Chapter 21 Electric Current and Direct Current Circuits


 Nicholas Day
 4 years ago
 Views:
Transcription
1 Chapter 21 Electric Current and Direct Current Circuits 1
2 Overview of Chapter 21 Electric Current and Resistance Energy and Power in Electric Circuits Resistors in Series and Parallel Kirchhoff s Rules Circuits Containing Capacitors RC Circuits 2
3 211 Electric Current Electric current is the flow of electric charge from one place to another. Electric circuit: A closed path through which charge can flow, returning to its starting point. 3
4 Battery has a potential difference between terminals 211 Electric Current Chemical reactions separate electrons from atoms Analogy 4  Current to flows through the flashlight bulb similar to someone lifting water which flows through the paddle wheel.
5 211 Electric Current A battery that is disconnected from any circuit has an electric potential difference between its terminals called the electromotive force (emf) Remember despite its name, the emf is an electric potential, not a force. Amount of work it takes to move a charge ΔQ from one terminal to the other is: 5
6 211 Electric Current Current flows from the positive terminal to the negative Decided before it was realized that electrons are negatively charged. The electrons move the other way 6
7 211 Electric Current Actual motion of electrons along a wire is quite slow Electrons spend most of their time bouncing around randomly with small velocity component  Opposite to the direction of the current. The electric signal propagates much more quickly 7
8 212 Resistance and Ohm s Law Wires present some resistance to the motion of electrons. Ohm s law relates the voltage to the current: Be careful Ohm s law is not a universal law and is only useful for certain materials (which include most metallic conductors). 8
9 212 Resistance and Ohm s Law Solving for the resistance, we find: The units of resistance, volts per ampere, are called ohms: 9
10 212 Resistance and Ohm s Law Two wires of the same length and diameter will have different resistances if they are made of different materials. Property of a material is called the resistivity. 10
11 212 Resistance and Ohm s Law The difference between insulators, semiconductors, is quantified by resistivity.. 11
12 212 Resistance and Ohm s Law In general.. Resistance of materials goes up as the temperature goes up, due to thermal effects. This property can be used in thermometers. Resistivity decreases as the temperature decreases Class of materials called superconductors Resistivity drops suddenly to zero at a finite temperature, called the critical temperature T C. 12
13 212 Resistance and Ohm s Law Superconductors in action. The ATLAS experiment at the LHC. MRI machines. 13
14 213 Energy and Power in Electric Circuits When a charge moves across a potential difference, its potential energy changes: Therefore, the power it takes to do this is Remember 14
15 213 Energy and Power in Electric Circuits In materials for which Ohm s law holds, the power can also be written: This power mostly dissipates as heat inside a resistive material 15
16 213 Energy and Power in Electric Circuits When the electric company sends you a bill, your usage is quoted in kilowatthours (kwh). They are charging you for energy use, and kwh are a measure of energy. 16
17 214 Resistors in Series and Parallel Resistors connected end to end are said to be in series. They can be replaced by a single equivalent resistance without changing the current in the circuit. 17
18 214 Resistors in Series and Parallel Relation due to current through the series resistors being the same for each.. 18
19 214 Resistors in Series and Parallel Resistors are in parallel when they are across the same potential difference They can again be replaced by a single equivalent resistance.. 19
20 214 Resistors in Series and Parallel Relation due to potential difference across parallel resistors being the same for each.. 20
21 214 Resistors in Series and Parallel If a circuit is more complex: Start with combinations of resistors that are either purely in series or in parallel. Replace these with their equivalent resistances; as you go on you will be able to replace more and more of them. 21
22 215 Kirchhoff s Rules Even more complex circuits cannot be broken down into series and parallel pieces. Kirchhoff s rules are needed. The junction rule is a consequence of charge conservation; the loop rule is a consequence of energy conservation. 22
23 215 Kirchhoff s Rules The junction rule: At any junction, the current entering the junction must equal the current leaving it. 23
24 215 Kirchhoff s Rules The loop rule: The algebraic sum of the potential differences around a closed loop must be zero (it must return to its original value at the original point). 24
25 Using Kirchhoff s rules: 215 Kirchhoff s Rules The variables for which you are solving are the currents through the resistors. You need as many independent equations as you have variables to solve for. You will need both loop and junction rules. 25
