# Physics 102: Lecture 7 RC Circuits

Size: px
Start display at page:

Transcription

1 Physics 102: Lecture 7 C Circuits Physics 102: Lecture 7, Slide 1

2 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 charge and discharge instantaneously it takes time (even if only fractions of a second). Physics 102: Lecture 7, Slide 2

3 C Circuits Used to controllably store and release energy Today: C Circuits Charging Capacitors Discharging Capacitors Intermediate Behavior Physics 102: Lecture 7, Slide 3

4 Charging Capacitors Storing energy to use later Capacitor is initially uncharged and switch is open. Switch is then closed. What is current I 0 in circuit immediately thereafter? What is current I in circuit a long time later? C S Physics 102: Lecture 7, Slide 4

5 Charging Capacitors: t = 0 Capacitor is initially uncharged and switch is open. Switch is then closed. What is current I 0 in circuit immediately thereafter? Capacitor initially uncharged Therefore V C =0 (since V=Q/C) Therefore C behaves as a wire (short circuit) Ohm s law! I 0 = / Physics 102: Lecture 7, Slide 5 C S

6 Charging Capacitors: t > 0 I 0 = / Positive charge flows Onto bottom plate (Q) Away from top plate (Q) C As charge builds up, V C rises (V C =Q/C) Loop: V C I = 0 Physics 102: Lecture 7, Slide 6 I = ( V C )/ Therefore I falls as Q rises When t is very large () I = 0: no current flow into/out of capacitor at long times V C =

7 ACT/CheckPoint 1 Both switches are initially open, and the capacitor is uncharged. What is the current through the battery just after switch S 1 is closed? 1) I b = 0 2) I b = E /(3) 3) I b = E /(2) 4) I b = E / I b 2 C S 2 S 1 Physics 102: Lecture 7, Slide 7

8 ACT/CheckPoint 3 Both switches are initially open, and the capacitor is uncharged. What is the current through the battery after switch 1 has been closed a long time? 2 1) I b = 0 2) I b = E/(3) 3) I b = E/(2) 4) I b = E/ I b C S 2 S 1 Physics 102: Lecture 7, Slide 8

9 Discharging Capacitors Time to use that stored energy! Capacitor is initially charged (Q) and switch is open. Switch is then closed. What is current I 0 in circuit immediately thereafter? What is current I in circuit a long time later? S C Physics 102: Lecture 7, Slide 9

10 Physics 102: Lecture 7, Slide 10 Discharging Capacitors Capacitor is initially charged (Q) and switch is open. Switch is then closed. What is current I 0 in circuit immediately thereafter? KL: Q/C I 0 = 0 So, I 0 = Q/C What is current I in circuit a long time later? I = 0 I C

11 ACT/CheckPoint 5 After switch 1 has been closed for a long time, it is opened and switch 2 is closed. What is the current through the right resistor just after switch 2 is closed? 2 1) I = 0 2) I = /(3) 3) I = /(2) 4) I = / C I S 1 S 2 Physics 102: Lecture 7, Slide 11

12 Summary: charging & discharging Charge (and therefore voltage) on Capacitors cannot change instantly: remember V C = Q/C Short term behavior of Capacitor: If the capacitor starts with no charge, it has no potential difference across it and acts as a wire If the capacitor starts with charge, it has a potential difference across it and acts as a battery. Long term behavior of Capacitor: Current through a Capacitor is eventually zero. If the capacitor is charging, when fully charged no current flows and capacitor acts as an open circuit If capacitor is discharging, potential difference is zero and no current flows Physics 102: Lecture 7, Slide 12

13 Q C Circuits: Charging The switches are originally open and the capacitor is uncharged. Then switch S 1 is closed. Loop: I(t) q(t) / C = 0 Just after : q =0 Capacitor is uncharged I 0 = 0 I 0 = / Long time after: I= 0 Capacitor is fully charged q /C =0 q = C q 1 C S 1 I C S 2 Intermediate (more complex) q(t) = q (1 e t/c ) I(t) = I 0 e t/c f( x) q 0.5 Physics 102: Lecture 7, Slide t

