Lab 08 Capacitors 2. Figure 2 Series RC circuit with SPDT switch to charge and discharge capacitor.

Save this PDF as:

Size: px
Start display at page:

Download "Lab 08 Capacitors 2. Figure 2 Series RC circuit with SPDT switch to charge and discharge capacitor."

Transcription

1 Lab 08: Capacitors Last edited March 5, 2018 Learning Objectives: 1. Understand the short-term and long-term behavior of circuits containing capacitors. 2. Understand the mathematical relationship between the current in the circuit as a function of time, resistance, capacitance, and potential difference. 3. Understand the voltage drop across a capacitor. 4. Calculate the equivalent capacitance of a network of capacitors. Student Expectations: 1. Participation - Up to 10 points for participation and full involvement are earned during each lab class. 2. Lab Records - Take notes for all activities and record items as indicated in the lab instructions. At the end of each lab session, turn in the original Lab Records and upload digital copies to Bb. This assignment is graded for the required elements (out of 14 points). 3. Outside of Class a. For full Homework credit, complete the Lab 08 Homework on Blackboard within one hour before Lab 09. b. For full Quiz credit, read the Pre-Lab Notes and complete the Pre-Lab Quiz for Lab 09 at least one hour before Lab 09. I. Understanding the Models for the Behavior of a Circuit with a Capacitor The capacitor as a circuit element is introduced in the Lab 08 Pre-Lab Notes. To summarize: A capacitor stores electrical energy. A capacitor is modeled as a pair of parallel plates of conductive material, separated by a nonconducting gap. The current through any capacitor is zero. There are circumstances and time scales where the current in the rest of the circuit is non-zero, even with a capacitor in the circuit branch. The schematic symbol is two equal length parallel lines, perpendicular to the wires. The net charge of a capacitor is always zero. Consider the circuit in Fig. 1. h l 1. At the instant just before the switch is closed, what is the potential difference between the plates which are separated by a distance d? 2. What is the magnitude of the electric field between these capacitor plates at this time? Recall that the strength of the electric field can be expressed as a potential difference divided by a distance. Figure 1 A capacitor C in a circuit with battery B and SPST switch S. Consider the circuit divided in half, with one half containing the positive terminal of the battery and plate h and the other half containing the negative terminal of the battery and plate l. When the switch closes, current flows through each half circuit and opposite charges build up on both plates of the Lab 08 Capacitors 1

2 capacitor. Eventually the potential difference between the plates will be the same as the potential difference of the battery since the potential of plate h is the same as the potential of the positive terminal of the battery and the potential of plate l is that of the negative terminal. If there is a total charge +Q on plate h, there is a total charge Q on plate l. 3. A capacitor in this state is said to be fully charged. Note that this description is really a misnomer because, as noted above, the net charge of the capacitor is zero. Fully charged would be better to describe a single capacitor plate, but this is the terminology that is used for the full capacitor. a. When the capacitor is fully charged, what is the electric field in the part of the circuit between the positive terminal of the battery and plate h? b. What about the electric field between the negative terminal of the battery and plate l? c. Based on your responses, what can you say about the magnitude of current flowing through the circuit? The charge magnitude Q on the plates and the potential difference V between the plates are directly proportional to each other and can be expressed as Q = CV. The constant of proportionality C is called the capacitance of the capacitor. Note that capacitance is the ability of an object to store separated electrical charges and that any object that can be electrically charged exhibits capacitance. Because capacitors are able to store electrical energy, they act like small batteries and can store or release the energy as required. The capacitance depends only on the geometry of the plates and not on charge or potential difference between the plates. The unit of capacitance is the farad (denoted as F), which is defined as 1 F = 1 C/V or 1 coulomb/volt. Although determining the capacitance appears to be a matter of measuring the charge, such devices are expensive. Instead, a circuit modified from that in Fig. 1 is used to measure the capacitance (see Fig. 2). Adding a resistor in series with the capacitor and battery allows investigation of the time behavior of the battery current and voltage across the capacitor. Figure 2 Series RC circuit with SPDT switch to charge and discharge capacitor. The conceptual and mathematical models of voltage, current, and resistance (e.g., V = IR and Kirchoff s Rules) that were developed in earlier labs for a steady current flow hold for flow that is not steady. Using these models, it can be shown that the time dependence of the current flow through the battery or resistor when the switch is first connected to pole a at t = 0 is given by equation (1). The models can also be used to show that during this charging, the capacitor voltage V cap (the potential difference between or across the plates) is given by equation (2). Lab 08 Capacitors 2