26 216 Circuits Containing Capacitors Capacitors can also be connected in series or in parallel. When capacitors are connected in parallel, the potential difference across each one is the same. 26
27 216 Circuits Containing Capacitors Therefore, the equivalent capacitance is the sum of the individual capacitances: 27
28 216 Circuits Containing Capacitors Capacitors connected in series do not have the same potential difference across them. They do all carry the same charge. The total potential difference is the sum of the potential differences across each one. 28
29 216 Circuits Containing Capacitors Therefore, the equivalent capacitance is Capacitors in series combine like resistors in parallel, and vice versa. 29
30 217 RC Circuits Circuit containing only batteries and capacitors Charge appears almost instantaneously on the capacitors when the circuit is connected. If the circuit contains resistors as well Not the case Known as a RC circuit 30
31 217 RC Circuits It can be shown that the charge on the capacitor increases as: Here, τ is the time constant of the circuit: And is the final charge on the capacitor, Q. 31
32 217 RC Circuits Here is the charge vs. time for an RC circuit: 32
33 217 RC Circuits It can be shown that the current in the circuit has a related behavior: 33
34 Answer: a) 14 C Answer: b) 8.8 x electrons 34
35 Hint: Resistivity of silver is 1.59 x 108 Ω m Answer: 0.5 Ω 35
36 36 Answer: 33 Ω
37 Note on Kirchoff s laws Loop rule: Sum of the potential differences around a closed loop must be zero  ε = +15 V + I R 3 R 1 What does this mean? R 2 EMF adds a potential difference to current Resistors take it away ε + V 1 +V 2 +V 3 = 0 ε IR 1 IR 2 IR 3 = 0 37
38 Note on Kirchoff s laws ε T ε T I I ε ε R 1 R 1 R 2 R 2 ε IR 1 IR 2 +ε 1 = 0 ε IR 1 IR 2 ε 2 = 0 38
39 39 Answer: A
40 40
41 41 Answer: 6.1 kω
Lecture Outline Chapter 21. Physics, 4 th Edition James S. Walker. Copyright 2010 Pearson Education, Inc.
Lecture Outline Chapter 21 Physics, 4 th Edition James S. Walker Chapter 21 Electric Current and Direct Current Circuits Units of Chapter 21 Electric Current Resistance and Ohm s Law Energy and Power
More informationChapter 21 Electric Current and Direct Current Circuits
Chapter 21 Electric Current and Direct Current Circuits Units of Chapter 21 Electric Current Resistance and Ohm s Law Energy and Power in Electric Circuits Resistors in Series and Parallel Kirchhoff s
More informationChapter 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
More informationWhat 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
More informationChapter 18 Electric Currents
Chapter 18 Electric Currents 1 The Electric Battery Volta discovered that electricity could be created if dissimilar metals were connected by a conductive solution called an electrolyte. This is a simple
More informationAP Physics C. Electric Circuits III.C
AP Physics C Electric Circuits III.C III.C.1 Current, Resistance and Power The direction of conventional current Suppose the crosssectional area of the conductor changes. If a conductor has no current,
More informationElectric Currents. Resistors (Chapters 2728)
Electric Currents. Resistors (Chapters 2728) Electric current I Resistance R and resistors Relation between current and resistance: Ohm s Law Resistivity ρ Energy dissipated by current. Electric power
More informationElectric Charge. Electric Charge ( q ) unbalanced charges positive and negative charges. n Units Coulombs (C)
Electric Charge Electric Charge ( q ) unbalanced charges positive and negative charges n Units Coulombs (C) Electric Charge How do objects become charged? Types of materials Conductors materials in which
More informationPhysics 1214 Chapter 19: Current, Resistance, and DirectCurrent Circuits
Physics 1214 Chapter 19: Current, Resistance, and DirectCurrent Circuits 1 Current current: (also called electric current) is an motion of charge from one region of a conductor to another. Current When
More informationChapter 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
More informationChapter 28. Direct Current Circuits
Chapter 28 Direct Current Circuits Circuit Analysis Simple electric circuits may contain batteries, resistors, and capacitors in various combinations. For some circuits, analysis may consist of combining
More informationphysics 4/7/2016 Chapter 31 Lecture Chapter 31 Fundamentals of Circuits Chapter 31 Preview a strategic approach THIRD EDITION
Chapter 31 Lecture physics FOR SCIENTISTS AND ENGINEERS a strategic approach THIRD EDITION randall d. knight Chapter 31 Fundamentals of Circuits Chapter Goal: To understand the fundamental physical principles
More informationLecture #3. Review: Power
Lecture #3 OUTLINE Power calculations Circuit elements Voltage and current sources Electrical resistance (Ohm s law) Kirchhoff s laws Reading Chapter 2 Lecture 3, Slide 1 Review: Power If an element is
More information4 Electric circuits. Serial and parallel resistors V 3 V 2 V Serial connection of resistors:
4 lectric circuits PHY67 Spring 006 Serial and parallel resistors Serial connection of resistors: As the current I through each of serially connected resistors is the same, one can use Ohm s law and write...
