Chapter 19 Lecture Notes


 Hugh Lambert
 3 years ago
 Views:
Transcription
1 Chapter 19 Lecture Notes Physics Strauss Formulas: R S = R 1 + R C P = C 1 + C /R P = 1/R 1 + 1/R /C S = 1/C 1 + 1/C q = q 0 [1e t/(rc) ] q = q 0 e t/(rc τ = RC 1. RESISTORS IN A CIRCUIT We will discuss electric circuits that have components connected in series and/or parallel. Series circuits are in connected in a straight line and have the same current through them. Parallel circuits have the same voltage drop across them. 1.1 Series Wiring Suppose two resistors are connected in series. The current going through each resistor is the same so V = IR 1 + IR 2 = I(R 1 + R 2 ) = IR s If circuit elements have no wire junctions between them, then they have the same current flowing through them and they are in series. To solve problems with simple circuits with resistors in series or parallel, first determine the equivalent resistance of the circuit, and then the total current flowing out of the battery. Problem: (a) What is the current flowing through a 3Ω, 6Ω, and 9Ω resistor in series when connected to a 12 V battery? (b) What is the voltage drop across each resistor? The equivalent resistance is 18 Ω which is greater than the resistance of any single resistor. We draw equivalent circuits with fewer resistors. 1.2 Parallel Wiring In a parallel circuit the voltage across each resistor is the same, so I = I 1 + I 2 = V/R 1 + V/R 2 =V(1/R 1 + 1/R 2 ) = V(1/R P ) In general, 1/R P = 1/R 1 + 1/R 2 + 1/R Problem: (a) What is the total current in a circuit if a 3Ω, 6Ω, and 9Ω resistor are connected in parallel to a 12 V battery? (b) What is the current in each resistor? 1
2 Note how the resistance of resistors in parallel is less than the resistance of any single resistor. 1.3 Parallel and Series Together (Equivalent Circuits) If I have resistors in parallel and in series, then I just take a step by step process to reduce this to an equivalent circuit. Problem: What is the equivalent resistance of this circuit? R 3 R 1 R 2 R 4 R 1 = 2 Ω R 3 = 5 Ω R 2 = 4 Ω R 4 = 10 Ω Demonstration/Problem: How many amps run through a tungsten wire when it is hooked up in series to a 100 watt light bulb and 600 watt heater that are in parallel? We can put many resistors together and often still reduce them to a single resistor. How can you rearrange the following diagram? All resistors having the same resistance. 2. KIRCHOFF S RULES Sometimes the circuit is too complicated to reduce to a single resistor, especially if there is more than one battery in the circuit. Then we use a set of rules, called Kirchoff s Rules, for determining the current through a circuit. 1. Junction Rule. The sum of the magnitudes of the currents directed into a junction equals the sum of the magnitudes of the currents directed out of the junction. (Conservation of charge) 2
3 2. Loop Rule. Around any closed loop, the sum of the potential drops equals the sum of the potential rises.. (Conservation of energy) How to Use Kirchoff s Rules: 1. Draw the circuit and draw currents with an arrow in every separate branch of the circuit. A branch is a section where the current does not change. 2. Apply the junction rule to enough junctions so that every current is used at least once. 3. Apply the loop rule to enough closed loops so that each current appears at least once. Remember the sign convention for the potential changes: Going across an battery is a plus sign if going from negative to positive and a minus sign if going from positive to negative. (Plus if going in normal direction of current.) Going across a resistor is a plus sign if going against the current and a minus sign if going with the current. (Minus if going in normal direction of current.) Problem: Find the current and power in the 3 Ω resistor. What is the current in the other two resistors? 6 Ω I 3 I 2 6 Ω 12 V I 1 3 Ω 3 V 3. TERMINAL VOLTAGE A real battery has some internal resistance. So if I were to draw a real battery it would consist of a perfect battery and a resistor. I can treat this just like two separate components when I use Kirchoff s laws or equivalent resistance. However, when I hook up to the battery I do not quite get the entire potential from the battery. Instead I get something slightly smaller. Problem: An ideal battery has a voltage of 9.0 volts and an internal resistance of 0.5 Ω. When it is drawing 0.3 amps, what is the terminal voltage? 3