14 C Circuits: Discharging Loop: q(t) / C I(t) = 0 Just after : q=q 0 Capacitor is still fully charged q 0 / C I 0 = 0 I 0 = q 0 / (C) Long time after: I=0 Capacitor is discharged q / C = 0 q = 0 Intermediate (more complex) 1 1 C S 1 I C S 2 q(t) = q 0 e t/c I(t) = I 0 e t/c q f( x) 0.5 Physics 102: Lecture 7, Slide t x 4

15 What is the time constant? The time constant = C. Given a capacitor starting with no charge, the time constant is the amount of time an C circuit takes to charge a capacitor to about 63.2% of its final value. The time constant is the amount of time an C circuit takes to discharge a capacitor by about 63.2% of its original value. Physics 102: Lecture 7, Slide 15

16 Time Constant Demo Each circuit has a 1 F capacitor charged to 100 Volts. When the switch is closed: Which system will be brightest? Which lights will stay on longest? Which lights consumes more energy? 1 2 Physics 102: Lecture 7, Slide 16 = 2C = C/2

17 Summary of Concepts Charge (and therefore voltage) on Capacitors cannot change instantly: remember V C = Q/C Short term behavior of Capacitor: If the capacitor starts with no charge, it has no potential difference across it and acts as a wire If the capacitor starts with charge, it has a potential difference across it and acts as a battery. Long term behavior of Capacitor: Current through a Capacitor is eventually zero. If the capacitor is charging, when fully charged no current flows and capacitor acts as an open circuit. If capacitor is discharging, potential difference is zero and no current flows. Intermediate behavior: Charge and current exponentially approach their longterm values = C Physics 102: Lecture 7, Slide 17

18 Practice: defibrillator 1=1000 W I b C=1 mf body S 2 S 1 A 500 V battery is used to charge the 1 mf capacitor for 2 seconds. How much charge is stored on the capacitor? q(t) = q (1 e t/c ) q = CV = q 2 s = Physics 102: Lecture 7, Slide 18 V C = Q/C =

19 Practice: defibrillator 1=1000 W I b C=1 mf body S 2 S 1 A 500 V battery is used to charge the 1 mf capacitor for 2 seconds. How much energy is stored in the capacitor? U = Physics 102: Lecture 7, Slide 19

20 ACT: defibrillator 1=1000 W I b C=1 mf body S 2 S 1 What is the current through the patient right after S2 is closed if body =100 W? (A) 0 A (B) 4 A (C) 0.25 A Physics 102: Lecture 7, Slide 20

21 ACT: defibrillator 1=1000 W I b C=1 mf body S 2 S 1 What is the current through the patient 0.1 s after S2 is closed if body =100 W? (A) 4 A (B) 3.6 A (C) 1.5 A Physics 102: Lecture 7, Slide 21

22 C Summary Charging q(t) = q (1e t/c ) V(t) = V (1e t/c ) I(t) = I 0 e t/c Discharging q(t) = q 0 e t/c V(t) = V 0 e t/c I(t) = I 0 e t/c Time Constant = C Large means long time to charge/discharge Short term: Charge doesn t change (often zero or max) Long term: Current through capacitor is zero. Physics 102: Lecture 7, Slide 22

### Phys 102 Lecture 9 RC circuits

Phys 102 Lecture 9 RC circuits 1 Recall from last time... We solved various circuits with resistors and batteries (also capacitors and batteries) ε R 1 R 2 R 3 R 1 ε 1 ε 2 R 3 What about circuits that

### Electricity & 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

### 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

### 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

### 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

### 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.

### PHY 1214 General Physics II

PHY 1214 General Physics II Lecture 14 Grounding, RC Circuits June 27, 2005 Weldon J. Wilson Professor of Physics & Engineering Howell Hall 221H wwilson@ucok.edu Lecture Schedule (Weeks 4-6) We are here.

### 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

### 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,

### Physics Tutorial - Currents and Circuits

Question 1: Ion Channels Physics Tutorial - Currents and Circuits The biochemistry that takes place inside cells depends on various elements that are dissolved in water as ions. The ions enter cells through

### 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

### 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

### Problem Solving 8: Circuits

MASSACHUSETTS INSTITUTE OF TECHNOLOGY Department of Physics OBJECTIVES Problem Solving 8: Circuits 1. To gain intuition for the behavior of DC circuits with both resistors and capacitors or inductors.

