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

Size: px
Start display at page:

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

Transcription

1 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 ifference is proportional to charge: Double Q Double V Q = CV Capacitor ny pair conuctors separate by a small istance. (e.g. two metal plates) Capacitor stores separate charge Positive Q on one conuctor, negative Q on other Net charge is zero Stores Energy U =(½) Q V Q=CV E Capacitance Practice How much charge is on a 0.9 F capacitor which has a potential ifference of 20olts? Q = CV= (0.9)(200) = 180 Coulombs How much energy is store in this capacitor? U = ½ Q V= ½ (180) (200) = 18,000 Joules! 1

2 Capacitance of Parallel Plate Capacitor V = E ND E = Q/(e 0 ) (Between two large plates) So: V = Q/(e 0 ) Recall: C Q/V C = e 0 / So: (For parallel plate capacitor) e 0 =1/(4pk)=8.85x10 12 /Nm 2 E V Parallel Plate Capacitor Calculate the capacitance of a parallel plate capacitor mae from two large square metal sheets 1.3 m on a sie, separate by 0.1 m. C C = e 0 / 12 ( )(1.3)(1.3) (0.1) F Dielectric Placing a ielectric between the plates increases the capacitance. Dielectric constant (k > 1) Unerstaning: Parallel Plates q q parallel plate capacitor is given a charge q. The plates are then e a small istance further apart. What happens to the charge q on each plate of the capacitor? Capacitance with ielectric C = k C 0 Capacitance without ielectric The ielectric allows the potential ifference between the plates to obtain a higher value an thus store more energy, therefore the capacitance is greater 1) Increases 2) Constant 3) Decreases Remember charge is real/physical. There is no place for the charges to go. 2

3 Unerstaning q q Unerstaning Two ientical parallel plate capacitors are shown in enview in ) of the figure. Each has a capacitance of C. parallel plate capacitor is given a charge q. The plates are then e a small istance further apart. Which of the following apply to the situation after the plates have been move? 1)The capacitance increases True False C = e 0 / C ecreases! 2)The electric fiel increases True False E= Q/(e 0 ) Constant 3)The voltage between the plates increases True False V= E 4)The energy store in the capacitor increases True False U = ½QV ) B) If the two are joine as in (B) of the figure, forming a single capacitor, what is the final capacitance? 1) 2C 2) C 3) C/2 e C 0 Voltage in Circuits Elements are connecte by wires. ny connecte region of wire has the same potential. The potential ifference across an element is the element s voltage. V wire 1 = V wire 2 = V wire 3 = 12 V V wire 4 = 1 C1 C2 C3 V C1 = V C2 = 7 V V C3 = 3 V Capacitors in Parallel Both ens connecte together by wire Same voltage: V 1 = V 2 = V eq Share Charge: Q eq = Q 1 Q 2 Total Cap: C eq = (Q 1 Q 2 )/V = C1 C2 Ceq

4 Parallel Practice 4 mf capacitor an 6 mf capacitor are connecte in parallel an charge to 5 volts. Calculate C eq, an the charge on each capacitor. C eq = C 4 C 6 Q 4 = C 4 V 4 Q 6 = C 6 V 6 = 4 mf6 mf = 10 mf = (4 mf)() = 20 mc = (6 mf)() = 30 mc Capacitors in Series Connecte entoen with NO other exits Same Charge: Q 1 = Q 2 = Q eq Share Voltage: V 1 V 2 =V eq C C C eq 1 2 Q eq = C eq V eq = (10 mf)() = 50 mc = Q 4 Q 6 C4 C6 V = Ceq Q Q Q Q C1 C2 Q Q Ceq Physics 102: Lecture 4, Slie 13 Physics 102: Lecture 4, Slie 14 Series Practice 4 mf capacitor an 6 mf capacitor are connecte in series an charge to 5 volts. Calculate C eq, an the charge on the 4 mf capacitor. C C 4mF 6mF 4 C6 2.4mF 1 eq Q = CV Q4 Q6 Qeq CV eq ( 2.4mF ( 5V 12mC Comparison: Series vs. Parallel Series Can follow a wire from one element to the other with no branches in between. Parallel Can fin a loop of wire containing both elements but no others (may have branches). Q Q Q Q C4 C6 Physics 102: Lecture 4, Slie 15 Q Q Ceq C1 C2 C1 Physics 102: Lecture 4, Slie 16 C2 4