4 4. CAPACITORS IN A CIRCUIT 4.1 Parallel When capacitors are in parallel, the total charge is the sum of the charge on each one, so... Q = Q 1 +Q 2 = C 1 V + C 2 V = V(C 1 + C 2 ) = C P V so C P = C 1 + C U = 1/2 C P V Series When capacitors are in series, the charge on each one is the same, so... V=Q/C 1 + Q/C 2 = Q(1/C 1 + 1/C 2 ) = QC s so 1/ C s = 1/C 1 + 1/C So, equivalent circuits for capacitors is done the same as for resistors, except that they combine differently. 5. RESISTORS AND CAPACITORS IN A CIRCUIT (RC CIRCUIT) If you attach a battery to a capacitor, the charge starts to build up on the capacitor. How fast it build up is given by the equation Q = Q 0 [1e t/(rc) ] where Q is the amount of charge on the capacitor at a time t, and Q 0 is the total amount of charge that the capacitor will hold. Since V = QC, this can also be written as V =V 0 [1e t/(rc) ] to determine the amount of voltage on the capacitor at any time. The value e is the natural logarithm. It is a transcendental number like π and it equals It can be found on most scientific calculators. y=e z. RC=τ is called the time constant. It is the time it takes for the capacitor to charge to 1/e of its total charge, or about 63.2%. The total charge on the capacitor is still given by Q 0 =CV. When discharging a capacitor, we disconnect the battery and let the charge flow of the capacitor, and we find Q = Q 0 e t/(rc) or in terms of voltage V = V 0 e t/(rc) and RC=τ is the time it takes for the capacitor to lose 63.2% of its charge. What if R is very small or 0, then e t/(rc) is zero and the charging and discharging happens instantaneously. 4
5 Problem : How long does it take for 50% of the maximum charge to be deposited on this circuit when the switch is closed. The resistor is 2 million ohms. and each capacitor is 10 nf. 6. ELECTRICAL SAFETY AND GROUNDING In a three prong outlet, the third prong makes a path of less resistance from the casing to the ground. Any current will flow through the third prong rather than through another body with more resistance. 5
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:
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 informationClicker Session Currents, DC Circuits
Clicker Session Currents, DC Circuits Wires A wire of resistance R is stretched uniformly (keeping its volume constant) until it is twice its original length. What happens to the resistance? 1) it decreases
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 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 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 informationLab 10: DC RC circuits
Name: Lab 10: DC RC circuits Group Members: Date: TA s Name: Objectives: 1. To understand current and voltage characteristics of a DC RC circuit 2. To understand the effect of the RC time constant Apparatus:
More informationExam 3PHYS 102S14
Name: Exam 3PHYS 102S14 Multiple Choice Identify the choice that best completes the statement or answers the question. 1. Which of these statements is always true? a. resistors in parallel have the
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 informationPhysics 102: Lecture 7 RC Circuits
Physics 102: Lecture 7 C Circuits Physics 102: Lecture 7, Slide 1 C Circuits Circuits that have both resistors and capacitors: K Na Cl C ε K ε Na ε Cl S With resistance in the circuits, capacitors do not
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 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 informationChapter 6 DIRECT CURRENT CIRCUITS. Recommended Problems: 6,9,11,13,14,15,16,19,20,21,24,25,26,28,29,30,31,33,37,68,71.
Chapter 6 DRECT CURRENT CRCUTS Recommended Problems: 6,9,,3,4,5,6,9,0,,4,5,6,8,9,30,3,33,37,68,7. RESSTORS N SERES AND N PARALLEL  N SERES When two resistors are connected together as shown we said that
More informationChapter 21 Electric Current and Direct Current Circuits
Chapter 21 Electric Current and Direct Current Circuits 1 Overview of Chapter 21 Electric Current and Resistance Energy and Power in Electric Circuits Resistors in Series and Parallel Kirchhoff s Rules
More informationChapter 26 Examples : DC Circuits Key concepts:
Chapter 26 Examples : DC Circuits Key concepts: Internal resistance : battery consists of some idealized source of voltage (called the electromotive force, or EMF, which uses the symbol ξ) and an effective
More informationRC Circuits (32.9) Neil Alberding (SFU Physics) Physics 121: Optics, Electricity & Magnetism Spring / 1
(32.9) We have only been discussing DC circuits so far. However, using a capacitor we can create an RC circuit. In this example, a capacitor is charged but the switch is open, meaning no current flows.
More informationCircuits Capacitance of a parallelplate capacitor : C = κ ε o A / d. (ρ = resistivity, L = length, A = crosssectional area) Resistance : R = ρ L / A
k = 9.0 x 109 N m2 / C2 e = 1.60 x 1019 C ε o = 8.85 x 1012 C2 / N m2 Coulomb s law: F = k q Q / r2 (unlike charges attract, like charges repel) Electric field from a point charge : E = k q / r2 ( towards
More informationLaboratory 7: Charging and Discharging a Capacitor Prelab
Phys 132L Fall 2018 Laboratory 7: Charging and Discharging a Capacitor Prelab Consider a capacitor with capacitance C connected in series to a resistor with resistance R as shown in Fig. 1. Theory predicts
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 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 informationCh 28DC Circuits! 1.) EMF & Terminal Voltage! 9.0 V 8.7 V 8.7 V. V =! " Ir. Terminal Open circuit internal! voltage voltage (emf) resistance" 2.
