Uniform Electric Fields

Size: px
Start display at page:

Download "Uniform Electric Fields"

Transcription

1 Uniform Electric Fields The figure shows an electric field that is the same in strength and direction at every point in a region of space. This is called a uniform electric field. The easiest way to produce a uniform electric field is with a parallel-plate capacitor. Slide 26-74

2 Motion of a Charged Particle in an Electric Field Consider a particle of charge q and mass m at a point where an electric field E has been produced by other charges, the source charges. The electric field exerts a force F on q qe. Slide 26-79

3 Motion of a Charged Particle in an Electric Field The electric field exerts a force F on q qe on a charged particle. If this is the only force acting on q, it causes the charged particle to accelerate with In a uniform field, the acceleration is constant: Slide 26-80

4 Example 1 Two 2.0-cm-diameter disks face each other, 1.0 mm apart. They are charged to ±10 nc. A proton is shot from the negative disk toward the positive disk. What launch speed must the proton have to just barely reach the positive plate?

5 QuickCheck A proton is moving to the right in a vertical electric field. A very short time later, the proton s velocity is Slide 26-82

6 QuickCheck Which electric field is responsible for the proton s trajectory? A. B. C. D. Slide 26-84

7 Example 2 An electron is launched at a 45º angle with a speed of 5.0 x 10 6 m/s from the positive plate of the parallel-plate capacitor shown. The electron lands 4.0 cm away. What is the electric field strength inside the capacitor? What is the smallest possible spacing between the plates?

8 Dipoles in a Uniform Electric Field The figure shows an electric dipole placed in a uniform external electric field. The net force on the dipole is zero. The electric field exerts a torque on the dipole which causes it to rotate. Slide 26-86

9 Dipoles in a Uniform Electric Field The figure shows an electric dipole placed in a uniform external electric field. The torque causes the dipole to rotate until it is aligned with the electric field, as shown. Notice that the positive end of the dipole is in the direction in which E points. Slide 26-87

10 QuickCheck Which dipole experiences no net force in the electric field? A. A. Dipole A. B. Dipole B. C. Dipole C. D. All three dipoles. B. C. Slide 26-88

11 QuickCheck Which dipole experiences no net torque in the electric field? A. A. Dipole A. B. Dipole B. C. Dipole C. D. All three dipoles. B. C. Slide 26-90

12 Dipoles in a Uniform Electric Field The figure shows a sample of permanent dipoles, such as water molecules, in an external electric field. All the dipoles rotate until they are aligned with the electric field. This is the mechanism by which the sample becomes polarized. Slide 26-92

13 The Torque on a Dipole The torque on a dipole placed in a uniform external electric field is Slide 26-93

14 Dipoles in a Nonuniform Electric Field How will the dipole shown behave in the presence of the point charge shown? A. Rotate cw B. Rotate ccw C. Move to the left D. Move to the right E. More than one of the above. Slide 26-99

15 Example 3 Dipole Problem Three charges are placed at the corners of the triangle as shown in the figure below. Is the triangle in equilibrium? If so, explain why. If not, draw the equilibrium orientation. In equilibrium, will the triangle move to the right, to the left, or remain in place? Explain.

16 Electric Field of a Charged Cylinder Suppose we knew only two things about electric fields: 1. The field points away from positive charges, toward negative charges. 2. An electric field exerts a force on a charged particle. From this information alone, what can we deduce about the electric field of an infinitely long charged cylinder? All we know is that this charge is positive, and that it has cylindrical symmetry. Slide 27-19

17 Cylindrical Symmetry An infinitely long charged cylinder is symmetric with respect to: Translation parallel to the cylinder axis. Rotation by an angle about the cylinder axis. Reflections in any plane containing or perpendicular to the cylinder axis. The symmetry of the electric field must match the symmetry of the charge distribution. Slide 27-20

18 Electric Field of a Charged Cylinder Could the field look like the figure below? (Imagine this picture rotated about the axis.) The next slide shows what the field would look like reflected in a plane perpendicular to the axis (left to right). Slide 27-21

19 Electric Field of a Charged Cylinder This reflection, which does not make any change in the charge distribution itself, does change the electric field. Therefore, the electric field of a cylindrically symmetric charge distribution cannot have a component parallel to the cylinder axis. Slide 27-22

