# Ch 28-DC 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.

Size: px
Start display at page:

Download "Ch 28-DC 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."

Transcription

1 Ch 28-DC 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.)

2 Resistors in series! One of the bits of nastiness about DC circuits is that they can be disguised to look like something they are not. Look at the circuit on the left. Its general form looks like a parallel combination. Think about the characteristics of a parallel combination, though, (each element connected to its neighbor on either side of the element) and you see it clearly isn t (in fact, each element is connected to each neighbor at only one place, and there are no nodes junctions between any of the elements these are the signs of a series combination which is is). The moral of the story is this: if a circuit looks complicated, you many be able to redraw it (see circuit to right) in a way that makes it not so obscure. 3.) Resistors in series! What is the current flow in this circuit?! What is the voltage drop across each resistor?! 10! 30! 60! (Look at series movie in Richard s stuff ) 100 volts 4.)

3 Resistors in series! What is the current flow in this model?! The equivalent resistance of a group of resistors is the single resistor that will do the same thing in the circuit as does the combination. In the case of a series combination of resistors, it s the single resistor that, when put across the circuit s battery, will draw the same current as the combination. We know that: R equivalent = R 1 + R 2 + R (for resistors in series) so we can write: 10! 30! 60! 100 volts 5.) Resistors in series! What is the current flow in this model?! The equivalent resistance of a group of resistors is the single resistor that will do the same thing in the circuit as does the combination. In the case of a series combination of resistors, it s the single resistor that, when put across the circuit s battery, will draw the same current as the combination. We know that: R equivalent = R 1 + R 2 + R (for resistors in series) so we can write: 10! 30! 60! 100 volts What is the voltage drop across each resistor?! 6.)

4 Resistors in parallel! 7.) Resistors in parallel! What is the voltage drop over each resistor in this model?! What is the current through each resistor?! 10! 8! (Look at parallel movie in Richard s stuff ) 6! 24 volts 1 R equivalent = 1 R R R (for resistors in parallel) 8.)

5 Example 1! Examine the circuit here.! 3! 6! 9! 18V a. What is the equivalent resistance?" R equiv =3! +6! +9! =18!! b. Find the current flowing throughout the circuit." I=V/R=18V/18! =1.0A! c. What is the potential at every point in the circuit." V 3 =IR=(1A)(3!)=3V; V 6 =6V; V 9 =9V! d. What is the Power delivered by the battery?" P=IV=(1.0A)(18V)=18W! e. What is the Power consumed by each resistor?" P 3 =IV=(1.0A)(3V)=3W; or use P 3 =I 2 R=(1A)(3!)=3W; or use P 3 =V 2 /R=(3V) 2 /3A=3W; P 6 =6W; P 9 =9W! 9.) Example 2! Examine the circuit here.! 24V 6! 4! 12! a. What is the equivalent resistance?" 1/R equiv =1/4! +1/6! +1/12!; R equiv =2!! b. Find the current flowing throughout the circuit." V drop identical for each resistor=24v! c. What is the potential at every point in the circuit." I from battery = V/R equiv = 24V/2! =12A; I 4 =V/R= (24V)/(4!)=6A; I 6 =4A; I 12 =2A! d. What is the Power delivered by the battery?" Total power P = (I) V = (12 amps)(24 volts) = 288 watts.! e. What is the Power consumed by each resistor?" P = (I)^2 R yields power values of 48 watts for the 12 ohm resistor, 96 watts for the 6 ohm resistor and 144 watts for the 6 ohm resistor for a total of (tada) 288 watts.! 10.)

6 Example 3! Examine the circuit here.! 6! 12! 36V 8! a. What is the equivalent resistance?" b. Find the current flowing throughout the circuit." c. What is the potential at every point in the circuit." d. What is the Power delivered by the battery?" e. What is the Power consumed by each resistor?" 11.) Kirchhoff s Rules! 12.)

7 Kirchhoff s Rule 1! The Junction Rule - Total current into a node = total current out of a node! I 2 I 1 I 2 I 1 I 3 I 3 I 2 I 1 I 3 13.) Kirchhoff s Rule 2! The Loop Rule - The sum of the potential changes around a closed loop must equal zero.! 14.)