5 Comparison: Capacitors vs. Resistors Capacitors store energy as separate charge: U=1/2QV Capacitance: ability to store separate charge: C = ke 0 / Voltage etermines charge: V=Q/C Resistors issipate energy as power: P=VI Resistance: how ifficult it is for charges to get through: R = r L / Voltage etermines current: V=IR Don t mix capacitor an resistor equations! Battery Electromotive Force Maintains potential ifference V Not constant power Not constant current Does NOT prouce or supply charges, just pushes them. Unerstaning circuit consists of three initially uncharge capacitors,, an, which are then connecte to a battery of emf E. The capacitors obtain charges q 1, q 2,q 3, an have voltages across their plates V 1, V 2, an V 3. Which Unerstaning circuit consists of three initially uncharge capacitors,, an, which are then connecte to a battery of emf E. The capacitors obtain charges q 1, q 2,q 3, an have voltages across their plates V 1, V 2, an V 3. Which 1) q 1 = q 2 2) q 2 = q 3 3) V 2 = V 3 4) E = V 1 5) V 1 < V 2 E q1 q1 q2 q2 q3 q3 E q1 q1 q2 q2 q3 q3 6) C eq > 1) q 1 = q 2 Not necessarily C1 an are NOT in series. 2) q 2 = q 3 Yes! C2 an are in series. 5

6 Unerstaning Unerstaning circuit consists of three initially uncharge capacitors,, an, which are then connecte to a battery of emf E. The capacitors obtain charges q 1, q 2,q 3, an have voltages across their plates V 1, V 2, an V 3. Which circuit consists of three initially uncharge capacitors,, an, which are then connecte to a battery of emf E. The capacitors obtain charges q 1, q 2,q 3, an have voltages across their plates V 1, V 2, an V 3. Which 10V 7V?? 10V 7V?? E 0V q1 q1 q2 q2 q3 q3 E 0V q1 q1 q2 q2 q3 q3 3) V 2 = V 3 Not necessarily, only if = 5) V 1 < V 2 Nope, V 1 > V 2. (E.g. V 1 = 100, V 2 =107 4) E = V 1 Yes! Both ens are connecte by wires 6) C eq > C1 Yes! is in parallel with 3 (C eq = 3 ) 6

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

Physics 102: Lecture 05 Circuits and Ohm s Law

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

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

PHYS 221 General Physics II

PHYS 221 General Physics II PHYS 221 General Physics II Capacitance, Dielectrics, Lightning Spring 2015 Assigne Reaing: 18.4 18.6 Lecture 5 Recap: PHYS 221 Last Lecture Electric force is conservative Electric potential energy Potential

More information

6. The total charge will be conserved, and the final potential difference across the capacitors will be the same. Q Q Q Q C C C + C C C

6. The total charge will be conserved, and the final potential difference across the capacitors will be the same. Q Q Q Q C C C + C C C Homework for the week of October. 4th week of classes. h. 4: 6, 5, 8, 7, 9,, 4, 44, 49, 58, 6 h. 5: 7, 8, 9 6. The total charge will be conserve, an the final potential ifference across the capacitors

More information

Goal of this chapter is to learn what is Capacitance, its role in electronic circuit, and the role of dielectrics.

Goal of this chapter is to learn what is Capacitance, its role in electronic circuit, and the role of dielectrics. PHYS 220, Engineering Physics, Chapter 24 Capacitance an Dielectrics Instructor: TeYu Chien Department of Physics an stronomy University of Wyoming Goal of this chapter is to learn what is Capacitance,

More information

Physics 219 Question 1 January

Physics 219 Question 1 January Lecture 6-16 Physics 219 Question 1 January 30. 2012. A (non-ideal) battery of emf 1.5 V and internal resistance 5 Ω is connected to a light bulb of resistance 50 Ω. How much power is delivered to the

More information

1. The electron volt is a measure of (A) charge (B) energy (C) impulse (D) momentum (E) velocity

1. The electron volt is a measure of (A) charge (B) energy (C) impulse (D) momentum (E) velocity AP Physics Multiple Choice Practice Electrostatics 1. The electron volt is a measure of (A) charge (B) energy (C) impulse (D) momentum (E) velocity. A soli conucting sphere is given a positive charge Q.