More informationChapter 20 Electric Circuits
Chapter 0 Electric Circuits Chevy olt  Electric vehicle of the future Goals for Chapter 9 To understand the concept of current. To study resistance and Ohm s Law. To observe examples of electromotive
More informationNotes on Electricity (Circuits)
A circuit is defined to be a collection of energygivers (batteries) and energytakers (resistors, light bulbs, radios, etc.) that form a closed path (or complete path) through which electrical current
More informationChapter 19 Lecture Notes
Chapter 19 Lecture Notes Physics 2424  Strauss Formulas: R S = R 1 + R 2 +... C P = C 1 + C 2 +... 1/R P = 1/R 1 + 1/R 2 +... 1/C S = 1/C 1 + 1/C 2 +... q = q 0 [1e t/(rc) ] q = q 0 e t/(rc τ = RC
More informationCapacitance. A different kind of capacitor: Work must be done to charge a capacitor. Capacitors in circuits. Capacitor connected to a battery
Capacitance The ratio C = Q/V is a conductor s self capacitance Units of capacitance: Coulomb/Volt = Farad A capacitor is made of two conductors with equal but opposite charge Capacitance depends on shape
More informationChapter 17 Electric Current and Resistance Pearson Education, Inc.c
Chapter 17 Electric Current and Resistance 2010 Pearson Education, Inc.c 1 Units of Chapter 17 Batteries and Direct Current Current and Drift Velocity Resistance and Ohm s Law Electric Power 2010 Pearson
More informationPhysics 2135 Exam 2 October 20, 2015
Exam Total / 200 Physics 2135 Exam 2 October 20, 2015 Printed Name: Rec. Sec. Letter: Five multiple choice questions, 8 points each. Choose the best or most nearly correct answer. 1. A straight wire segment
More informationDirect Current Circuits. February 18, 2014 Physics for Scientists & Engineers 2, Chapter 26 1
Direct Current Circuits February 18, 2014 Physics for Scientists & Engineers 2, Chapter 26 1 Kirchhoff s Junction Rule! The sum of the currents entering a junction must equal the sum of the currents leaving
More informationClass 8. Resistivity and Resistance Circuits. Physics 106. Winter Press CTRLL to view as a slide show. Class 8. Physics 106.
and Circuits and Winter 2018 Press CTRLL to view as a slide show. Last time we learned about Capacitance Problems ParallelPlate Capacitors Capacitors in Circuits Current Ohm s Law and Today we will learn
More informationVersion 001 CIRCUITS holland (1290) 1
Version CIRCUITS holland (9) This printout should have questions Multiplechoice questions may continue on the next column or page find all choices before answering AP M 99 MC points The power dissipated
More informationAP Physics C  E & M
AP Physics C  E & M Current and Circuits 20170712 www.njctl.org Electric Current Resistance and Resistivity Electromotive Force (EMF) Energy and Power Resistors in Series and in Parallel Kirchoff's
More informationAP Physics C  E & M
Slide 1 / 27 Slide 2 / 27 AP Physics C  E & M Current, Resistance & Electromotive Force 20151205 www.njctl.org Slide 3 / 27 Electric Current Electric Current is defined as the movement of charge from
More informationELECTRIC CURRENTS D R M A R T A S T A S I A K D E P A R T M E N T O F C Y T O B I O L O G Y A N D P R O T E O M I C S
ELECTRIC CURRENTS D R M A R T A S T A S I A K D E P A R T M E N T O F C Y T O B I O L O G Y A N D P R O T E O M I C S lecture based on 2016 Pearson Education, Ltd. The Electric Battery Electric Current
More informationChapter 25 Electric Currents and. Copyright 2009 Pearson Education, Inc.