8 Using Kirchhoff s! 1. On circuit diagram, identify and label a current and direction of flow for each separate branch of the circuit.! 2. Write out a series of Node equations using Kirchhoff s Junction Rule.(Make sure you don t duplicate any equations!)! 3. Write out a series of Loop equations using Kirchhoff s Loop Rule. (The total number of Junction and Loop equations = the number of unknown currents you re solving for.)! 4. Solve these simultaneous equations.! 15.) Example 4! Examine the circuit here.! 2 Ω a. What is the current flow, everywhere?" b. What are the voltages, everywhere?" 8 Ω 5 V 5 Ω c. What is the Power consumed/ produced, everywhere?" 15 Ω 10 V 16.)

9 Example 4! Examine the circuit here.! Apply Kirchoff s rules to circuit with currents (arbitrarily chosen here) to get:" 2 Ω I 1 5 V I 1 + I 3 = I 2 10!15I 3! 8I 2! 5! 5I 3 = I 2 + 2I 1 = 0 8 Ω I 2 5 Ω 15 Ω I 3 10 V 17.) Example 4! I 1! I 2 + I 3 = 0 0I 1! 8I 2! 20I 3 =!5 2I 1 + 8I 2 + 0I 3 =!5 1! ! 8! 20! ! 5 a. Math -> Matrix -> Edit -> A (for name of matrix)" b. 3 [Enter] 4 [Enter]" c. Enter coefficients and values into Matrix" d. Do rref A (reduced row echelon form)" e. Interpret answers from matrix" " 1!1 1 0% \$ ' \$ 0! 8! 20! 5 ' # \$ 2 8 0! 5& ' " 1 0 0! % \$ ' \$ 0 1 0! ' # \$ &' 18.)

10 Six Flags/Magic Mountain! When: Monday, April 5, 2010! Who: All able-bodied senior physics students! How much: Don't worry about it. (Book bill)! Leaving: In AM. Come to school and meet in 203.! Returning: That depends. Let's talk about it.! Assignment: One "applied physics" problem, assigned at beginning of April! Write-up: A "nice" one, word processed, 3-7 pages, with diagrams, illustrations, data tables, graphs, calculations, blurbs, explanations, sources of error, as required.! 19.) Six Flags/Magic Mountain! 20.)

11 Six Flags/Magic Mountain! 21.) Six Flags/Magic Mountain! 22.)

12 Series & Parallel Activity! Examine the series and parallel circuits assembled in class... and don t touch the wires.! 23.) RC Circuits - Charge! V o!v capacitor!v resistor = 0 V o! q plate C! I instr = 0 V o! q plate C! dq dt R = 0 dq dt = V o R! q RC dq dt = V o R! q RC dq dt = " V oc RC! q % \$ ' = V oc! q # RC& RC dq q!v o C =!1 RC dt q dq ( = q!v o C 0 t ( 0!1 RC dt q!t ln( q!v o C) 0 = RC ln( q!v oc!v o C ) =!t RC q(t) = CV o [1! e!t / RC ] q(t) = Q[1! e!t / RC ] 24.)

13 RC Circuits - Charging! The quantity! = RC is called the time constant for the circuit, and (in this circuit) represents the amount of time (in seconds) for the charge to reach of its total value." q(t) = Q(1! e!t / RC ) 25.) RC Circuits - Discharging! What is the function for a discharging capacitor? What does! = RC represent for a discharging capacitor?" Q o q(t) = Q(e!t / RC ) t 26.)

14 RC Circuits - Current! q(t) = Q[1! e!t / RC ] I = dq dt I = d dt (Q[1! e!t / RC ]) I = Q( d dt 1! e!t / RC ) I = Q(!1 RC )(!e!t / RC ) I(t) = V o R e!t / RC!t / RC I(t) = I o e 27.) RC Circuits - Current! What is the function for current of a discharging capacitor?" I(t) =! Q RC e!t / RC 28.)