More information

Physics 102: Lecture 7 RC Circuits

Physics 102: Lecture 7 RC Circuits Physics 102: Lecture 7 C Circuits Physics 102: Lecture 7, Slide 1 C Circuits Circuits that have both resistors and capacitors: K Na Cl C ε K ε Na ε Cl S With resistance in the circuits, capacitors do not

More information

Where A is the plate area and d is the plate separation.

Where A is the plate area and d is the plate separation. DIELECTRICS Dielectrics an the parallel plate capacitor When a ielectric is place between the plates of a capacitor is larger for the same value of voltage. From the relation C = /V it can be seen that

More information

( ) Energy storage in CAPACITORs. q C

( ) Energy storage in CAPACITORs. q C Energy storage in CAPACITORs Charge capacitor by transferring bits of charge q at a time from bottom to top plate. Can use a battery to o this. Battery oes work which increase potential energy of capacitor.

More information

anubhavclasses.wordpress.com CBSE Solved Test Papers PHYSICS Class XII Chapter : Electrostatics

anubhavclasses.wordpress.com CBSE Solved Test Papers PHYSICS Class XII Chapter : Electrostatics anubhavclasses.worpress.com CBSE Solve Test Papers PHYSICS Class XII Chapter : Electrostatics anubhavclasses.worpress.com CBSE TEST PAPER-05 CLASS - XII PHYSICS (Unit Electrostatics). The Plates of a charge

More information

V q.. REASONING The potential V created by a point charge q at a spot that is located at a

V q.. REASONING The potential V created by a point charge q at a spot that is located at a 8. REASONING The electric potential at a istance r from a point charge q is given by Equation 9.6 as kq / r. The total electric potential at location P ue to the four point charges is the algebraic sum

More information

CAPACITANCE: CHAPTER 24. ELECTROSTATIC ENERGY and CAPACITANCE. Capacitance and capacitors Storage of electrical energy. + Example: A charged spherical

CAPACITANCE: CHAPTER 24. ELECTROSTATIC ENERGY and CAPACITANCE. Capacitance and capacitors Storage of electrical energy. + Example: A charged spherical CAPACITANCE: CHAPTER 24 ELECTROSTATIC ENERGY an CAPACITANCE Capacitance an capacitors Storage of electrical energy Energy ensity of an electric fiel Combinations of capacitors In parallel In series Dielectrics

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

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

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

More information

UNIT 4:Capacitors and Dielectric

UNIT 4:Capacitors and Dielectric UNIT 4:apacitors an Dielectric SF7 4. apacitor A capacitor is a evice that is capable of storing electric charges or electric potential energy. It is consist of two conucting plates separate by a small

More information

Chapter 24: Capacitance and Dielectrics

Chapter 24: Capacitance and Dielectrics Chapter 24: Capacitance and Dielectrics When you compress/stretch a spring, we are storing potential energy This is the mechanical method to store energy It is also possible to store electric energy as

More information

ECE341 Test 2 Your Name: Tue 11/20/2018

ECE341 Test 2 Your Name: Tue 11/20/2018 ECE341 Test Your Name: Tue 11/0/018 Problem 1 (1 The center of a soli ielectric sphere with raius R is at the origin of the coorinate. The ielectric constant of the sphere is. The sphere is homogeneously

More information

Physics 2212 K Quiz #2 Solutions Summer 2016

Physics 2212 K Quiz #2 Solutions Summer 2016 Physics 1 K Quiz # Solutions Summer 016 I. (18 points) A positron has the same mass as an electron, but has opposite charge. Consier a positron an an electron at rest, separate by a istance = 1.0 nm. What

More information

PRACTICE 4. CHARGING AND DISCHARGING A CAPACITOR

PRACTICE 4. CHARGING AND DISCHARGING A CAPACITOR PRACTICE 4. CHARGING AND DISCHARGING A CAPACITOR. THE PARALLEL-PLATE CAPACITOR. The Parallel plate capacitor is a evice mae up by two conuctor parallel plates with total influence between them (the surface

More information

PHY102 Electricity Course Summary

PHY102 Electricity Course Summary TOPIC 1 ELECTOSTTICS PHY1 Electricity Course Summary Coulomb s Law The magnitude of the force between two point charges is directly proportional to the product of the charges and inversely proportional

More information

Question 1. The figure shows four pairs of charged particles. For each pair, let V = 0 at infinity and consider V net at points on the x axis.