3 II(tt) = VV batt RR ee tt/rrrr (1) VV cap (tt) = VV batt 1 ee tt/rrrr (2) 4. Using these equations, what is the magnitude of the current through the battery and the voltage across the capacitor just after the circuit is connected (i.e. t = 0)? 5. Now assume that enough time has passed that the capacitor is fully charged. a. What is the magnitude of the current flow and the potential difference across the capacitor at just before the switch is flipped to position b in Figure 2 (i.e., tt = for Eqs. (1) and (2))? b. How do these values compare to your predictions made earlier in Step 3? c. What is the potential difference across the capacitor a long while later when the switch remains at position b in Figure 2? 6. During the process in step 5c, the capacitor is said to be discharging. The current flowing to the capacitor and the voltage across the capacitor can be expressed as the following functions of time: II(tt) = QQ 0 RRRR ee tt/rrrr (3) VV(tt) = VV 0 ee tt/rrrr (4) where tt is now the time after the switch has been thrown, QQ 0 is the initial charge on the capacitor when it begins to discharge, and VV 0 is the voltage across it. QQ 0 is calculated from QQ 0 = CCVV 0. a. What does the negative sign in front of the term QQ 0 indicate in Eq. 3? RRRR b. What is the magnitude of current flowing in the circuit a long time after the switch was thrown? 7. In the four equations above, the factor RRRR in the denominator of the exponent is called the time constant. This is the time that it takes for a charged capacitor to discharge to 36.8% (= 1/ee) of its charged value or for an uncharged capacitor to reach 63.2% = 1 1/ee of full charge. The time constant is denoted by the symbol τ or Tau, where τ = RC. The units of τ are seconds when RR is in ohms (Ω) and CC is in farads (F). Checkpoint 1! Check your answers with your instructor before proceeding. Be sure that you can explain how equations 1, 2, 3, and 4 describe the charging and discharging of the capacitor in Figure 2. II. Measuring Capacitance in an RC Circuit In this experiment the PASCO interface box output serves as both the battery and switch for the RC circuit. It provides a voltage output in the form of a square wave which is a periodic wave that varies abruptly in amplitude between two fixed values (such as 0 volts and 5 volts), spending equal times at each. In doing so, the square wave simulates continually flipping the switch in Figure 2 between points a and b. Note that this interface box also serves as a voltmeter using a second set of wires in the analog port B (see photo below). Lab 08 Capacitors 3

4 1. Measure and record the resistance (and estimated uncertainty) of the resistor on the breadboard (with nothing connected to it but the Wavetek multimeter; manufacturer s specified accuracy is 2% of reading.) 2. Construct an RC circuit similar to Figure 2. The ScienceWorkshop interface takes the place of the elements in the dashed gray box and also measures VV cap. 3. Figure 3 shows an example of the change of VV cap with time in units of RRRR (i.e. the time constant). Sketch this graph in your Lab Records and identify and describe what is happening in the circuit for tt < 7RRRR and for tt > 7RRRR. Figure 3 Example of voltage reading across a capacitor Checkpoint 2! Have your RC circuit checked before continuing. Be sure you can explain Figure On the lab computer desktop, click on Data Studio Experiments> Capacitors to open the DataStudio program for this experiment. To take the data, follow the instructions on the splash page only so far as, Press Start to begin Data Acquisition. a. Sketch and label the resulting graph in your Lab Records. b. Compare your sketch with Figure 3. How does it differ? Why might that be the case? 5. Use the DataStudio curve fitting tool to determine the time constant for the circuit. Hint: Remember that the time constant term shows up in the exponential part of all equations related to the charging and discharging of the capacitor; since the charge is proportional to the voltage and voltage is what Lab 08 Capacitors 4

5 is measured, consider equation 4. Use the selection tool to include data points from the decay portion of the curve. Confusion alert! The constant that DataStudio gives you that you need to use to find the capacitance is C. This constant is NOT the capacitance. 6. Use the values of the time constant and resistance to determine the capacitance CC time constant. 7. Disconnect everything on the breadboard. Use the digital capacitance meter (on the 2000 μf scale) to find the capacitance of the capacitor CC meter that was in the circuit and compare this value to that obtained in step 5. Assume that the only uncertainty comes in the capacitance meter reading. Recall from Physics 1 that the criterion for equivalence (two uncertain numbers represent the same quantity) in this case would be CC time constant CC meter 2uu(CC meter ). The manufacturer s stated precision for the capacitance meter is 5% E.g., if the reading is C = 100 µf, the uncertainty is u(c)=(5%)(100 µf) + 10 µf = 15 µf. Checkpoint 3! Check your findings with your instructor. Lab 08 Capacitors 5