15 Example 5! An RC circuit has a 6V battery, a 200µF capacitor, and a 5000! resistor." a. Draw a picture of the circuit.! b. What is the flow of current through the circuit I o just after the switch is thrown?! c. What is the time constant for the circuit?! d. How much current is flowing in the circuit 5 seconds after the switch has been thrown?! e. Sketch a graph of the circuit s current vs. time, using at least 3 data points that you calculate." 29.) Galvanometers! A galvanometer is an ammeter that is designed to swing fulldeflection when.5 ma (.0005 amps) of current flows through it. If one is clever, a galvanometer can be used to build a voltmeter or larger current ammeter. We are about to be clever.! COM V! COM V! Ideal voltmeters have high resistance." Ideal ammeters have low resistance." 30.)

16 Ammeter:! Example: Create a 2 amp ammeter starting with the frame provided above (i.e., I ve provided the galvanometer you put in the circuit and determine any extraneous resistances). You may assume the galvanometer s resistance is 12 ohms. 31.) Example: Create a 2 amp ammeter. For the galvanometer to go full deflection--something you want it to do when 2 amps flow into it--you need to shunt some of the current away from the galvanometer. The current that does not flow into the galvanometer flows through the shunt resistor. In this case, that will be = amps. The two resistances are in parallel, so the voltage across each will be the same. As such, we can write: 2 A i g R g = i s R s R g =12! R s =?! 5x10 "4 A i s = A ( ) 12 #! R \$ 3x10 "3 # i g =5x10-4 A ( ) = ( R) Note: A short wire across the galvanometer s terminals will give us this resistance. Also, the equivalent resistance of a parallel combination of resistors is smaller than the smallest resistor in the combination. That means the equivalent resistance of this ammeter is less than three thousandths of an ohm. That is exactly what we expected. Ammeters have little net resistance to charge flow (hence current is not impacted by putting one directly into a circuit). 32.)

17 Voltmeter:! Example: Create a 2 volt voltmeter starting with the frame provided above (i.e., put in the circuit and determine any extraneous resistances). You may assume the galvanometer s resistance is 12 ohms. 33.) For the galvanometer to go full deflection--something you want it to do when 2 amps flow into it--you to have a half milliamp flow through it. Two volts across a 12 ohm galvanometer will produce a huge current, so you have to cut the current down some. You do that by putting a resistor in series with the galvanometer. Remembering that the current through resistors in series is the same, we can write: V = i g R g + i g R R g =12! R i g =5x10-4 A 2 volts ( ) 12 #! 2= 5x10 "4 A! R \$ 4x10 3 # ( ) R ( ) + 5x10 "4 A ( ) Note: The equivalent resistance of a series combination of resistors is larger than the largest resistor in the combination. That means the equivalent resistance of this voltmeter is greater than four thousand ohm. That is exactly what we expected. Voltmeters have huge resistance to charge flow (hence little current passes through them when put in a circuit). 34.)

18 Mr. White s Ammeters! The galvanometer all by itself has some resistance (say 100 Ω), and deflects fully across the face of the meter at some current value (say A). How can we alter this galvanometer so that it will be able to measure currents (deflect fully) up to 0.100A?! COM V! V full deflection = IR = (0.0005A)(100!) = 0.050V R needed = V I new = 0.05V 0.10A = 0.5! = 1 R shunt 0.5 R shunt =.503! 35.) Mr. White s Voltmeters! COM V! The galvanometer all by itself has some resistance (say 100 Ω), and deflects fully across the face of the meter at some potential value (say 0.05 V). How can we alter this galvanometer so that it will be able to measure currents (deflect fully) up to 10 V?! V = IR = ( A)(100!) = V R needed = V new 10V = I A = 20,000! R = 20,000! R = 19,900! 36.)