20 Electric Field of a Charged Cylinder Could the field look like the figure below? (Here we re looking down the axis of the cylinder.) The next slide shows what the field would look like reflected in a plane containing the axis (left to right). Slide 27-23

21 Electric Field of a Charged Cylinder This reflection, which does not make any change in the charge distribution itself, does change the electric field. Therefore, the electric field of a cylindrically symmetric charge distribution cannot have a component tangent to the circular cross section. Slide 27-24

22 Electric Field of a Charged Cylinder Based on symmetry arguments alone, an infinitely long charged cylinder must have a radial electric field, as shown below. This is the one electric field shape that matches the symmetry of the charge distribution. Side view End view Slide 27-25

23 Planar Symmetry There are three fundamental symmetries; the first is planar symmetry. Planar symmetry involves symmetry with respect to: Translation parallel to the plane. Rotation about any line perpendicular to the plane. Reflection in the plane. Slide 27-26

24 Cylindrical Symmetry There are three fundamental symmetries; the second is cylindrical symmetry. Cylindrical symmetry involves symmetry with respect to: Translation parallel to the axis. Rotation about the axis. Reflection in any plane containing or perpendicular to the axis. Slide 27-27

25 Spherical Symmetry There are three fundamental symmetries; the third is spherical symmetry. Spherical symmetry involves symmetry with respect to: Rotation about any axis which passes through the center point. Reflection in any plane containing the center point. Slide 27-28

26 Example 4 The figures show two cross sections of two infinitely long coaxial cylinders. The inner cylinder has a positive charge, the outer cylinder has an equal negative charge. Draw the correct electric field vectors using symmetry.

27 The Concept of Flux Consider a box surrounding a region of space. We can t see into the box, but we know there is an outward-pointing electric field passing through every surface. Since electric fields point away from positive charges, we can conclude that the box must contain net positive electric charge. Slide 27-29

28 The Concept of Flux Consider a box surrounding a region of space. We can t see into the box, but we know there is an inward-pointing electric field passing through every surface. Since electric fields point toward negative charges, we can conclude that the box must contain net negative electric charge. Slide 27-30

29 The Concept of Flux Consider a box surrounding a region of space. We can t see into the box, but we know that the electric field points into the box on the left, and an equal electric field points out of the box on the right. Since this external electric field is not altered by the contents of the box, the box must contain zero net electric charge. Slide 27-31

30 This box contains A. no net charge. B. a net negative charge. C. a net positive charge.

31 Example 5 What type of net charge does the box below possess? What electric field strength must be present through the front if a negative charge is inside? Which direction?

3/22/2016. Chapter 27 Gauss s Law. Chapter 27 Preview. Chapter 27 Preview. Chapter Goal: To understand and apply Gauss s law. Slide 27-2.

3/22/2016. Chapter 27 Gauss s Law. Chapter 27 Preview. Chapter 27 Preview. Chapter Goal: To understand and apply Gauss s law. Slide 27-2. Chapter 27 Gauss s Law Chapter Goal: To understand and apply Gauss s law. Slide 27-2 Chapter 27 Preview Slide 27-3 Chapter 27 Preview Slide 27-4 1 Chapter 27 Preview Slide 27-5 Chapter 27 Preview Slide

More information

PHYSICS. Chapter 24 Lecture FOR SCIENTISTS AND ENGINEERS A STRATEGIC APPROACH 4/E RANDALL D. KNIGHT

PHYSICS. Chapter 24 Lecture FOR SCIENTISTS AND ENGINEERS A STRATEGIC APPROACH 4/E RANDALL D. KNIGHT PHYSICS FOR SCIENTISTS AND ENGINEERS A STRATEGIC APPROACH 4/E Chapter 24 Lecture RANDALL D. KNIGHT Chapter 24 Gauss s Law IN THIS CHAPTER, you will learn about and apply Gauss s law. Slide 24-2 Chapter

More information

The Electric Field of a Finite Line of Charge The Electric Field of a Finite Line of

The Electric Field of a Finite Line of Charge The Electric Field of a Finite Line of The Electric Field of a Finite Line of Charge The Electric Field of a Finite Line of Charge Example 26.3 in the text uses integration to find the electric field strength at a radial distance r in the plane