6 III. Determining equivalent capacitance Earlier you worked with two equations that separately calculate the equivalent resistance of a circuit involving resistors in series and resistors in parallel. This section will help you determine the two equations for the equivalent capacitance for capacitors connected in series and capacitors connected in parallel. 1. Measure and record the capacitance of the second capacitor with the Protek meter. 2. Design an experiment to address the research question, How is the equivalent capacitance of two capacitors connected in parallel affected by one of the capacitors? 3. Connect the two capacitors in parallel. Connect the meter as if you were measuring the voltage drop across the combination. Record the measured equivalent capacitance of the pair of capacitors. 4. Using the values of the individual capacitors, how would you combine them to come up with a mathematical rule for the equivalent capacitance of two capacitors in parallel? 5. Design an experiment to address the research question, How is the equivalent capacitance of two capacitors connected in series affected by one of the capacitors? 6. Connect the two capacitors in series. Measure the equivalent capacitance of the pair of capacitors. 7. What is the mathematical rule for the equivalent capacitance of two capacitors in series? Hint: this form is not as obvious, but there are similarities between the equations for equivalent capacitance in series/parallel and resistors in series/parallel. Checkpoint 4! Check the relationships you determined for equivalent capacitance with your instructor. Lab 08 Capacitors 6

Figure 1: Capacitor circuit

Figure 1: Capacitor circuit Capacitors INTRODUCTION The basic function of a capacitor 1 is to store charge and thereby electrical energy. This energy can be retrieved at a later time for a variety of uses. Often, multiple capacitors

More information

Pre-Lab Quiz / PHYS 224. R-C Circuits. Your Name Lab Section

Pre-Lab Quiz / PHYS 224. R-C Circuits. Your Name Lab Section Pre-Lab Quiz / PHYS 224 R-C Circuits Your Name Lab Section 1. What do we investigate in this lab? 2. For the R-C circuit shown in Figure 1 on Page 3, RR = 100 ΩΩ and CC = 1.00 FF. What is the time constant

More information

Lab 10: DC RC circuits

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:

More information

EXPERIMENT 5A RC Circuits

EXPERIMENT 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 information

Experiment 4. RC Circuits. Observe and qualitatively describe the charging and discharging (decay) of the voltage on a capacitor.

Experiment 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 information

[1] (b) Fig. 1.1 shows a circuit consisting of a resistor and a capacitor of capacitance 4.5 μf. Fig. 1.1

[1] (b) Fig. 1.1 shows a circuit consisting of a resistor and a capacitor of capacitance 4.5 μf. Fig. 1.1 1 (a) Define capacitance..... [1] (b) Fig. 1.1 shows a circuit consisting of a resistor and a capacitor of capacitance 4.5 μf. S 1 S 2 6.3 V 4.5 μf Fig. 1.1 Switch S 1 is closed and switch S 2 is left

More information

AP Physics C. Electric Circuits III.C

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,

More information

Name Class Date. RC Circuit Lab

Name Class Date. RC Circuit Lab RC Circuit Lab Objectives: Students will be able to Use the ScienceWorkshop interface to investigate the relationship between the voltage remaining across a capacitor and the time taken for the discharge

More information

Laboratory 7: Charging and Discharging a Capacitor Prelab

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

More information

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

Switch. R 5 V Capacitor. ower upply. Voltmete. Goals. Introduction Switch Lab 6. 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

More information

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

Switch. R 5 V Capacitor. ower upply. Voltmete. Goals. Introduction Switch Lab 6. 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

More information

Lab 4 RC Circuits. Name. Partner s Name. I. Introduction/Theory

Lab 4 RC Circuits. Name. Partner s Name. I. Introduction/Theory Lab 4 RC Circuits Name Partner s Name I. Introduction/Theory Consider a circuit such as that in Figure 1, in which a potential difference is applied to the series combination of a resistor and a capacitor.

More information

Practical 1 RC Circuits

Practical 1 RC Circuits Objectives Practical 1 Circuits 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 information

Name: Lab Partner: Section:

Name: Lab Partner: Section: Chapter 6 Capacitors and RC Circuits Name: Lab Partner: Section: 6.1 Purpose The purpose of this experiment is to investigate the physics of capacitors in circuits. The charging and discharging of a capacitor

More information

first name (print) last name (print) brock id (ab17cd) (lab date)

first name (print) last name (print) brock id (ab17cd) (lab date) (ta initials) first name (print) last name (print) brock id (ab17cd) (lab date) Experiment 1 Capacitance In this Experiment you will learn the relationship between the voltage and charge stored on a capacitor;

More information

On the axes of Fig. 4.1, carefully sketch a graph to show how the potential difference V across the capacitor varies with time t. Label this graph L.