### Direct 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

### Physics 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

### Chapter 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

### Chapter 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 [1-e -t/(rc) ] q = q 0 e -t/(rc τ = RC

### Capacitance, 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

### Chapter 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

### Chapter 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

### Capacitance. 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

Superconductors 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

### 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

### Chapter 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

### Electricity & Magnetism

Electricity & Magnetism D.C. Circuits Marline Kurishingal Note : This chapter includes only D.C. In AS syllabus A.C is not included. Recap... Electrical Circuit Symbols : Draw and interpret circuit diagrams

### 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

### AP 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 cross-sectional area of the conductor changes. If a conductor has no current,

### Electromotive 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,

### Chapter 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

### Chapter 7 Direct-Current Circuits

Chapter 7 Direct-Current Circuits 7. Introduction... 7. Electromotive Force... 7.3 Resistors in Series and in Parallel... 4 7.4 Kirchhoff s Circuit Rules... 6 7.5 Voltage-Current Measurements... 8 7.6

### Lab 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:

### Chapter 26 Direct-Current Circuits

Chapter 26 Direct-Current 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

### DC 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

### Note-A-Rific: Kirchhoff s

Note-A-Rific: Kirchhoff s We sometimes encounter a circuit that is too complicated for simple analysis. Maybe there is a mix of series and parallel, or more than one power source. To deal with such complicated

### Kirchhoff s Rules. Kirchhoff s rules are statements used to solve for currents and voltages in complicated circuits. The rules are

Kirchhoff s Rules Kirchhoff s rules are statements used to solve for currents and voltages in complicated circuits. The rules are Rule. Sum of currents into any junction is zero. i = 0 i 1 2 = 12 Why?

### CHAPTER D.C. CIRCUITS

Solutions--Ch. 16 (D.C. Circuits) CHAPTER 16 -- D.C. CIRCUITS 16.1) Consider the circuit to the right: a.) The voltage drop across R must be zero if there is to be no current through it, which means the

### Review of Ohm's Law: The potential drop across a resistor is given by Ohm's Law: V= IR where I is the current and R is the resistance.

DC Circuits Objectives The objectives of this lab are: 1) to construct an Ohmmeter (a device that measures resistance) using our knowledge of Ohm's Law. 2) to determine an unknown resistance using our

### Direct-Current Circuits

Direct-Current Circuits A'.3/.". 39 '- )232.-/ 32,+/" 7+3(5-.)232.-/ 7 3244)'03,.5B )*+,"- &'&./( 0-1*234 35-2567+- *7 2829*4-& )"< 35- )*+,"-= 9-4-- 3563 A0.5.C2/'-231).D')232.')2-1 < /633-">&@5-:836+-0"1464-625"-4*43"

### Phys 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 10-1 C / N m e

### Chapter 26 Direct-Current and Circuits. - Resistors in Series and Parallel - Kirchhoff s Rules - Electric Measuring Instruments - R-C Circuits

Chapter 26 Direct-Current and Circuits - esistors in Series and Parallel - Kirchhoff s ules - Electric Measuring Instruments - -C Circuits . esistors in Series and Parallel esistors in Series: V ax I V

### 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

### Chapter 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

### Chapter 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,

### Physics 7B-1 (A/B) Professor Cebra. Winter 2010 Lecture 2. Simple Circuits. Slide 1 of 20

Physics 7B-1 (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

### Chapter 26 Direct-Current Circuits

Chapter 26 Direct-Current 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

### ELECTRIC 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

### Chapter 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

### Multi-loop Circuits and Kirchoff's Rules

1 of 8 01/21/2013 12:50 PM Multi-loop Circuits and Kirchoff's Rules 7-13-99 Before talking about what a multi-loop circuit is, it is helpful to define two terms, junction and branch. A junction is a point

### Circuits. 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:

### AP Physics C - E & M

AP Physics C - E & M Current and Circuits 2017-07-12 www.njctl.org Electric Current Resistance and Resistivity Electromotive Force (EMF) Energy and Power Resistors in Series and in Parallel Kirchoff's

### physics for you February 11 Page 68

urrent Electricity Passage 1 4. f the resistance of a 1 m length of a given wire t is observed that good conductors of heat are also is 8.13 10 3 W, and it carried a current 1, the good conductors of electricity.