### 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

### Physics 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

### 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

### Physics 102: Lecture 06 Kirchhoff s Laws

Physics 102: Lecture 06 Kirchhoff s Laws Physics 102: Lecture 6, Slide 1 Today Last Lecture Last Time Resistors in series: R eq = R 1 R 2 R 3 Current through each is same; Voltage drop is IR i Resistors

### 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

### Inductors. Hydraulic analogy Duality with capacitor Charging and discharging. Lecture 12: Inductors

Lecture 12: nductors nductors Hydraulic analogy Duality with capacitor Charging and discharging Robert R. McLeod, University of Colorado http://hilaroad.com/camp/projects/magnet.html 99 Lecture 12: nductors

### 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

### Physics 2401 Summer 2, 2008 Exam II

Physics 2401 Summer 2, 2008 Exam II e = 1.60x10-19 C, m(electron) = 9.11x10-31 kg, ε 0 = 8.845x10-12 C 2 /Nm 2, k e = 9.0x10 9 Nm 2 /C 2, m(proton) = 1.67x10-27 kg. n = nano = 10-9, µ = micro = 10-6, m

### Lecture #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

### Your Comments. THIS IS SOOOO HARD. I get the concept and mathematical expression. But I do not get links among everything.

Your omments THIS IS SOOOO HAD. I get the concept and mathematical expression. But I do not get links among everything. ery confusing prelecture especially what happens when switches are closed/opened

### Capacitance: The ability to store separated charge C=Q/V. Capacitors! Capacitor. Capacitance Practice SPH4UW 24/08/2010 Q = CV

SPH4UW Capacitors! Capacitance: The ability to store separate charge C=Q/V Charge Q on plates V = V V B = E 0 Charge 2Q on plates V = V V B =2E 0 E=E 0 B E=2E 0 B Physics 102: Lecture 4, Slie 1 Potential

### Physics 2135 Exam 2 October 20, 2015

Exam Total / 200 Physics 2135 Exam 2 October 20, 2015 Printed Name: Rec. Sec. Letter: Five multiple choice questions, 8 points each. Choose the best or most nearly correct answer. 1. A straight wire segment

### Exam 3--PHYS 102--S14

Name: Exam 3--PHYS 102--S14 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

### [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

### Physics Investigation 10 Teacher Manual

Physics Investigation 10 Teacher Manual Observation When a light bulb is connected to a number of charged capacitors, it lights up for different periods of time. Problem What does the rate of discharging

### 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"

### 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

### Lecture 12 Chapter 28 RC Circuits Course website:

Lecture 12 Chapter 28 RC Circuits Course website: http://faculty.uml.edu/andriy_danylov/teaching/physicsii Today we are going to discuss: Chapter 28: Section 28.9 RC circuits Steady current Time-varying

### 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

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

### 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

### 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

### 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

### CIRCUIT ELEMENT: CAPACITOR

CIRCUIT ELEMENT: CAPACITOR PROF. SIRIPONG POTISUK ELEC 308 Types of Circuit Elements Two broad types of circuit elements Ati Active elements -capable of generating electric energy from nonelectric energy

### 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

### Chapter 24: Capacitance and dielectrics

Chapter 24: Capacitance and dielectrics Capacitor: a device store electric energy How to define capacitance In parallel and/or in series Electric energy stored in a capacitor Dielectric materials Capacitor:

### Fig. 1 Fig. 2. Calculate the total capacitance of the capacitors. (i) when connected as in Fig. 1. capacitance =... µf

1. Fig.1 shows two capacitors, A of capacitance 2µF, and B of capacitance 4µF, connected in parallel. Fig. 2 shows them connected in series. A two-way switch S can connect the capacitors either to a d.c.