More information

9/10/2018. An Infinite Line of Charge. The electric field of a thin, uniformly charged rod may be written:

9/10/2018. An Infinite Line of Charge. The electric field of a thin, uniformly charged rod may be written: The Electric Field of a Finite Line of Charge The Electric Field of a Finite Line of Charge Example 26.3 in the text uses integration to find the electric field strength at a radial distance r in the plane

More information

Electric Field Lines. lecture 4.1.1

Electric Field Lines. lecture 4.1.1 Electric Field Lines Two protons, A and B, are in an electric field. Which proton has the larger acceleration? A. Proton A B. Proton B C. Both have the same acceleration. lecture 4.1.1 Electric Field Lines

More information

9/4/2018. Electric Field Models. Electric Field of a Point Charge. The Electric Field of Multiple Point Charges

9/4/2018. Electric Field Models. Electric Field of a Point Charge. The Electric Field of Multiple Point Charges Electric Field Models One thing learned from last chapter was that sources determine the electric field. We can understand the essential physics on the basis of simplified models of the sources of electric

More information

Electric Field Models

Electric Field Models Electric Field Models One thing learned from last chapter was that sources determine the electric field. We can understand the essential physics on the basis of simplified models of the sources of electric

More information

CPS lesson Electric Field ANSWER KEY

CPS lesson Electric Field ANSWER KEY CPS lesson Electric Field ANSWER KEY 1. A positively charged rod is brought near a conducting sphere on an insulated base. The opposite side of the sphere is briefly grounded. If the rod is now withdrawn,

More information

3. A solid conducting sphere has net charge of +6nC. At electrostatic equilibrium the electric field inside the sphere is:

3. A solid conducting sphere has net charge of +6nC. At electrostatic equilibrium the electric field inside the sphere is: Conceptual Questions. Circle the best answer. (2 points each) 1. If more electric field lines point into a balloon than come out of it, you can conclude that this balloon must contain more positive charge

More information

week 3 chapter 28 - Gauss s Law

week 3 chapter 28 - Gauss s Law week 3 chapter 28 - Gauss s Law Here is the central idea: recall field lines... + + q 2q q (a) (b) (c) q + + q q + +q q/2 + q (d) (e) (f) The number of electric field lines emerging from minus the number

More information

Questions Chapter 22 Electric Fields

Questions Chapter 22 Electric Fields Questions Chapter 22 Electric Fields 22-1 What is Physics? 22-2 The Electric Field 22-3 Electric Field Lines 22-4 Electric Field due to a Point Charge 22-5 Electric Field due to an Electric Dipole 22-6

More information

1. ELECTRIC CHARGES AND FIELDS

1. ELECTRIC CHARGES AND FIELDS 1. ELECTRIC CHARGES AND FIELDS 1. What are point charges? One mark questions with answers A: Charges whose sizes are very small compared to the distance between them are called point charges 2. The net

More information

The Basic Definition of Flux

The Basic Definition of Flux The Basic Definition of Flux Imagine holding a rectangular wire loop of area A in front of a fan. The volume of air flowing through the loop each second depends on the angle between the loop and the direction

More information

Motion of a charged particle in an electric field. Electric flux

Motion of a charged particle in an electric field. Electric flux Lecture 3 Chapter 23 Motion of a charged particle in an electric field. Electric flux 95.144 Course website: http://faculty.uml.edu/andriy_danylov/teaching/physicsii Today we are going to discuss: Chapter

More information

Flux. Flux = = va. This is the same as asking What is the flux of water through the rectangle? The answer depends on:

Flux. Flux = = va. This is the same as asking What is the flux of water through the rectangle? The answer depends on: Ch. 22: Gauss s Law Gauss s law is an alternative description of Coulomb s law that allows for an easier method of determining the electric field for situations where the charge distribution contains symmetry.