Question 1. The figure shows four pairs of charged particles. For each pair, let V = 0 at infinity and consider V net at points on the x axis. Question 1 The figure shows four pairs of charged particles. For each pair, let V = 0 at infinity and consider V net at points on the x axis. For which pairs is there a point at which V net = 0 between

More information

Chapter 16 Electrical Energy Capacitance. HW: 1, 2, 3, 5, 7, 12, 13, 17, 21, 25, 27 33, 35, 37a, 43, 45, 49, 51

Chapter 16 Electrical Energy Capacitance. HW: 1, 2, 3, 5, 7, 12, 13, 17, 21, 25, 27 33, 35, 37a, 43, 45, 49, 51 Chapter 16 Electrical Energy Capacitance HW: 1, 2, 3, 5, 7, 12, 13, 17, 21, 25, 27 33, 35, 37a, 43, 45, 49, 51 Electrical Potential Reminder from physics 1: Work done by a conservative force, depends only

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

Chapter 24: Capacitance and dielectrics

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:

More information

BROCK UNIVERSITY. Name: Student #: Page 1 of 8

BROCK UNIVERSITY. Name: Student #: Page 1 of 8 Name: Student #: BROCK UNIVERSITY Page 1 of 8 Mid-term Test 2: March 2010 Number of pages: 8 Course: PHYS 1P22/1P92 Number of students: 125 Examination date: 19 March 2010 Number of hours: 2 Time of Examination:

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

Chapter 24: Capacitance and Dielectrics

Chapter 24: Capacitance and Dielectrics Chapter 24: Capacitance and Dielectrics When you compress/stretch a spring, we are storing potential energy This is the mechanical method to store energy It is also possible to store electric energy as

More information

Phys102 Second Major-122 Zero Version Coordinator: Sunaidi Sunday, April 21, 2013 Page: 1

Phys102 Second Major-122 Zero Version Coordinator: Sunaidi Sunday, April 21, 2013 Page: 1 Coorinator: Sunaii Sunay, April 1, 013 Page: 1 Q1. Two ientical conucting spheres A an B carry eual charge Q, an are separate by a istance much larger than their iameters. Initially the electrostatic force

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

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

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. Review Multiple Choice Identify the letter of the choice that best completes the statement or answers the question. 1. When more devices are added to a series circuit, the total circuit resistance: a.

More 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

Capacitance. Chapter 21 Chapter 25. K = C / C o V = V o / K. 1 / Ceq = 1 / C / C 2. Ceq = C 1 + C 2

Capacitance. Chapter 21 Chapter 25. K = C / C o V = V o / K. 1 / Ceq = 1 / C / C 2. Ceq = C 1 + C 2 = Chapter 21 Chapter 25 Capacitance K = C / C o V = V o / K 1 / Ceq = 1 / C 1 + 1 / C 2 Ceq = C 1 + C 2 Copyright 25-2 Capacitance 25.01 Sketch a schematic diagram of a circuit with a parallel-plate capacitor,

More information

Louisiana State University Physics 2102, Exam 2, March 5th, 2009.

Louisiana State University Physics 2102, Exam 2, March 5th, 2009. PRINT Your Name: Instructor: Louisiana State University Physics 2102, Exam 2, March 5th, 2009. Please be sure to PRINT your name and class instructor above. The test consists of 4 questions (multiple choice),

More information

Physics 6B. Practice Final Solutions

Physics 6B. Practice Final Solutions Physics 6B Practice Final Solutions . Two speakers placed 4m apart produce sound waves with frequency 45Hz. A listener is standing m in front of the left speaker. Describe the sound that he hears. Assume

More information

Electrostatics and Charge. Creating Electric Fields

Electrostatics and Charge. Creating Electric Fields Electrostatics and Charge Creating Electric Fields Electric Charges Recall that all matter is made of atoms. Neutral atoms can acquire a charge in several different ways, all of which require movement

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

CHAPTER: 2 ELECTROSTATIC POTENTIAL AND CAPACITANCE

CHAPTER: 2 ELECTROSTATIC POTENTIAL AND CAPACITANCE CHAPTER: 2 ELECTROSTATIC POTENTIAL AND CAPACITANCE. Define electric potential at a point. *Electric potential at a point is efine as the work one to bring a unit positive charge from infinity to that point.