### 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

### 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

### 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

### Capacitance and Dielectrics

Slide 1 / 39 Capacitance and Dielectrics 2011 by Bryan Pflueger Capacitors Slide 2 / 39 A capacitor is any two conductors seperated by an insulator, such as air or another material. Each conductor has

### A capacitor is a device that stores electric charge (memory devices). A capacitor is a device that stores energy E = Q2 2C = CV 2

Capacitance: Lecture 2: Resistors and Capacitors Capacitance (C) is defined as the ratio of charge (Q) to voltage (V) on an object: C = Q/V = Coulombs/Volt = Farad Capacitance of an object depends on geometry

### Physics 212. Lecture 8. Today's Concept: Capacitors. Capacitors in a circuits, Dielectrics, Energy in capacitors. Physics 212 Lecture 8, Slide 1

Physics 212 Lecture 8 Today's oncept: apacitors apacitors in a circuits, Dielectrics, Energy in capacitors Physics 212 Lecture 8, Slide 1 Simple apacitor ircuit Q +Q -Q Q= Q Battery has moved charge Q

### Physics for Scientists & Engineers 2

Electromagnetic Oscillations Physics for Scientists & Engineers Spring Semester 005 Lecture 8! We have been working with circuits that have a constant current a current that increases to a constant current

### CAPACITORS / 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

### = 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.

### Slide 1 / 26. Inductance by Bryan Pflueger

Slide 1 / 26 Inductance 2011 by Bryan Pflueger Slide 2 / 26 Mutual Inductance If two coils of wire are placed near each other and have a current passing through them, they will each induce an emf on one

### Exam 2: Tuesday, March 21, 5:00-6:00 PM

Exam 2: Tuesday, March 21, 5:-6: PM Test rooms: Instructor Sections Room Dr. Hale F, H 14 Physics Dr. Kurter B, N 125 BCH Dr. Madison K, M 199 Toomey Dr. Parris J, L B-1 Bertelsmeyer* Mr. Upshaw A, C,

### Physics 2112 Unit 11

Physics 2112 Unit 11 Today s oncept: ircuits Unit 11, Slide 1 Stuff you asked about.. what happens when one resistor is in parallel and one is in series with the capacitor Differential equations are tough

### Electric Circuits. Overview. Hani Mehrpouyan,

Electric Circuits Hani Mehrpouyan, Department of Electrical and Computer Engineering, Lecture 15 (First Order Circuits) Nov 16 th, 2015 Hani Mehrpouyan (hani.mehr@ieee.org) Boise State c 2015 1 1 Overview

### Name:... Section:... Physics 208 Quiz 8. April 11, 2008; due April 18, 2008

Name:... Section:... Problem 1 (6 Points) Physics 8 Quiz 8 April 11, 8; due April 18, 8 Consider the AC circuit consisting of an AC voltage in series with a coil of self-inductance,, and a capacitor of

### Chapter 30. Inductance. PowerPoint Lectures for University Physics, 14th Edition Hugh D. Young and Roger A. Freedman Lectures by Jason Harlow

Chapter 30 Inductance PowerPoint Lectures for University Physics, 14th Edition Hugh D. Young and Roger A. Freedman Lectures by Jason Harlow Learning Goals for Chapter 30 Looking forward at how a time-varying

### 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

### 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

### 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

### 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

### PHYSICS - CLUTCH CH 24: CAPACITORS & DIELECTRICS.

!! www.clutchprep.com CONCEPT: CAPACITORS AND CAPACITANCE A CAPACITOR is formed by two surfaces of equal/opposite charge brought close together - Separation of charge potential energy stored Connecting

### 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

### RC Circuits. Lecture 13. Chapter 31. Physics II. Course website:

Lecture 13 Chapter 31 Physics II RC Circuits Course website: http://faculty.uml.edu/andriy_danylov/teaching/physicsii Lecture Capture: http://echo360.uml.edu/danylov201415/physics2spring.html Steady current

### PHYS 202 Notes, Week 6

PHYS 202 Notes, Week 6 Greg Christian February 23 & 25, 2016 Last updated: 02/25/2016 at 12:36:40 This week we learn about electromagnetic induction. Magnetic Induction This section deals with magnetic

### PHY232 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

### 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

### Chapter 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

### Chapter 13. Capacitors

Chapter 13 Capacitors Objectives Describe the basic structure and characteristics of a capacitor Discuss various types of capacitors Analyze series capacitors Analyze parallel capacitors Analyze capacitive