Ch 28DC Circuits! 1.) EMF & Terminal Voltage! 9.0 V 8.7 V 8.7 V V =! " Ir Terminal Open circuit internal! voltage voltage (emf) resistance" 2.) Resistors in series! One of the bits of nastiness about
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 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 informationLecture 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 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 informationCircuits Gustav Robert Kirchhoff 12 March October 1887
Welcome Back to Physics 1308 Circuits Gustav Robert Kirchhoff 12 March 1824 17 October 1887 Announcements Assignments for Thursday, October 18th:  Reading: Chapter 28.128.2, 28.4  Watch Video: https://youtu.be/39vkt4cc5nu
More informationElectrical Engineering Fundamentals for NonElectrical Engineers
Electrical Engineering Fundamentals for NonElectrical Engineers by Brad Meyer, PE Contents Introduction... 3 Definitions... 3 Power Sources... 4 Series vs. Parallel... 9 Current Behavior at a Node...
More informationCAPACITORS / ENERGY STORED BY CAPACITORS / CHARGING AND DISCHARGING
PHYSICS A2 UNIT 4 SECTION 3: CAPACITANCE CAPACITORS / ENERGY STORED BY CAPACITORS / CHARGING AND DISCHARGING # Question CAPACITORS 1 What is current? Current is the rate of flow of charge in a circuit
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 informationCircuits. David J. Starling Penn State Hazleton PHYS 212
Invention is the most important product of man s creative brain. The ultimate purpose is the complete mastery of mind over the material world, the harnessing of human nature to human needs.  Nikola Tesla
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 informationGreek Letter Omega Ω = Ohm (Volts per Ampere)
) What is electric current? Flow of Electric Charge 2) What is the unit we use for electric current? Amperes (Coulombs per Second) 3) What is electrical resistance? Resistance to Electric Current 4) What
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 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 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 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 informationElectricity. Lily, Laura, Lynette, Elyse, Gillian, Emma, Hailey Period 2. onedio.com
Electricity Lily, Laura, Lynette, Elyse, Gillian, Emma, Hailey Period 2 onedio.com Electrostatics vs. Electricity Electrostatics is the study of charges at rest Electrostatics: to help remember the difference
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 informationChapter 28 Solutions
Chapter 8 Solutions 8.1 (a) P ( V) R becomes 0.0 W (11.6 V) R so R 6.73 Ω (b) V IR so 11.6 V I (6.73 Ω) and I 1.7 A ε IR + Ir so 15.0 V 11.6 V + (1.7 A)r r 1.97 Ω Figure for Goal Solution Goal Solution
More informationPhysics 102: Lecture 05 Circuits and Ohm s Law
Physics 102: Lecture 05 Circuits and Ohm s Law Physics 102: Lecture 5, Slide 1 Summary of Last Time Capacitors Physical C = ke 0 A/d C=Q/V Series 1/C eq = 1/C 1 + 1/C 2 Parallel C eq = C 1 + C 2 Energy
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 informationEXPERIMENT 5A RC Circuits
EXPERIMENT 5A Circuits Objectives 1) Observe and qualitatively describe the charging and discharging (decay) of the voltage on a capacitor. 2) Graphically determine the time constant for the decay, τ =.
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 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 informationConcepTest PowerPoints
ConcepTest PowerPoints Chapter 19 Physics: Principles with Applications, 6 th edition Giancoli 2005 Pearson Prentice Hall This work is protected by United States copyright laws and is provided solely for
More informationChapter 21. Ac Circuits
Chapter 21 Ac Circuits AC current Transformer Transforms AC voltage UP or DOWN Historical basis for AC Grid your use George Westinghouse (AC) vs Edison (DC) Losses due to resistance in wire and eddy currents
More informationΔV of battery. = ε  Ir or εmf = I(R+r) (for this particular series circuit) March 04, Emf and internal resistance. Emf and internal resistance
Emf and internal resistance Emf and internal resistance ΔV of battery = ε  Ir or εmf = I(R+r) (for this particular series circuit) As the current in the circuit increases the voltage, supplied to the
More informationDC Circuits. Electromotive Force Resistor Circuits. Kirchoff s Rules. RC Circuits. Connections in parallel and series. Complex circuits made easy
DC Circuits Electromotive Force esistor Circuits Connections in parallel and series Kirchoff s ules Complex circuits made easy C Circuits Charging and discharging Electromotive Force (EMF) EMF, E, is the
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 informationReview. Multiple Choice Identify the letter of the choice that best completes the statement or answers the question.