Chapter 25 Electric Currents and Resistance 251 The Electric Battery Volta discovered that electricity could be created if dissimilar metals were connected by a conductive solution called an electrolyte.
More informationMasteringPhysics: Assignment Print View. Problem 30.50
Page 1 of 15 Assignment Display Mode: View Printable Answers phy260s08 homework 13 Due at 11:00pm on Wednesday, May 14, 2008 View Grading Details Problem 3050 Description: A 15cmlong nichrome wire is
More informationChapter 2. Engr228 Circuit Analysis. Dr Curtis Nelson
Chapter 2 Engr228 Circuit Analysis Dr Curtis Nelson Chapter 2 Objectives Understand symbols and behavior of the following circuit elements: Independent voltage and current sources; Dependent voltage and
More information6. In a dry cell electrical energy is obtained due to the conversion of:
1. If a wire of uniform area of cross section is cut into two halves (equal in size), the resistivity of each part will be: a) Halved. b) Doubled. c) Becomes four times its initial value. d) Remains the
More informationElectric Currents and Circuits
Nicholas J. Giordano www.cengage.com/physics/giordano Chapter 19 Electric Currents and Circuits Marilyn Akins, PhD Broome Community College Electric Circuits The motion of charges leads to the idea of
More informationIn this unit, we will examine the movement of electrons, which we call CURRENT ELECTRICITY.
Recall: Chemistry and the Atom! What are the 3 subatomic Where are they found in the particles? atom? What electric charges do they have? How was a positive ion created? How was a negative ion created?
More informationScience Olympiad Circuit Lab
Science Olympiad Circuit Lab Key Concepts Circuit Lab Overview Circuit Elements & Tools Basic Relationships (I, V, R, P) Resistor Network Configurations (Series & Parallel) Kirchhoff s Laws Examples Glossary
More informationELECTRIC CURRENT. Ions CHAPTER Electrons. ELECTRIC CURRENT and DIRECTCURRENT 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
More informationPhysics 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
More informationAC vs. DC Circuits. Constant voltage circuits. The voltage from an outlet is alternating voltage
Circuits AC vs. DC Circuits Constant voltage circuits Typically referred to as direct current or DC Computers, logic circuits, and battery operated devices are examples of DC circuits The voltage from
More informationElectric Current & DC Circuits
Electric Current & DC Circuits Circuits Click on the topic to go to that section Conductors Resistivity and Resistance Circuit Diagrams Measurement EMF & Terminal Voltage Kirchhoff's Rules Capacitors*
More informationChapter 28. Direct Current Circuits
Chapter 28 Direct Current Circuits Electromotive Force An electromotive force device, or emf device, is a source of constant potential. The emf describes the work done per unit charge and has units of
More informationM. C. Escher: Waterfall. 18/9/2015 [tsl425 1/29]
M. C. Escher: Waterfall 18/9/2015 [tsl425 1/29] Direct Current Circuit Consider a wire with resistance R = ρl/a connected to a battery. Resistor rule: In the direction of I across a resistor with resistance
More informationWhat 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.