### 52 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

### 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

### Chapter 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

### Circuits Practice Websheet 18.1

Circuits Practice Websheet 18.1 Multiple Choice Identify the choice that best completes the statement or answers the question. 1. How much power is being dissipated by one of the 10-Ω resistors? a. 24

### Clicker 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

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

### 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

### Physics 212. Lecture 11. RC Circuits. Change in schedule Exam 2 will be on Thursday, July 12 from 8 9:30 AM. Physics 212 Lecture 11, Slide 1

Physics 212 Lecture 11 ircuits hange in schedule Exam 2 will be on Thursday, July 12 from 8 9:30 AM. Physics 212 Lecture 11, Slide 1 ircuit harging apacitor uncharged, switch is moved to position a Kirchoff

### Electric Currents. Resistors (Chapters 27-28)

Electric Currents. Resistors (Chapters 27-28) Electric current I Resistance R and resistors Relation between current and resistance: Ohm s Law Resistivity ρ Energy dissipated by current. Electric power

### 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 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

### Resistivity and Temperature Coefficients (at 20 C)

Homework # 4 Resistivity and Temperature Coefficients (at 0 C) Substance Resistivity, Temperature ( m) Coefficient, (C ) - Conductors Silver.59 x 0-0.006 Copper.6 x 0-0.006 Aluminum.65 x 0-0.0049 Tungsten

### Power lines. Why do birds sitting on a high-voltage 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

### PHYSICS 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 (0-20 V.). Three resistors (Nominally: 1 Kilohm, 2 Kilohm, 3 Kilohm). A. Kirchhoff's Loop Law Suppose that

### AC 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

### ConcepTest 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

### PEP 2017 Assignment 12

of the filament?.16.. Aductile metal wire has resistance. What will be the resistance of this wire in terms of if it is stretched to three times its original length, assuming that the density and resistivity

### Review. 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.

### Electric 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

### Chapter 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

### Review. Spring Semester /21/14. Physics for Scientists & Engineers 2 1

Review Spring Semester 2014 Physics for Scientists & Engineers 2 1 Notes! Homework set 13 extended to Tuesday, 4/22! Remember to fill out SIRS form: https://sirsonline.msu.edu Physics for Scientists &

### Introductory Circuit Analysis

Introductory Circuit Analysis CHAPTER 6 Parallel dc Circuits OBJECTIVES Become familiar with the characteristics of a parallel network and how to solve for the voltage, current, and power to each element.

### 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

### 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

### Laboratory 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

### Physics 1214 Chapter 19: Current, Resistance, and Direct-Current Circuits

Physics 1214 Chapter 19: Current, Resistance, and Direct-Current Circuits 1 Current current: (also called electric current) is an motion of charge from one region of a conductor to another. Current When

### Electric 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*

### Physics 220: Worksheet 7

(1 A resistor R 1 =10 is connected in series with a resistor R 2 =100. A current I=0.1 A is present through the circuit. What is the power radiated in each resistor and also in the total circuit? (2 A

### 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

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

### POLYTECHNIC UNIVERSITY Electrical Engineering Department. EE SOPHOMORE LABORATORY Experiment 2 DC circuits and network theorems

POLYTECHNIC UNIVERSITY Electrical Engineering Department EE SOPHOMORE LABORATORY Experiment 2 DC circuits and network theorems Modified for Physics 18, Brooklyn College I. Overview of Experiment In this

### 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

### R 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

### The General Resistor Circuit Problem

The General Resistor Circuit Problem We re now ready to attack the general resistor circuit problem that may have many sources of EMF, many resistors, and many loops. Remember, the basic laws that we ll

### LABORATORY 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

### physics 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

### Tactics 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

### PHYS 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

### 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

### Circuits Capacitance of a parallel-plate capacitor : C = κ ε o A / d. (ρ = resistivity, L = length, A = cross-sectional area) Resistance : R = ρ L / A

k = 9.0 x 109 N m2 / C2 e = 1.60 x 10-19 C ε o = 8.85 x 10-12 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

### Discussion Question 7A P212, Week 7 RC Circuits

Discussion Question 7A P1, Week 7 RC Circuits The circuit shown initially has the acitor uncharged, and the switch connected to neither terminal. At time t = 0, the switch is thrown to position a. C a