On the axes of Fig. 4.1, carefully sketch a graph to show how the potential difference V across the capacitor varies with time t. Label this graph L. 1 (a) A charged capacitor is connected across the ends of a negative temperature coefficient (NTC) thermistor kept at a fixed temperature. The capacitor discharges through the thermistor. The potential

More information

The RC Time Constant

The RC Time Constant The RC Time Constant Objectives When a direct-current 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 information

Chapter 7 Direct-Current Circuits

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

More information

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

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

More information

Capacitors. Chapter How capacitors work Inside a capacitor

Capacitors. Chapter How capacitors work Inside a capacitor Chapter 6 Capacitors In every device we have studied so far sources, resistors, diodes and transistors the relationship between voltage and current depends only on the present, independent of the past.

More information

Lab 5 CAPACITORS & RC CIRCUITS

Lab 5 CAPACITORS & RC CIRCUITS L051 Name Date Partners Lab 5 CAPACITORS & RC CIRCUITS OBJECTIVES OVERVIEW To define capacitance and to learn to measure it with a digital multimeter. To explore how the capacitance of conducting parallel

More information

Lab 5 - Capacitors and RC Circuits

Lab 5 - Capacitors and RC Circuits Lab 5 Capacitors and RC Circuits L51 Name Date Partners Lab 5 Capacitors and RC Circuits OBJECTIVES To define capacitance and to learn to measure it with a digital multimeter. To explore how the capacitance

More information

Lab 4 CAPACITORS & RC CIRCUITS

Lab 4 CAPACITORS & RC CIRCUITS 67 Name Date Partners Lab 4 CAPACITORS & RC CIRCUITS OBJECTIVES OVERVIEW To define capacitance and to learn to measure it with a digital multimeter. To explore how the capacitance of conducting parallel

More information

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 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 information

Phys 2025, First Test. September 20, minutes Name:

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

More information

Lab 5 - Capacitors and RC Circuits

Lab 5 - Capacitors and RC Circuits Lab 5 Capacitors and RC Circuits L51 Name Date Partners Lab 5 Capacitors and RC Circuits OBJECTIVES To define capacitance and to learn to measure it with a digital multimeter. To explore how the capacitance

More information

ENERGY 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 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 information

Tactics Box 23.1 Using Kirchhoff's Loop Law

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

More information

Chapter 28. Direct Current Circuits

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

More information

2005 AP PHYSICS C: ELECTRICITY AND MAGNETISM FREE-RESPONSE QUESTIONS

2005 AP PHYSICS C: ELECTRICITY AND MAGNETISM FREE-RESPONSE QUESTIONS 2005 AP PHYSICS C: ELECTRICITY AND MAGNETISM In the circuit shown above, resistors 1 and 2 of resistance R 1 and R 2, respectively, and an inductor of inductance L are connected to a battery of emf e and

More information

LAB 3: Capacitors & RC Circuits

LAB 3: Capacitors & RC Circuits LAB 3: Capacitors & C Circuits Name: Circuits Experiment Board Wire leads Capacitors, esistors EQUIPMENT NEEDED: Two D-cell Batteries Multimeter Logger Pro Software, ULI Purpose The purpose of this lab

More information

Old Dominion University Physics 112N/227N/232N Lab Manual, 13 th Edition

Old Dominion University Physics 112N/227N/232N Lab Manual, 13 th Edition RC Circuits Experiment PH06_Todd OBJECTIVE To investigate how the voltage across a capacitor varies as it charges. To find the capacitive time constant. EQUIPMENT NEEDED Computer: Personal Computer with

More information

Capacitors GOAL. EQUIPMENT. CapacitorDecay.cmbl 1. Building a Capacitor

Capacitors GOAL. EQUIPMENT. CapacitorDecay.cmbl 1. Building a Capacitor PHYSICS EXPERIMENTS 133 Capacitor 1 Capacitors GOAL. To measure capacitance with a digital multimeter. To make a simple capacitor. To determine and/or apply the rules for finding the equivalent capacitance

More information

Experiment FT1: Measurement of Dielectric Constant

Experiment FT1: Measurement of Dielectric Constant Experiment FT1: Measurement of Dielectric Constant Name: ID: 1. Objective: (i) To measure the dielectric constant of paper and plastic film. (ii) To examine the energy storage capacity of a practical capacitor.