More informationChapter 27. Circuits
Chapter 27 Circuits 1 1. Pumping Chagres We need to establish a potential difference between the ends of a device to make charge carriers follow through the device. To generate a steady flow of charges,
More informationR R V I R. Conventional Current. Ohms Law V = IR
DC Circuits opics EMF and erminal oltage esistors in Series and in Parallel Kirchhoff s ules EMFs in Series and in Parallel Capacitors in Series and in Parallel Ammeters and oltmeters Conventional Current
More informationChapter 3: Electric Current and DirectCurrent Circuit
Chapter 3: Electric Current and DirectCurrent Circuit n this chapter, we are going to discuss both the microscopic aspect and macroscopic aspect of electric current. Directcurrent is current that flows
More informationNotes on Electricity (Circuits)
A circuit is defined to be a collection of energygivers (active elements) and energytakers (passive elements) that form a closed path (or complete path) through which electrical current can flow. The
More informationCapacitance, Resistance, DC Circuits
This test covers capacitance, electrical current, resistance, emf, electrical power, Ohm s Law, Kirchhoff s Rules, and RC Circuits, with some problems requiring a knowledge of basic calculus. Part I. Multiple
More informationEXPERIMENT 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
More informationDirectCurrent Circuits. Physics 231 Lecture 61
DirectCurrent Circuits Physics 231 Lecture 61 esistors in Series and Parallel As with capacitors, resistors are often in series and parallel configurations in circuits Series Parallel The question then
More informationCHAPTER 16,18,19 TEST REVIEW
AP PHYSICS Name: Period: Date: Points: 58 Score: IB Curve: DEVIL PHYSICS BADDEST CLASS ON CAMPUS 50 Multiple Choice 45 Single Response 5 MultiResponse Free Response 3 Short Free Response 2 Long Free Response
More informationElectric charge is conserved the arithmetic sum of the total charge cannot change in any interaction.
Electrostatics Electric charge is conserved the arithmetic sum of the total charge cannot change in any interaction. Electric Charge in the Atom Atom: Nucleus (small, massive, positive charge) Electron
More informationChapter 3: Electric Current And DirectCurrent Circuits
Chapter 3: Electric Current And DirectCurrent Circuits 3.1 Electric Conduction 3.1.1 Describe the microscopic model of current Mechanism of Electric Conduction in Metals Before applying electric field
More informationPHY102 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
More informationPhysics 115. General Physics II. Session 24 Circuits Series and parallel R Meters Kirchoff s Rules
Physics 115 General Physics II Session 24 Circuits Series and parallel R Meters Kirchoff s Rules R. J. Wilkes Email: phy115a@u.washington.edu Home page: http://courses.washington.edu/phy115a/ 5/15/14 Phys
More informationFlow 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
More informationCurrent 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 21 Electric current 22
More informationChapter 26 DirectCurrent Circuits
Chapter 26 DirectCurrent Circuits 1 Resistors in Series and Parallel In this chapter we introduce the reduction of resistor networks into an equivalent resistor R eq. We also develop a method for analyzing
More information1) 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
More informationBy Mir Mohammed Abbas II PCMB 'A' CHAPTER FORMULAS & NOTES. 1. Current through a given area of a conductor is the net charge passing
Formulae For u CURRENT ELECTRICITY 1 By Mir Mohammed Abbas II PCMB 'A' 1 Important Terms, Definitions & Formulae CHAPTER FORMULAS & NOTES 1. Current through a given area of a conductor is the net charge
More informationChapter 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
More informationMonday 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
More informationElectric Current & DC Circuits How to Use this File Electric Current & DC Circuits Click on the topic to go to that section Circuits
Slide 1 / 127 Slide 2 / 127 Electric Current & DC Circuits www.njctl.org Slide 3 / 127 How to Use this File Slide 4 / 127 Electric Current & DC Circuits Each topic is composed of brief direct instruction
More informationELECTRIC CIRCUITS. Checklist. Exam Questions
ELECTRIC CIRCUITS Checklist Make sure you can. State Ohm's law in words. Determine relationship between current, potential difference and resistance at constant temperature using a simple circuit Draw,
More informationDC Circuits. Circuits and Capacitance Worksheet. 10 Ω resistance. second? on the sodium is the same as on an electron, but positive.
Circuits and Capacitance Worksheet DC Circuits 1. A current of 1.30 A flows in a wire. How many electrons are flowing past any point in the wire per second? 2. What is the current in amperes if 1200 Na
More informationChapter 25 Electric Currents and Resistance. Copyright 2009 Pearson Education, Inc.