More information

A) 1, 2, 3, 4 B) 4, 3, 2, 1 C) 2, 3, 1, 4 D) 2, 4, 1, 3 E) 3, 2, 4, 1. Page 2

A) 1, 2, 3, 4 B) 4, 3, 2, 1 C) 2, 3, 1, 4 D) 2, 4, 1, 3 E) 3, 2, 4, 1. Page 2 1. Two parallel-plate capacitors with different plate separation but the same capacitance are connected in series to a battery. Both capacitors are filled with air. The quantity that is NOT the same for

More information

LECTURE 13 ELECTRIC FIELDS. Instructor: Kazumi Tolich

LECTURE 13 ELECTRIC FIELDS. Instructor: Kazumi Tolich LECTURE 13 ELECTRIC FIELDS Instructor: Kazumi Tolich Lecture 13 2 Reading chapter 19.4 to 19.5. Electric field Electric field lines Electric field 3 If a charge q " experiences an electric force F at a

More information

Chapter 4. Electrostatic Fields in Matter

Chapter 4. Electrostatic Fields in Matter Chapter 4. Electrostatic Fields in Matter 4.1. Polarization 4.2. The Field of a Polarized Object 4.3. The Electric Displacement 4.4. Linear Dielectrics 4.5. Energy in dielectric systems 4.6. Forces on

More information

E. not enough information given to decide

E. not enough information given to decide Q22.1 A spherical Gaussian surface (#1) encloses and is centered on a point charge +q. A second spherical Gaussian surface (#2) of the same size also encloses the charge but is not centered on it. Compared

More information

PHYSICS 1/23/2019. Chapter 25 Lecture. Chapter 25 The Electric Potential. Chapter 25 Preview

PHYSICS 1/23/2019. Chapter 25 Lecture. Chapter 25 The Electric Potential. Chapter 25 Preview PHYSICS FOR SCIENTISTS AND ENGINEERS A STRATEGIC APPROACH 4/E Chapter 25 Lecture RANDALL D. KNIGHT Chapter 25 The Electric Potential IN THIS CHAPTER, you will learn to use the electric potential and electric

More information

Chapter 21 Chapter 23 Gauss Law. Copyright 2014 John Wiley & Sons, Inc. All rights reserved.

Chapter 21 Chapter 23 Gauss Law. Copyright 2014 John Wiley & Sons, Inc. All rights reserved. Chapter 21 Chapter 23 Gauss Law Copyright 23-1 What is Physics? Gauss law relates the electric fields at points on a (closed) Gaussian surface to the net charge enclosed by that surface. Gauss law considers

More information

Electric Flux. If we know the electric field on a Gaussian surface, we can find the net charge enclosed by the surface.

Electric Flux. If we know the electric field on a Gaussian surface, we can find the net charge enclosed by the surface. Chapter 23 Gauss' Law Instead of considering the electric fields of charge elements in a given charge distribution, Gauss' law considers a hypothetical closed surface enclosing the charge distribution.

More information

HOMEWORK 1 SOLUTIONS

HOMEWORK 1 SOLUTIONS HOMEWORK 1 SOLUTIONS CHAPTER 18 3. REASONING AND SOLUTION The total charge to be removed is 5.0 µc. The number of electrons corresponding to this charge is N = ( 5.0 10 6 C)/( 1.60 10 19 C) = 3.1 10 13

More information

PHYS 1441 Section 002 Lecture #6

PHYS 1441 Section 002 Lecture #6 PHYS 1441 Section 002 Lecture #6 Monday, Sept. 18, 2017 Chapter 21 Motion of a Charged Particle in an Electric Field Electric Dipoles Chapter 22 Electric Flux Gauss Law with many charges What is Gauss

More information

PHYSICS - CLUTCH CH 22: ELECTRIC FORCE & FIELD; GAUSS' LAW

PHYSICS - CLUTCH CH 22: ELECTRIC FORCE & FIELD; GAUSS' LAW !! www.clutchprep.com CONCEPT: ELECTRIC CHARGE e Atoms are built up of protons, neutrons and electrons p, n e ELECTRIC CHARGE is a property of matter, similar to MASS: MASS (m) ELECTRIC CHARGE (Q) - Mass

More information

+2Q -2Q. (a) 672 N m 2 /C (b) 321 N m 2 /C (c) 105 N m 2 /C (d) 132 N m 2 /C (e) 251 N m 2 /C