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

in series Devices connected in series will have the same amount of charge deposited on each capacitor. But different potential difference. That means

in series Devices connected in series will have the same amount of charge deposited on each capacitor. But different potential difference. That means Electric Field Electricity Lecture Series Electric Field: Field an area where any charged object will experience an electric force Kirchoff s Laws The electric field lines around a pair of point charges

More information

Charge The most basic quantity in an electric circuit is the electric charge. Charge is an electrical property of the atomic particles of which matter

Charge The most basic quantity in an electric circuit is the electric charge. Charge is an electrical property of the atomic particles of which matter Basic Concepts of DC Circuits Introduction An electric circuit is an interconnection of electrical elements. Systems of Units 1 Charge The most basic quantity in an electric circuit is the electric charge.

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

Capacitance and Dielectrics

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

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

AP Physics C - E & M. Slide 1 / 39 Slide 2 / 39. Slide 4 / 39. Slide 3 / 39. Slide 6 / 39. Slide 5 / 39. Capacitance and Dielectrics.

AP Physics C - E & M. Slide 1 / 39 Slide 2 / 39. Slide 4 / 39. Slide 3 / 39. Slide 6 / 39. Slide 5 / 39. Capacitance and Dielectrics. Slide 1 / 39 Slide 2 / 39 P Physics & M apacitance and ielectrics 20151205 www.njctl.org Slide 3 / 39 apacitors capacitor is any two conductors seperated by an insulator, such as air or another material.

More information

Class 6. Capacitance and Capacitors. Physics 106. Winter Press CTRL-L to view as a slide show. Class 6. Physics 106.

Class 6. Capacitance and Capacitors. Physics 106. Winter Press CTRL-L to view as a slide show. Class 6. Physics 106. and in and Energy Winter 2018 Press CTRL-L to view as a slide show. From last time: The field lines are related to the field as follows: What is the electric potential? How are the electric field and the

More information

Q1. A) 3F/8 B) F/4 C) F/2 D) F/16 E) F The charge on A will be Q 2. Ans: The charge on B will be 3 4 Q. F = k a Q r 2. = 3 8 k Q2 r 2 = 3 8 F

Q1. A) 3F/8 B) F/4 C) F/2 D) F/16 E) F The charge on A will be Q 2. Ans: The charge on B will be 3 4 Q. F = k a Q r 2. = 3 8 k Q2 r 2 = 3 8 F Phys10 Secon Major-1 Zero Version Coorinator: Sunaii Sunay, April 1, 013 Page: 1 Q1. Two ientical conucting spheres A an B carry eual charge Q, an are separate by a istance much larger than their iameters.

More information

Capacitors And Dielectrics

Capacitors And Dielectrics 1 In this small e-book we ll learn about capacitors and dielectrics in short and then we ll have some questions discussed along with their solutions. I ll also give you a practices test series which you

More information

CAPACITORS / ENERGY STORED BY CAPACITORS / CHARGING AND DISCHARGING

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

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

BROCK UNIVERSITY. Physics 1P22/1P92. Mid-term Test 2: 19 March Solutions

BROCK UNIVERSITY. Physics 1P22/1P92. Mid-term Test 2: 19 March Solutions BROCK UNIVERSITY Physics 1P22/1P92 Mid-term Test 2: 19 March 2010 Solutions 1. [6 marks] (See Page 746, CP # 24, and pages 15 16 of the posted Ch. 22 lecture notes from 4 March.) A 3.0 V potential difference

More information

PHY232 Spring 2008 Jon Pumplin (Original ppt courtesy of Remco Zegers) Direct current Circuits

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

More information

melectron= 9.1x10-31 kg e = 1.6x10-19 C MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question.

melectron= 9.1x10-31 kg e = 1.6x10-19 C MULTIPLE CHOICE. Choose the one alternative that best completes the statement or answers the question. Exam #1, PHYS 102 Name Chapters 16, 17, & 18 8 February 2006 Constants k=9x109 Nm2/C2 e o =8.85x10-12 F/m mproton=1.673x10-27 kg melectron= 9.1x10-31 kg e = 1.6x10-19 C MULTIPLE CHOICE. Choose the one

More information

PH 102 Exam I N N N N. 3. Which of the following is true for the electric force and not true for the gravitational force?