Chapter 25 Electric Currents and Resistance Units of Chapter 25 The Electric Battery Electric Current Ohm s Law: Resistance and Resistors Resistivity Electric Power Units of Chapter 25 Power in Household
More informationCircuits. Electric Current & DC Circuits. Slide 1 / 127. Slide 2 / 127. Slide 3 / 127. Slide 4 / 127. Slide 5 / 127. Slide 6 / 127
Slide 1 / 127 Slide 2 / 127 New Jersey Center for Teaching and Learning Electric Current & DC Circuits www.njctl.org Progressive Science Initiative This material is made freely available at www.njctl.org
More informationPhysics Tutorial  Currents and Circuits
Question 1: Ion Channels Physics Tutorial  Currents and Circuits The biochemistry that takes place inside cells depends on various elements that are dissolved in water as ions. The ions enter cells through
More informationKirchhoff's Laws and Circuit Analysis (EC 2)
Kirchhoff's Laws and Circuit Analysis (EC ) Circuit analysis: solving for I and V at each element Linear circuits: involve resistors, capacitors, inductors Initial analysis uses only resistors Power sources,
More informationElectricity
Electricity Electric Charge There are two fundamental charges in the universe. Positive (proton) has a charge of +1.60 x 1019 C Negative (electron) has a charge of 1.60 x 1019 C There is one general
More informationPhysics 212 Midterm 2 Form A
1. A wire contains a steady current of 2 A. The charge that passes a cross section in 2 s is: A. 3.2 1019 C B. 6.4 1019 C C. 1 C D. 2 C E. 4 C 2. In a Physics 212 lab, Jane measures the current versus
More informationTactics Box 23.1 Using Kirchhoff's Loop Law
PH203 Chapter 23 solutions Tactics Box 231 Using Kirchhoff's Loop Law Description: Knight/Jones/Field Tactics Box 231 Using Kirchhoff s loop law is illustrated Learning Goal: To practice Tactics Box 231
More informationPHYS 1444 Section 003 Lecture #12
PHYS 1444 Section 003 Lecture #12 Monday, Oct. 10, 2005 EMF and Terminal Voltage Resisters in series and parallel Kirchhoff s Rules EMFs in series and parallel RC Circuits Today s homework is homework
More information= e = e 3 = = 4.98%
PHYS 212 Exam 2  Practice Test  Solutions 1E In order to use the equation for discharging, we should consider the amount of charge remaining after three time constants, which would have to be q(t)/q0.
More informationand 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
More informationEngineering 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
More informationSuperconductors A class of materials and compounds whose resistances fall to virtually zero below a certain temperature, T C T C is called the critical temperature The graph is the same as a normal metal
More informationChapters 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
More information2. 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
More informationUnit 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
More informationSPS Presents: A Cosmic Lunch!
SPS Presents: A Cosmic Lunch! Who: Dr. Brown will be speaking about Evolution of the Elements: from Periodic table to Standard Model and Beyond! When: October 7 th at am Where: CP 79 (by the front office)
More informationChapter 26 & 27. Electric Current and Direct Current Circuits
Chapter 26 & 27 Electric Current and Direct Current Circuits Electric Current and Direct Current Circuits Current and Motion of Charges Resistance and Ohm s Law Energy in Electric Circuits Combination
More information10/14/2018. 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,
More informationIntroduction. Prelab questions: Physics 1BL KIRCHOFF S RULES Winter 2010
Introduction In this lab we will examine more complicated circuits. First, you will derive an expression for equivalent resistance using Kirchhoff s Rules. Then you will discuss the physics underlying
More informationCURRENT ELECTRICITY The charge flowing any crosssection per unit time in a conductor is called electric current.
CUENT ELECTICITY Important Points:. Electric Current: The charge flowing any crosssection per unit time in a conductor is called electric current. Electric Current I q t. Current Density: a) The current
More informationA Review of Circuitry
1 A Review of Circuitry There is an attractive force between a positive and a negative charge. In order to separate these charges, a force at least equal to the attractive force must be applied to one
More informationSIMPLE D.C. CIRCUITS AND MEASUREMENTS Background
SIMPLE D.C. CICUITS AND MEASUEMENTSBackground This unit will discuss simple D.C. (direct current current in only one direction) circuits: The elements in them, the simple arrangements of these elements,
More informationChapter 25 Electric Currents and Resistance. Copyright 2009 Pearson Education, Inc.
