Resistance Lecture Outline: Current and Current Density Conductivity and Resistivity Resistance and Ohm s Law Textbook Reading: Ch. 30.3-30.5 Feb. 26, 2013 1 Announcements By

### Resistance Learning Outcomes. Resistance Learning Outcomes. Resistance

Resistance Learning Outcomes Define resistance and give its unit. Solve problems about resistance. State Ohm s Law. HL: Derive the formulas for resistors in series and parallel. Solve problems about resistors

### 2. Basic Components and Electrical Circuits

1 2. Basic Components and Electrical Circuits 2.1 Units and Scales The International System of Units (SI) defines 6 principal units from which the units of all other physical quantities can be derived

### Physics 11b Lecture #8

Physics 11b Lecture #8 Current and Resistance S&J Chapter 27 Administravia First midterm this Thursday Covers up to and including capacitance Lectures #1 #7, textbook chapters 23 26 Five problems Problem

### Gas discharges. Current flow of electric charge. Electric current (symbol I) L 26 Electricity and Magnetism [3] examples of electrical discharges

L 26 Electricity and Magnetism [3] Electric circuits what conducts electricity what doesn t t conduct electricity Current voltage and resistance Ohm s s Law Heat in a resistor power loss Making simple

### Closed loop of moving charges (electrons move - flow of negative charges; positive ions move - flow of positive charges. Nucleus not moving)

Unit 2: Electricity and Magnetism Lesson 3: Simple Circuits Electric circuits transfer energy. Electrical energy is converted into light, heat, sound, mechanical work, etc. The byproduct of any circuit

### Electricity. From the word Elektron Greek for amber

Electricity From the word Elektron Greek for amber Electrical systems have two main objectives: To gather, store, process, transport information & Energy To distribute and convert energy Electrical Engineering