PH 102 Exam I N N N N. 3. Which of the following is true for the electric force and not true for the gravitational force? Name Date INSTRUCTIONS PH 102 Exam I 1. nswer all questions below. ll problems have equal weight. 2. Clearly mark the answer you choose by filling in the adjacent circle. 3. There will be no partial credit

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

University Physics (PHY 2326)

University Physics (PHY 2326) Chapter 23 University Physics (PHY 2326) Lecture 5 Electrostatics Electrical energy potential difference and electric potential potential energy of charged conductors Capacitance and capacitors 3/26/2015

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

Conductors & Capacitance

Conductors & Capacitance Conuctors & Capacitance PICK UP YOUR EXAM;; Average of the three classes is approximately 51. Stanar eviation is 18. It may go up (or own) by a point or two once all graing is finishe. Exam KEY is poste

More information

PH213 Chapter 24 Solutions

PH213 Chapter 24 Solutions PH213 Chapter 24 Solutions 24.12. IDENTIFY and S ET UP: Use the expression for derived in Example 24.4. Then use Eq. (24.1) to calculate Q. E XECUTE: (a) From Example 24.4, The conductor at higher potential

More information

Objects usually are charged up through the transfer of electrons from one object to the other.

Objects usually are charged up through the transfer of electrons from one object to the other. 1 Part 1: Electric Force Review of Vectors Review your vectors! You should know how to convert from polar form to component form and vice versa add and subtract vectors multiply vectors by scalars Find

More information

Physics 2B Winter 2012 Final Exam Practice

Physics 2B Winter 2012 Final Exam Practice Physics 2B Winter 2012 Final Exam Practice 1) When the distance between two charges is increased, the force between the charges A) increases directly with the square of the distance. B) increases directly

More information

General Physics II (PHYS 104) Exam 2: March 21, 2002

General Physics II (PHYS 104) Exam 2: March 21, 2002 General Physics II (PHYS 104) Exam 2: March 21, 2002 Name: Multiple Choice (3 points each): Answer the following multiple choice questions. Clearly circle the response (or responses) that provides the

More information

From last time. Attention. Capacitance. Spherical capacitor. Energy stored in capacitors. How do we charge a capacitor? Today:

From last time. Attention. Capacitance. Spherical capacitor. Energy stored in capacitors. How do we charge a capacitor? Today: Attention From last time More on electric potential an connection to Efiel How to calculate Efiel from V Capacitors an Capacitance switch off computers in the room an be prepare to a very lou noise Toay:

More information

Review from yesterday. Please answer PROBLEM 3 in Knight on page 716 while we are waiting to start. It takes 3.0 μj to move a 15nC charge from A

Review from yesterday. Please answer PROBLEM 3 in Knight on page 716 while we are waiting to start. It takes 3.0 μj to move a 15nC charge from A Review from yesterday Please answer PROBLEM 3 in Knight on page 716 while we are waiting to start. It takes 3.0 μj to move a 15nC charge from A to B 1 Review from yesterday Please answer PROBLEM 17 in

More information

shown in Fig. 4, is initially uncharged. How much energy is stored in the two capacitors after the switch S is closed for long time?

shown in Fig. 4, is initially uncharged. How much energy is stored in the two capacitors after the switch S is closed for long time? Chapter 25 Term 083 Q13. Each of the two 25-µF capacitors, as shown in Fig. 3, is initially uncharged. How many Coulombs of charge pass through ammeter A after the switch S is closed for long time? A)

More information

PES 1120 Spring 2014, Spendier Lecture 36/Page 1

PES 1120 Spring 2014, Spendier Lecture 36/Page 1 PES 0 Spring 04, Spenier ecture 36/Page Toay: chapter 3 - R circuits: Dampe Oscillation - Driven series R circuit - HW 9 ue Wenesay - FQs Wenesay ast time you stuie the circuit (no resistance) The total

More information

2013 Feb 13 Exam 1 Physics 106. Physical Constants:

2013 Feb 13 Exam 1 Physics 106. Physical Constants: 203 Feb 3 xam Physics 06 Physical onstants: proton charge = e =.60 0 9 proton mass = m p =.67 0 27 kg electron mass = m e = 9. 0 3 kg oulomb constant = k = 9 0 9 N m 2 / 2 permittivity = ǫ 0 = 8.85 0 2

More information

NAME Write you name also on the back page of this exam.