### Application 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

### 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

### 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:

### Circuits 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 28.1-28.2, 28.4 - Watch Video: https://youtu.be/39vkt4cc5nu

### 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,

### 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

### Physics 115. Energy in E fields Electric Current Batteries Resistance. General Physics II. Session 21

Physics 115 General Physics II Session 21 Energy in E fields Electric Current Batteries Resistance R. J. Wilkes Email: phy115a@u.washington.edu Home page: http://courses.washington.edu/phy115a/ 5/6/14

### 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

### Physics 248, Spring 2009 Lab 7: Capacitors and RC-Decay

Name Section Physics 248, Spring 2009 Lab 7: Capacitors and RC-Decay Your TA will use this sheet to score your lab. It is to be turned in at the end of lab. To receive full credit you must use complete

### 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

### PHYS 202. Lecture 7 Professor Stephen Thornton February 9, 2006

PHYS 202 Lecture 7 Professor Stephen Thornton February 9, 2006 Reading Quiz What is the result when we break a thin bar magnet in two pieces? 1. One piece has only a N pole. The other piece only a S pole.

### MTE 2: Ch :30-7pm on Mar 26

MTE 2: Ch 2103 5:30-7pm on Mar 26 Contact me and Prof. Rzchowski after this lecture for Alternate Exams (also by email asap!) 2:30-4pm 6:00-7:30pm on Mar 26 Office hrs change this week Wed morning 1 Contents

### Lecture 16 - Circuit Problems

Lecture 16 - Circuit Problems A Puzzle... Crash Course in Circuits Compute the change in voltage from point A to point B (in other words, the voltage difference V B - V A ) in the following cases. Current

### Physics 24 Exam 2 March 18, 2014

Exam Total / 200 Physics 24 Exam 2 March 18, 2014 Printed Name: Rec. Sec. Letter: Five multiple choice questions, 8 points each. Choose the best or most nearly correct answer. 1. You need to store electrical

### PES 1120 Spring 2014, Spendier Lecture 35/Page 1

PES 0 Spring 04, Spendier Lecture 35/Page Today: chapter 3 - LC circuits We have explored the basic physics of electric and magnetic fields and how energy can be stored in capacitors and inductors. We

### 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

### Chapter 26: Direct-Current Circuits (Part 2)

Chapter 26: Direct-Current Circuits (Part 2) Electrical measuring instruments (con d) RC circuits Electrical Safety Phys 2435: Chap. 26, Pg 1 Electrical Measuring Instruments New Topic Phys 2435: Chap.

### 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

### 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

### 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

### Electricity. 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

### General Physics (PHY 2140)

General Physics (PHY 2140) Lecture 7 Electrostatics and electrodynamics Capacitance and capacitors capacitors with dielectrics Electric current current and drift speed resistance and Ohm s law http://www.physics.wayne.edu/~apetrov/phy2140/

### Physics 126 Fall 2004 Practice Exam 1. Answer will be posted about Oct. 5.

Physics 126 Fall 2004 Practice Exam 1. Answer will be posted about Oct. 5. 1. Which one of the following statements best explains why tiny bits of paper are attracted to a charged rubber rod? A) Paper

### 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

### Physics 2102 Gabriela González

Physics 2102 Gabriela González Any two charged conductors form a capacitor. Capacitance : C= Q/V Simple Capacitors: Parallel plates: C = ε 0 A/d Spherical : C = ε 0 4πab/(b-a) Cylindrical: C = ε 0 2πL/ln(b/a)

### 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

### 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

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

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

### Agenda for Today. Elements of Physics II. Capacitors Parallel-plate. Charging of capacitors

Capacitors Parallel-plate Physics 132: Lecture e 7 Elements of Physics II Charging of capacitors Agenda for Today Combinations of capacitors Energy stored in a capacitor Dielectrics in capacitors Physics

### Question 1. Question 2. Question 3

Question 1 Switch S in in the figure is closed at time t = 0, to begin charging an initially uncharged capacitor of capacitance C = 18.2 μf through a resistor of resistance R = 22.3 Ω. At what time (in