Review Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. 1. When more devices are added to a series circuit, the total circuit resistance: a.
More informationCopyright 2008 Pearson Education, Inc., publishing as Pearson AddisonWesley.
Surprising as it may seem, the power of a computer is achieved simply by the controlled flow of charges through tiny wires and circuit elements. Chapter Goal: To understand the fundamental physical principles
More informationElectric Current Unlike static electricity, electric current is a continuous flow of charged particles (electricity). For current to flow, there must
CURRENT ELECTRICITY Electric Current Unlike static electricity, electric current is a continuous flow of charged particles (electricity). For current to flow, there must be a power source and there must
More informationPHYS 1102 EXAM  II. SECTION: (Circle one) 001 (TH 9:30 AM to 10:45AM) 002 (TH 3:30 PM to 4:45 PM) You have 1 hr 45 minutes to complete the test
PHYS 1102 EXAM  II SECTION: (Circle one) 001 (TH 9:30 AM to 10:45AM) 002 (TH 3:30 PM to 4:45 PM) Your Name: Student ID: You have 1 hr 45 minutes to complete the test PLEASE DO NOT START TILL YOU ARE INSTRUCTED
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 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 informationDirectCurrent Circuits
DirectCurrent Circuits A'.3/.". 39 ' )232./ 32,+/" 7+3(5.)232./ 7 3244)'03,.5B )*+," &'&./( 01*234 352567+ *7 2829*4& )"< 35 )*+,"= 94 3563 A0.5.C2/'231).D')232.')21 < /633">&@5:836+0"1464625"4*43"
More informationLecture 1. Electrical Transport
Lecture 1. Electrical Transport 1.1 Introduction * Objectives * Requirements & Grading Policy * Other information 1.2 Basic Circuit Concepts * Electrical l quantities current, voltage & power, sign conventions
More information52 VOLTAGE, CURRENT, RESISTANCE, AND POWER
52 VOLTAGE, CURRENT, RESISTANCE, AND POWER 1. What is voltage, and what are its units? 2. What are some other possible terms for voltage? 3. Batteries create a potential difference. The potential/voltage
More informationTo receive full credit, you must show all your work (including steps taken, calculations, and formulas used).
Page 1 Score Problem 1: (35 pts) Problem 2: (25 pts) Problem 3: (25 pts) Problem 4: (25 pts) Problem 5: (15 pts) TOTAL: (125 pts) To receive full credit, you must show all your work (including steps taken,
More informationCircuits. 1. The Schematic
+ ircuits 1. The Schematic 2. Power in circuits 3. The Battery 1. eal Battery vs. Ideal Battery 4. Basic ircuit nalysis 1. oltage Drop 2. Kirchoff s Junction Law 3. Series & Parallel 5. Measurement Tools
More informationNotes: Ohm s Law and Electric Power
Name: Date: / / 644 Intro Physics Notes: Ohm s Law and Electric Power Ohm s Law: Important Terms Term Symbol Units Definition 1. current I amps flow of electric charges through a conductor 2. voltage V
More informationElectricity & Optics
Physics 241 Electricity & Optics Lecture 12 Chapter 25 sec. 6, 26 sec. 1 Fall 217 Semester Professor Koltick Circuits With Capacitors C Q = C V V = Q C + V R C, Q Kirchhoff s Loop Rule: V I R V = V I R
More informationDirect 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
More informationCircuits. PHY2054: Chapter 18 1
Circuits PHY2054: Chapter 18 1 What You Already Know Microscopic nature of current Drift speed and current Ohm s law Resistivity Calculating resistance from resistivity Power in electric circuits PHY2054:
More informationPHYSICS 171. Experiment 3. Kirchhoff's Laws. Three resistors (Nominally: 1 Kilohm, 2 Kilohm, 3 Kilohm).