NAME Write you name also on the back page of this exam. 7/25/211 Physics 212 Exam-2 NAME Write you name also on the back page of this exam. Use o = 9 x 1 9 N.m 2 /C 2, g = 1 m/s 2 1. The figure shows the cross section of a family of parallel equipotential surfaces

More information

Sharpen thinking about connections among electric field, electric potential difference, potential energy

Sharpen thinking about connections among electric field, electric potential difference, potential energy PHYS 2015 -- Week 6 Sharpen thinking about connections among electric field, electric potential difference, potential energy Apply the ideas to capacitance and the parallel plate capacitor For exclusive

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

Physics (

Physics ( Exercises Question 2: Two charges 5 0 8 C and 3 0 8 C are located 6 cm apart At what point(s) on the line joining the two charges is the electric potential zero? Take the potential at infinity to be zero

More information

It's often useful to find all the points in a diagram that have the same voltage. E.g., consider a capacitor again.

It's often useful to find all the points in a diagram that have the same voltage. E.g., consider a capacitor again. 17-7 (SJP, Phys 22, Sp ') It's often useful to fin all the points in a iagram that have the same voltage. E.g., consier a capacitor again. V is high here V is in between, here V is low here Everywhere

More information

and the charge on a proton is +e. We never see objects that have a charge which is not a whole number multiple of this number.

and the charge on a proton is +e. We never see objects that have a charge which is not a whole number multiple of this number. Name: Physics Chapter 17 Study Guide ----------------------------------------------------------------------------------------------------- Useful Information: e = 1.6"10 #19 C k = 9 "10 9 Nm 2 C 2 $ 0

More information

Physics 2135 Exam 2 October 20, 2015

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

More information

Chapter 18. Circuit Elements, Independent Voltage Sources, and Capacitors

Chapter 18. Circuit Elements, Independent Voltage Sources, and Capacitors Chapter 18 Circuit Elements, Independent Voltage Sources, and Capacitors Ideal Wire _ + Ideal Battery Ideal Resistor Ideal Capacitor Series Parallel An ideal battery provides a constant potential difference

More information

104 Practice Exam 1-2/21/02

104 Practice Exam 1-2/21/02 104 Practice Exam 1-2/21/02 1. One mole of a substance contains 6.02 > 10 23 protons and an equal number of electrons. If the protons could somehow be separated from the electrons and placed in separate

More information

qq 1 1 q (a) -q (b) -2q (c)

qq 1 1 q (a) -q (b) -2q (c) 1... Multiple Choice uestions with One Correct Choice A hollow metal sphere of raius 5 cm is charge such that the potential on its surface to 1 V. The potential at the centre of the sphere is (a) zero

More information

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

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

More information

Physics 24 Exam 2 March 18, 2014

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

More information

CHAPTER 18 ELECTRIC POTENTIAL

CHAPTER 18 ELECTRIC POTENTIAL CHAPTER 18 ELECTRIC POTENTIAL BASIC CONCEPTS: ELECTRIC POTENTIAL ENERGY ELECTRIC POTENTIAL ELECTRIC POTENTIAL GRADIENT POTENTIAL DIFFERENCE POTENTIAL ENERGY 1 h PE = U = mgh Or PE U KE K And U + K = total

More information

Practice Exam 1. Necessary Constants and Equations: Electric force (Coulomb s Law): Electric field due to a point charge:

Practice Exam 1. Necessary Constants and Equations: Electric force (Coulomb s Law): Electric field due to a point charge: Practice Exam 1 Necessary Constants and Equations: Electric force (Coulomb s Law): Electric field due to a point charge: Electric potential due to a point charge: Electric potential energy: Capacitor energy:

More information

r where the electric constant

r where the electric constant 0. Coulomb s law a) Explain the concepts of electrons, protons, charged objects, charged up, gaining charge, losing charge, grounding and charge conservation. b) Describe the motion of point charges when

More information

Solutions to these tests are available online in some places (but not all explanations are good)...