More information

Laboratory 3 Measuring Capacitor Discharge with the MicroBLIP

Laboratory 3 Measuring Capacitor Discharge with the MicroBLIP Laboratory 3 page 1 of 6 Laboratory 3 Measuring Capacitor Discharge with the MicroBLIP Introduction In this lab, you will use the MicroBLIP in its Data Acquisition Mode to sample the voltage over time

More information

Chapter 8. Capacitors. Charging a capacitor

Chapter 8. Capacitors. Charging a capacitor Chapter 8 Capacitors You can store energy as potential energy by pulling a bowstring, stretching a spring, compressing a gas, or lifting a book. You can also store energy as potential energy in an electric

More information

EXPERIMENT 07 TO STUDY DC RC CIRCUIT AND TRANSIENT PHENOMENA

EXPERIMENT 07 TO STUDY DC RC CIRCUIT AND TRANSIENT PHENOMENA EXPERIMENT 07 TO STUDY DC RC CIRCUIT AND TRANSIENT PHENOMENA DISCUSSION The capacitor is a element which stores electric energy by charging the charge on it. Bear in mind that the charge on a capacitor

More information

EXPERIMENT 12 OHM S LAW

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

More information

MasteringPhysics: Assignment Print View. Problem 30.50

MasteringPhysics: 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 15-cm-long nichrome wire is

More information

P114 University of Rochester NAME S. Manly Spring 2010

P114 University of Rochester NAME S. Manly Spring 2010 Exam 2 (March 23, 2010) Please read the problems carefully and answer them in the space provided. Write on the back of the page, if necessary. Show your work where indicated. Problem 1 ( 8 pts): In each

More information

COPYRIGHTED MATERIAL. DC Review and Pre-Test. Current Flow CHAPTER

COPYRIGHTED MATERIAL. DC Review and Pre-Test. Current Flow CHAPTER Kybett c0.tex V3-03/3/2008 8:44pm Page CHAPTER DC Review and Pre-Test Electronics cannot be studied without first understanding the basics of electricity. This chapter is a review and pre-test on those

More information

IMPORTANT Read these directions carefully:

IMPORTANT Read these directions carefully: Physics 208: Electricity and Magnetism Common Exam 2, October 17 th 2016 Print your name neatly: First name: Last name: Sign your name: Please fill in your Student ID number (UIN): _ - - Your classroom

More information

Lab 6. RC Circuits. Switch R 5 V. ower upply. Voltmete. Capacitor. Goals. Introduction

Lab 6. RC Circuits. Switch R 5 V. ower upply. Voltmete. Capacitor. Goals. Introduction Switch ower upply Lab 6. RC Circuits + + R 5 V Goals 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

More information

Capacitance. A capacitor consists of two conductors that are close but not touching. A capacitor has the ability to store electric charge.

Capacitance. A capacitor consists of two conductors that are close but not touching. A capacitor has the ability to store electric charge. Capacitance A capacitor consists of two conductors that are close but not touching. A capacitor has the ability to store electric charge. a) Parallel-plate capacitor connected to battery. (b) is a circuit

More information

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

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

Switch + R. ower upply. Voltmete. Capacitor. Goals. Introduction

Switch + R. ower upply. Voltmete. Capacitor. Goals. Introduction Lab 6. Switch RC Circuits ower upply Goals To appreciate the capacitor as a charge storage device. To measure the voltage across a capacitor as it discharges through a resistor, and to compare + the result

More information

Laboratory Worksheet Experiment NE04 - RC Circuit Department of Physics The University of Hong Kong. Name: Student ID: Date:

Laboratory Worksheet Experiment NE04 - RC Circuit Department of Physics The University of Hong Kong. Name: Student ID: Date: PHYS1050 / PHYS1250 Laboratory Worksheet Experiment Department of Physics The University of Hong Kong Ref. (Staff Use) Name: Student ID: Date: Draw a schematic diagram of the charging RC circuit with ammeter

More information

farads or 10 µf. The letter indicates the part tolerance (how close should the actual value be to the marking).

farads or 10 µf. The letter indicates the part tolerance (how close should the actual value be to the marking). p1 EE1050/60 Capacitors Lab University of Utah Electrical Engineering Department EE1050/1060 Capacitors A. Stolp, 10/4/99 rev 3/17/01 Objectives 1.) Observe charging and discharging of a capacitor. 2.)