PHYSICS 171 Experiment 3 Kirchhoff's Laws Equipment: Supplies: Digital Multimeter, Power Supply (020 V.). Three resistors (Nominally: 1 Kilohm, 2 Kilohm, 3 Kilohm). A. Kirchhoff's Loop Law Suppose that
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. 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 informationCurrent. 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
More informationCHARGES IN AN ELECTRIC FIELD
CONTENT POTENTIAL ENERGY AND WORK HSC Physics Module 4 Electricity and Magnetism Electric Field Potential energy, Work and Equipotential Lines CHARGES IN AN ELECTRIC FIELD A charge in an electric field
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 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 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 informationPhysics 201. Professor P. Q. Hung. 311B, Physics Building. Physics 201 p. 1/3
Physics 201 p. 1/3 Physics 201 Professor P. Q. Hung 311B, Physics Building Physics 201 p. 2/3 Summary of last lecture Equipotential surfaces: Surfaces where the potential is the same everywhere, e.g. the
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 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 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 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 informationThe next two questions pertain to the situation described below. Consider a parallel plate capacitor with separation d:
PHYS 102 Exams Exam 2 PRINT (A) The next two questions pertain to the situation described below. Consider a parallel plate capacitor with separation d: It is connected to a battery with constant emf V.
More informationExperiment 4. RC Circuits. Observe and qualitatively describe the charging and discharging (decay) of the voltage on a capacitor.
Experiment 4 RC Circuits 4.1 Objectives Observe and qualitatively describe the charging and discharging (decay) of the voltage on a capacitor. Graphically determine the time constant τ for the decay. 4.2
More informationMaterial World: Electricity
17. Coulomb s Law The force, F, between two objects with charge q1 and q2, is given by: k q q 1 2 F , where r = distance between the two charges in meters 2 r k = Coulomb's constant = 9 X 10 9 m 2 /C
More informationElectricity Test Review
Electricity Test Review Definitions; Series Circuit, Parallel Circuit, Equivalent Resistance, Fuse, Circuit Breaker, kilowatt hour, load, short circuit, dry cell, wet cell, fuel cells, solar cells, fossil
More informationChapter 28 Direct Current Circuits
Chapter 28 Direct Current Circuits Multiple Choice 1. t what rate is thermal energy being generated in the 2resistor when = 12 V and = 3.0 Ω? 2 a. 12 W b. 24 W c. 6.0 W d. 3.0 W e. 1.5 W 2. t what rate
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 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 informationAs light level increases, resistance decreases. As temperature increases, resistance decreases. Voltage across capacitor increases with time LDR
LDR As light level increases, resistance decreases thermistor As temperature increases, resistance decreases capacitor Voltage across capacitor increases with time Potential divider basics: R 1 1. Both
More informationThe RC Time Constant
The RC Time Constant Objectives When a directcurrent source of emf is suddenly placed in series with a capacitor and a resistor, there is current in the circuit for whatever time it takes to fully charge
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 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 informationDC CIRCUIT ANALYSIS. Loop Equations
All of the rules governing DC circuits that have been discussed so far can now be applied to analyze complex DC circuits. To apply these rules effectively, loop equations, node equations, and equivalent
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 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 informationPhysics Circuits: Series
FACULTY OF EDUCATION Department of Curriculum and Pedagogy Physics Circuits: Series Science and Mathematics Education Research Group Supported by UBC Teaching and Learning Enhancement Fund 20122013 Series
More informationELECTRIC CURRENT IN CONDUCTORS CHAPTER  32
1. Q(t) t + Bt + c a) t Q Q 'T ' T t T b) Bt Q B Q 'T' t T c) C [Q] C T ELECTRIC CURRENT IN CONDUCTORS CHPTER  3 1 1 d) Current t dq d t Bt C dt dt t + B 5 5 + 3 53.. No. of electrons per second 16 electrons
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 informationPhys 2025, First Test. September 20, minutes Name:
Phys 05, First Test. September 0, 011 50 minutes Name: Show all work for maximum credit. Each problem is worth 10 points. Work 10 of the 11 problems. k = 9.0 x 10 9 N m / C ε 0 = 8.85 x 101 C / N m e
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 information(b) State the relation between work, charge and potential difference for an electric circuit.
Question Bank on ChElectricity 1. (a) Define the S.I unit of potential difference. (b) State the relation between work, charge and potential difference for an electric circuit. Calculate the potential
More informationin series Devices connected in series will have the same amount of charge deposited on each capacitor. But different potential difference. That means
Electric Field Electricity Lecture Series Electric Field: Field an area where any charged object will experience an electric force Kirchoff s Laws The electric field lines around a pair of point charges
More informationApplication of Physics II for. Final Exam
Application of Physics II for Final Exam Question 1 Four resistors are connected as shown in Figure. (A)Find the equivalent resistance between points a and c. (B)What is the current in each resistor if
More informationRelating Voltage, Current and Resistance
Relating Voltage, Current and Resistance Using Ohm s Law in a simple circuit. A Simple Circuit Consists of:! A voltage source often a battery! A load such as a bulb! Conductors arranged to complete a circuit
More information