Solutions to these tests are available online in some places (but not all explanations are good)... The Physics GRE Sample test put out by ETS https://www.ets.org/s/gre/pdf/practice_book_physics.pdf OSU physics website has lots of tips, and 4 additional tests http://www.physics.ohiostate.edu/undergrad/ugs_gre.php

More information

WELCOME TO PERIOD 14. Homework Exercise #13 is due today. Watch video 3 Edison s Miracle of Light for class discussion next Tuesday or Wednesday.

WELCOME TO PERIOD 14. Homework Exercise #13 is due today. Watch video 3 Edison s Miracle of Light for class discussion next Tuesday or Wednesday. WELCOME TO PERIOD 14 Homework Exercise #13 is due today. Watch video 3 Edison s Miracle of Light for class discussion next Tuesday or Wednesday. PHYSICS 1103 PERIOD 14 What is an electric circuit? How

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

Physics 2B Notes - Capacitors Spring 2018

Physics 2B Notes - Capacitors Spring 2018 Definition of a Capacitor Special Case: Parallel Plate Capacitor Capacitors in Series or Parallel Capacitor Network Definition of a Capacitor Webassign Chapter 0: 8, 9, 3, 4, 5 A capacitor is a device

More information

Get Solution of These Packages & Learn by Video Tutorials on

Get Solution of These Packages & Learn by Video Tutorials on Get Solution of These Packages & Learn by Vieo Tutorials on www.mathsbysuhag.com FREE Downloa Stuy Package from website: www.tekolasses.com & www.mathsbysuhag.com. INTRODUTION APAIT ITANE A capacitor can

More information

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

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,

More information

r where the electric constant

r where the electric constant 1.0 ELECTROSTATICS At the end of this topic, students will be able to: 10 1.1 Coulomb s law a) Explain the concepts of electrons, protons, charged objects, charged up, gaining charge, losing charge, charging

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

Designing Information Devices and Systems I Spring 2018 Lecture Notes Note 16

Designing Information Devices and Systems I Spring 2018 Lecture Notes Note 16 EECS 16A Designing Information Devices an Systems I Spring 218 Lecture Notes Note 16 16.1 Touchscreen Revisite We ve seen how a resistive touchscreen works by using the concept of voltage iviers. Essentially,

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

Lecture 12. Energy, Force, and Work in Electro- and Magneto-Quasistatics

Lecture 12. Energy, Force, and Work in Electro- and Magneto-Quasistatics Lecture 1 Energy, Force, an ork in Electro an MagnetoQuasistatics n this lecture you will learn: Relationship between energy, force, an work in electroquasistatic an magnetoquasistatic systems ECE 303

More information

ABCD42BEF F2 F8 5 4D658 CC89

ABCD42BEF F2 F8 5 4D658 CC89 ABCD BEF F F D CC Vetri Velan GSI, Physics 7B Miterm 2: Problem Solution. Outsie sphere, E looks like a point charge. E = The total charge on the sphere is Q sphere = ρ 4 3 πr3 Thus, outsie the sphere,

More information

EXAM REVIEW ON MONDAY

EXAM REVIEW ON MONDAY EXAM REVIEW ON MONDAY 6:5 8:5 PM McCarty A Room G86 By JJ Stankowicz Also, formula sheet has been posted. PHY049: Chapter 5 Capacitance calculation review +q q Why do we always consider only +q and q pairs?

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

Capacitors II. Physics 2415 Lecture 9. Michael Fowler, UVa

Capacitors II. Physics 2415 Lecture 9. Michael Fowler, UVa Capacitors II Physics 2415 Lecture 9 Michael Fowler, UVa Today s Topics First, some review then Storing energy in a capacitor How energy is stored in the electric field Dielectrics: why they strengthen

More information

Designing Information Devices and Systems I Spring 2017 Official Lecture Notes Note 13

Designing Information Devices and Systems I Spring 2017 Official Lecture Notes Note 13 EES 6A Designing Information Devices an Systems I Spring 27 Official Lecture Notes Note 3 Touchscreen Revisite We ve seen how a resistive touchscreen works by using the concept of voltage iviers. Essentially,

More information