More information

Physics 212 Midterm 2 Form A

Physics 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 10-19 C B. 6.4 10-19 C C. 1 C D. 2 C E. 4 C 2. In a Physics 212 lab, Jane measures the current versus

More information

Experiment P43: RC Circuit (Power Amplifier, Voltage Sensor)

Experiment P43: RC Circuit (Power Amplifier, Voltage Sensor) PASCO scientific Vol. 2 Physics Lab Manual: P43-1 Experiment P43: (Power Amplifier, Voltage Sensor) Concept Time SW Interface Macintosh file Windows file circuits 30 m 700 P43 P43_RCCI.SWS EQUIPMENT NEEDED

More information

RC Circuit Lab - Discovery PSI Physics Capacitors and Resistors

RC Circuit Lab - Discovery PSI Physics Capacitors and Resistors 1 RC Circuit Lab - Discovery PSI Physics Capacitors and Resistors Name Date Period Purpose The purpose of this lab will be to determine how capacitors behave in R-C circuits. The manner in which capacitors

More information

Capacitance. A different kind of capacitor: Work must be done to charge a capacitor. Capacitors in circuits. Capacitor connected to a battery

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

More information

Science Olympiad Circuit Lab

Science 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 information

Experiment 8: Capacitance and the Oscilloscope

Experiment 8: Capacitance and the Oscilloscope Experiment 8: Capacitance and the Oscilloscope Nate Saffold nas2173@columbia.edu Office Hour: Mondays, 5:30PM-6:30PM @ Pupin 1216 INTRO TO EXPERIMENTAL PHYS-LAB 1493/1494/2699 Outline Capacitance: Capacitor

More information

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

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

More information

Prof. Anyes Taffard. Physics 120/220. Voltage Divider Capacitor RC circuits

Prof. Anyes Taffard. Physics 120/220. Voltage Divider Capacitor RC circuits Prof. Anyes Taffard Physics 120/220 Voltage Divider Capacitor RC circuits Voltage Divider The figure is called a voltage divider. It s one of the most useful and important circuit elements we will encounter.

More information

Chapter 2: Capacitors And Dielectrics

Chapter 2: Capacitors And Dielectrics hapter 2: apacitors And Dielectrics 2.1 apacitance and capacitors in series and parallel L.O 2.1.1 Define capacitance and use capacitance apacitor is a device that is capable of storing electric charges

More information

( ) ( ) = q o. T 12 = τ ln 2. RC Circuits. 1 e t τ. q t

( ) ( ) = q o. T 12 = τ ln 2. RC Circuits. 1 e t τ. q t Objectives: To explore the charging and discharging cycles of RC circuits with differing amounts of resistance and/or capacitance.. Reading: Resnick, Halliday & Walker, 8th Ed. Section. 27-9 Apparatus:

More information

July 11, Capacitor CBL 23. Name Date: Partners: CAPACITORS. TI-83 calculator with unit-tounit. Resistor (about 100 kω) Wavetek multimeter

July 11, Capacitor CBL 23. Name Date: Partners: CAPACITORS. TI-83 calculator with unit-tounit. Resistor (about 100 kω) Wavetek multimeter July 11, 2008 - CBL 23 Name Date: Partners: CAPACITORS Materials: CBL unit TI-83 calculator with unit-tounit link cable Resistor (about 100 kω) Connecting wires Wavetek multimeter TI voltage probe Assorted

More information

Lab 5 RC Circuits. What You Need To Know: Physics 212 Lab

Lab 5 RC Circuits. What You Need To Know: Physics 212 Lab Lab 5 R ircuits What You Need To Know: The Physics In the previous two labs you ve dealt strictly with resistors. In today s lab you ll be using a new circuit element called a capacitor. A capacitor consists

More information

PHY222 - Lab 7 RC Circuits: Charge Changing in Time Observing the way capacitors in RC circuits charge and discharge.

PHY222 - Lab 7 RC Circuits: Charge Changing in Time Observing the way capacitors in RC circuits charge and discharge. PHY222 Lab 7 RC Circuits: Charge Changing in Time Observing the way capacitors in RC circuits charge and discharge. Print Your Name Print Your Partners' Names You will return this handout to the instructor

More information

PHYSICS 171 UNIVERSITY PHYSICS LAB II. Experiment 6. Transient Response of An RC Circuit

PHYSICS 171 UNIVERSITY PHYSICS LAB II. Experiment 6. Transient Response of An RC Circuit PHYSICS 171 UNIVERSITY PHYSICS LAB II Experiment 6 Transient Response of An RC Circuit Equipment: Supplies: Function Generator, Dual Trace Oscilloscope.002 Microfarad, 0.1 Microfarad capacitors; 1 Kilohm,