Chapter 25 Electric Currents and Resistance 254 Resistivity Example 255: Speaker wires. Suppose you want to connect your stereo to remote speakers. (a) If each wire must be 20 m long, what diameter copper
More informationPhysics 2401 Summer 2, 2008 Exam II
Physics 2401 Summer 2, 2008 Exam II e = 1.60x1019 C, m(electron) = 9.11x1031 kg, ε 0 = 8.845x1012 C 2 /Nm 2, k e = 9.0x10 9 Nm 2 /C 2, m(proton) = 1.67x1027 kg. n = nano = 109, µ = micro = 106, m
More informationENERGY AND TIME CONSTANTS IN RC CIRCUITS By: Iwana Loveu Student No Lab Section: 0003 Date: February 8, 2004
ENERGY AND TIME CONSTANTS IN RC CIRCUITS By: Iwana Loveu Student No. 416 614 5543 Lab Section: 0003 Date: February 8, 2004 Abstract: Two charged conductors consisting of equal and opposite charges forms
More informationChapter 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:
More informationChapter 25 Current Resistance, and Electromotive Force
Chapter 25 Current Resistance, and Electromotive Force 1 Current In previous chapters we investigated the properties of charges at rest. In this chapter we want to investigate the properties of charges
More informationPhysics 202: Lecture 5, Pg 1
Resistance Resistors Series Parallel Ohm s law Electric Circuits Current Physics 132: Lecture e 15 Elements of Physics II Kirchhoff s laws Agenda for Today Physics 202: Lecture 5, Pg 1 Electric Current
More informationPhysics 7B1 (A/B) Professor Cebra. Winter 2010 Lecture 2. Simple Circuits. Slide 1 of 20
Physics 7B1 (A/B) Professor Cebra Winter 2010 Lecture 2 Simple Circuits Slide 1 of 20 Conservation of Energy Density In the First lecture, we started with energy conservation. We divided by volume (making
More informationPHY232 Spring 2008 Jon Pumplin (Original ppt courtesy of Remco Zegers) Direct current Circuits
PHY232 Spring 2008 Jon Pumplin http://www.pa.msu.edu/~pumplin/phy232 (Original ppt courtesy of Remco Zegers) Direct current Circuits So far, we have looked at systems with only one resistor PHY232 Spring
More informationLABORATORY 4 ELECTRIC CIRCUITS I. Objectives
LABORATORY 4 ELECTRIC CIRCUITS I Objectives to be able to discuss potential difference and current in a circuit in terms of electric field, work per unit charge and motion of charges to understand that
More informationChapter 18. Direct Current Circuits II
Chapter 18 Direct Current Circuits II So far A circuit consists of threefour elements: Electromotive force/power supply/battery capacitors, resistors inductors Analyzed circuits with capacitors or resistors
More informationCHAPTER 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
More informationElectric 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
More informationElectromotive Force. The electromotive force (emf), ε, of a battery is the maximum possible voltage that the battery can provide between its terminals
Direct Current When the current in a circuit has a constant magnitude and direction, the current is called direct current Because the potential difference between the terminals of a battery is constant,
More informationXII PHYSICS [CURRENT ELECTRICITY] CHAPTER NO. 13 LECTURER PHYSICS, AKHSS, K.
XII PHYSICS LECTURER PHYSICS, AKHSS, K affan_414@live.com https://promotephysics.wordpress.com [CURRENT ELECTRICITY] CHAPTER NO. 13 CURRENT Strength of current in a conductor is defined as, Number of coulombs
More informationProblem Solving 8: Circuits
MASSACHUSETTS INSTITUTE OF TECHNOLOGY Department of Physics OBJECTIVES Problem Solving 8: Circuits 1. To gain intuition for the behavior of DC circuits with both resistors and capacitors or inductors.
More informationPower lines. Why do birds sitting on a highvoltage power line survive?
Power lines At large distances, the resistance of power lines becomes significant. To transmit maximum power, is it better to transmit high V, low I or high I, low V? (a) high V, low I (b) low V, high
More information