### Electric 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

### 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

### PH 222-2C Fall Circuits. Lectures Chapter 27 (Halliday/Resnick/Walker, Fundamentals of Physics 8 th edition)

PH 222-2C Fall 2012 Circuits Lectures 11-12 Chapter 27 (Halliday/Resnick/Walker, Fundamentals of Physics 8 th edition) 1 Chapter 27 Circuits In this chapter we will cover the following topics: -Electromotive

### Experiment #6. Thevenin Equivalent Circuits and Power Transfer

Experiment #6 Thevenin Equivalent Circuits and Power Transfer Objective: In this lab you will confirm the equivalence between a complicated resistor circuit and its Thevenin equivalent. You will also learn

### DEPARTMENT OF COMPUTER ENGINEERING UNIVERSITY OF LAHORE

DEPARTMENT OF COMPUTER ENGINEERING UNIVERSITY OF LAHORE NAME. Section 1 2 3 UNIVERSITY OF LAHORE Department of Computer engineering Linear Circuit Analysis Laboratory Manual 2 Compiled by Engr. Ahmad Bilal

### Switch. R 5 V Capacitor. ower upply. Voltmete. Goals. Introduction

Switch Lab 9. Circuits ower upply Goals + + R 5 V Capacitor V To appreciate the capacitor as a charge storage device. To measure the voltage across a capacitor as it discharges through a resistor, and

### 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:

### Physics 6B Summer 2007 Final

Physics 6B Summer 2007 Final Question 1 An electron passes through two rectangular regions that contain uniform magnetic fields, B 1 and B 2. The field B 1 is stronger than the field B 2. Each field fills

### Physics 169. Luis anchordoqui. Kitt Peak National Observatory. Wednesday, March 8, 17

Physics 169 Kitt Peak National Observatory Luis anchordoqui 1 5.1 Ohm s Law and Resistance ELECTRIC CURRENT is defined as flow of electric charge through a cross-sectional area Convention i = dq dt Unit

### 1. How does a light bulb work?

AP Physics 1 Lesson 12.a Electric Current and Circuits Outcomes 1. Determine the resistance of a resistor given length, cross-sectional area and length. 2. Relate the movement of charge to differences

### 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

### 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

Course Updates http://www.phys.hawaii.edu/~varner/phys272-spr10/physics272.html Notes for today: 1) Chapter 26 this week (DC, C circuits) 2) Assignment 6 (Mastering Physics) online and separate, written

### Topic 5.2 Heating Effect of Electric Currents

Topic 5.2 Heating Effect of Electric Currents Kari Eloranta 2017 Jyväskylän Lyseon lukio International Baccalaureate February 14, 2017 Topic 5.2 Heating Effect of Electric Currents In subtopic 5.2 we study

### ANNOUNCEMENT ANNOUNCEMENT

ANNOUNCEMENT Exam : Tuesday September 25, 208, 8 PM - 0 PM Location: Elliott Hall of Music (see seating chart) Covers all readings, lectures, homework from Chapters 2 through 23 Multiple choice (5-8 questions)

### ENGG 225. David Ng. Winter January 9, Circuits, Currents, and Voltages... 5

ENGG 225 David Ng Winter 2017 Contents 1 January 9, 2017 5 1.1 Circuits, Currents, and Voltages.................... 5 2 January 11, 2017 6 2.1 Ideal Basic Circuit Elements....................... 6 3 January

### Circuits. 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

### The principles of conservation of energy and charge apply to electrical circuits. Properties of magnetic fields apply in nature and technology.

UIT E UMMARY KEY COCEPT CHAPTER UMMARY 11 The principles of conservation of energy and charge apply to electrical circuits. Electrical circuits Conventional current and electron flow Current, electrical

### Outline. Week 5: Circuits. Course Notes: 3.5. Goals: Use linear algebra to determine voltage drops and branch currents.

Outline Week 5: Circuits Course Notes: 3.5 Goals: Use linear algebra to determine voltage drops and branch currents. Components in Resistor Networks voltage source current source resistor Components in

### Circuits. 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