More information

How many electrons are transferred to the negative plate of the capacitor during this charging process? D (Total 1 mark)

How many electrons are transferred to the negative plate of the capacitor during this charging process? D (Total 1 mark) Q1.n uncharged 4.7 nf capacitor is connected to a 1.5 V supply and becomes fully charged. How many electrons are transferred to the negative plate of the capacitor during this charging process? 2.2 10

More information

Chapter 2: Capacitor And Dielectrics

Chapter 2: Capacitor And Dielectrics hapter 2: apacitor And Dielectrics In this chapter, we are going to discuss the different ways that a capacitor could be arranged in a circuit and how its capacitance could be increased. Overview apacitor

More information

Besides resistors, capacitors are one of the most common electronic components that you will encounter. Sometimes capacitors are components that one

Besides resistors, capacitors are one of the most common electronic components that you will encounter. Sometimes capacitors are components that one 1 Besides resistors, capacitors are one of the most common electronic components that you will encounter. Sometimes capacitors are components that one would deliberately add to a circuit. Other times,

More information

Electromotive Force. The electromotive force (emf), ε, of a battery is the maximum possible voltage that the battery can provide between its terminals

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,

More information

Today s agenda: Capacitors and Capacitance. You must be able to apply the equation C=Q/V.

Today s agenda: Capacitors and Capacitance. You must be able to apply the equation C=Q/V. Today s agenda: Capacitors and Capacitance. You must be able to apply the equation C=Q/V. Capacitors: parallel plate, cylindrical, spherical. You must be able to calculate the capacitance of capacitors

More information

Version 001 CIRCUITS holland (1290) 1

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

More information

Physics 220: Worksheet 7

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

More information

7/06 Electric Fields and Energy

7/06 Electric Fields and Energy Part ASome standard electric field and potential configurations About this lab: Electric fields are created by electric charges and exert force on charges. Electric potential gives an alternative description.

More information

DEPARTMENT OF COMPUTER ENGINEERING UNIVERSITY OF LAHORE

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

More information

University of TN Chattanooga Physics 1040L 8/18/2012 PHYSICS 1040L LAB LAB 4: R.C. TIME CONSTANT LAB

University of TN Chattanooga Physics 1040L 8/18/2012 PHYSICS 1040L LAB LAB 4: R.C. TIME CONSTANT LAB PHYSICS 1040L LAB LAB 4: R.C. TIME CONSTANT LAB OBJECT: To study the discharging of a capacitor and determine the time constant for a simple circuit. APPARATUS: Capacitor (about 24 μf), two resistors (about

More information

Capacitors. The charge Q on a capacitor s plate is proportional to the potential difference V across the Q = C V (1)

Capacitors. The charge Q on a capacitor s plate is proportional to the potential difference V across the Q = C V (1) apacitors THEORY The charge Q on a capacitor s plate is proportional to the potential difference V across the capacitor. We express this with Q = V (1) where is a proportionality constant known as the

More information

Capacitance, Resistance, DC Circuits

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

More information

Chapter 26 Direct-Current Circuits

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

More information

The next two questions pertain to the situation described below. Consider a parallel plate capacitor with separation d:

The 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 information

Electronics Capacitors

Electronics Capacitors Electronics Capacitors Wilfrid Laurier University October 9, 2015 Capacitor an electronic device which consists of two conductive plates separated by an insulator Capacitor an electronic device which consists

More information

Dr. Julie J. Nazareth

Dr. Julie J. Nazareth Name: Dr. Julie J. Nazareth Lab Partner(s): Physics: 133L Date lab performed: Section: Capacitors Parts A & B: Measurement of capacitance single, series, and parallel combinations Table 1: Voltage and

More information

Lab 5 RC Circuits. What You Need To Know: Physics 212 Lab

Lab 5 RC Circuits. What You Need To Know: Physics 212 Lab Lab 5 R ircuits What You Need To Know: The Physics In the previous two labs you ve dealt strictly with resistors. In today s lab you ll be using a new circuit element called a capacitor. A capacitor consists

More information

UNIT G485 Module Capacitors PRACTICE QUESTIONS (4)

UNIT G485 Module Capacitors PRACTICE QUESTIONS (4) UNIT G485 Module 2 5.2.1 Capacitors PRACTICE QUESTIONS (4) 1 A 2200 µf capacitor is charged to a p.d. of 9.0 V and then discharged through a 100 kω resistor. (a) Calculate : (i) The initial charge stored

More information

SECTION #1 - The experimental setup

SECTION #1 - The experimental setup Lemon Battery Connected in Series Charging a 2.2 Farad Capacitor SECTION #1 - The experimental setup 1. The goal of this experiment is to see if I can connect 2, 3 or 4 lemons together in a series configuration

More information

Capacitors. Example 1

Capacitors. Example 1 Physics 30AP Resistors and apacitors I apacitors A capacitor is a device for storing electrical charge that consists of two conducting objects placed near one another but not touching. A A typical capacitor

More information

AC vs. DC Circuits. Constant voltage circuits. The voltage from an outlet is alternating voltage

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

More information

Simple circuits - 3 hr

Simple circuits - 3 hr Simple circuits - 3 hr Resistances in circuits Analogy of water flow and electric current An electrical circuit consists of a closed loop with a number of different elements through which electric current

More information

the electrical nature of matter is inherent in its atomic structure E & M atoms are made up of p+, n, and e- the nucleus has p+ and n

the electrical nature of matter is inherent in its atomic structure E & M atoms are made up of p+, n, and e- the nucleus has p+ and n Electric Forces and Fields E & M the electrical nature of matter is inherent in its atomic structure atoms are made up of p+, n, and e- a.k.a Electricity and Magnetism the nucleus has p+ and n surrounding

More information

1. How much charge is stored in a capacitor, whose capacitance C = 2µF, connected to a 12V battery?

1. How much charge is stored in a capacitor, whose capacitance C = 2µF, connected to a 12V battery? IMP 113: 2 nd test (Union College: Spring 2010) Instructions: 1. Read all directions. 2. In keeping with the Union College policy on academic honesty, you should neither accept nor provide unauthorized

More information

Electric Circuits Fall 2015 Solution #5

Electric Circuits Fall 2015 Solution #5 RULES: Please try to work on your own. Discussion is permissible, but identical submissions are unacceptable! Please show all intermeate steps: a correct solution without an explanation will get zero cret.

More information

PHY 101 Practice Exam III Monday, November 27, 2:15-3:35PM

PHY 101 Practice Exam III Monday, November 27, 2:15-3:35PM 1 PHY 101 Practice Exam III Monday, November 27, 2:15-3:35PM Please be sure to show your work where it is requested. If no work is shown where it is requested, you will not receive any points. Partial

More information

Direct Current (DC) Circuits

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

More information

Chapter 27. Circuits

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,

More information

Lab 6: Capacitors and Resistor-Capacitor Circuits Phy208 Spr 2008 Name Section

Lab 6: Capacitors and Resistor-Capacitor Circuits Phy208 Spr 2008 Name Section : Capacitors and Resistor-Capacitor Circuits Phy208 Spr 2008 Name Section Your TA will use this sheet to score your lab. It is to be turned in at the end of lab. You must use complete sentences and clearly

More information

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

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

More information

RC, RL, and LCR Circuits

RC, RL, and LCR Circuits RC, RL, and LCR Circuits EK307 Lab Note: This is a two week lab. Most students complete part A in week one and part B in week two. Introduction: Inductors and capacitors are energy storage devices. They

More information

Chapter 19 Lecture Notes

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

More information

As light level increases, resistance decreases. As temperature increases, resistance decreases. Voltage across capacitor increases with time LDR

As 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 information

Physics 102: Lecture 04 Capacitors (& batteries)

Physics 102: Lecture 04 Capacitors (& batteries) Physics 102: Lecture 04 Capacitors (& batteries) Physics 102: Lecture 4, Slide 1 I wish the checkpoints were given to us on material that we learned from the previous lecture, rather than on material from

More information

Electricity and Light Pre Lab Questions

Electricity and Light Pre Lab Questions Electricity and Light Pre Lab Questions The pre lab questions can be answered by reading the theory and procedure for the related lab. You are strongly encouraged to answers these questions on your own.

More information

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 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

More information

Experiment ES Estimating a Second

Experiment ES Estimating a Second Introduction: About Estimating Experiment ES Estimating a Second Before measuring and calculating comes estimation; a chance to exercise ingenuity. Often it's a matter of organizing your rough knowledge

More information

PHYS 2135 Exam II March 20, 2018

PHYS 2135 Exam II March 20, 2018 Exam Total /200 PHYS 2135 Exam II March 20, 2018 Name: Recitation Section: Five multiple choice questions, 8 points each. Choose the best or most nearly correct answer. For questions 6-9, solutions must

More information