+2Q -2Q. (a) 672 N m 2 /C (b) 321 N m 2 /C (c) 105 N m 2 /C (d) 132 N m 2 /C (e) 251 N m 2 /C 1. The figure below shows 4 point charges located on a circle centered about the origin. The exact locations of the charges on the circle are not given. What can you say about the electric potential created

More information

Finishing Chapter 26 on dipoles.. Electric Potential Energy of: Point Charges Dipoles Electric Potential: V Voltage: ΔV

Finishing Chapter 26 on dipoles.. Electric Potential Energy of: Point Charges Dipoles Electric Potential: V Voltage: ΔV PHY132 Introduction to Physics II Class 11 Outline: Finishing Chapter 26 on dipoles.. Electric Potential Energy of: Point Charges Dipoles Electric Potential: V Voltage: ΔV QuickCheck 26.13 Which dipole

More information

The third charge has to be along the line joining the two charges, outside the two charges, and closer to the weaker.

The third charge has to be along the line joining the two charges, outside the two charges, and closer to the weaker. Coordinator: Dr. M.F.Al-Kuhaili Thursday, uly 30, 2015 Page: 1 Q1. Two point charges q and 4q are at x = 0 and L, respectively. A third charge q is to be placed such that the net force on it is zero. What

More information

21.4 Electric Field and Electric Forces

21.4 Electric Field and Electric Forces 21.4 Electric Field and Electric Forces How do charged particles interact in empty space? How do they know the presence of each other? What goes on in the space between them? Body A produces an electric

More information

Chapter 23. Electric Fields

Chapter 23. Electric Fields Chapter 23 Electric Fields Electric Charges There are two kinds of electric charges Called positive and negative Negative charges are the type possessed by electrons Positive charges are the type possessed

More information

Chapter 19 Electric Charges, Forces, and Fields

Chapter 19 Electric Charges, Forces, and Fields Chapter 19 Electric Charges, Forces, and Fields Outline 19-1 Electric Charge 19-2 Insulators and Conductors 19-3 Coulomb s Law 19-4 The Electric Field 19-5 Electric Field Lines 19-6 Shield and Charging

More information

Roll Number SET NO. 42/1

Roll Number SET NO. 42/1 Roll Number SET NO. 4/1 INDIAN SCHOOL MUSCAT FIRST TERM EXAMINATION PHYSICS CLASS: XII Sub. Code: 04 Time Allotted: Hrs 0.04.018 Max. Marks: 70 General Instructions: 1. All questions are compulsory. There

More information

7. A capacitor has been charged by a D C source. What are the magnitude of conduction and displacement current, when it is fully charged?

7. A capacitor has been charged by a D C source. What are the magnitude of conduction and displacement current, when it is fully charged? 1. In which Orientation, a dipole placed in uniform electric field is in (a) stable (b) unstable equilibrium. 2. Two point charges having equal charges separated by 1 m in distance experience a force of

More information

How to define the direction of A??

How to define the direction of A?? Chapter Gauss Law.1 Electric Flu. Gauss Law. A charged Isolated Conductor.4 Applying Gauss Law: Cylindrical Symmetry.5 Applying Gauss Law: Planar Symmetry.6 Applying Gauss Law: Spherical Symmetry You will

More information

Coulomb s Law Pearson Education Inc.

Coulomb s Law Pearson Education Inc. Coulomb s Law Coulomb s Law: The magnitude of the electric force between two point charges is directly proportional to the product of their charges and inversely proportional to the square of the distance

More information

Copyright 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley.

Copyright 2008 Pearson Education, Inc., publishing as Pearson Addison-Wesley. Electric fields are responsible for the electric currents that flow through your computer and the nerves in your body. Electric fields also line up polymer molecules to form the images in a liquid crystal

More information

Questions Chapter 23 Gauss' Law

Questions Chapter 23 Gauss' Law Questions Chapter 23 Gauss' Law 23-1 What is Physics? 23-2 Flux 23-3 Flux of an Electric Field 23-4 Gauss' Law 23-5 Gauss' Law and Coulomb's Law 23-6 A Charged Isolated Conductor 23-7 Applying Gauss' Law:

More information

Practice Questions Exam 1/page1. PES Physics 2 Practice Exam 1 Questions. Name: Score: /.

Practice Questions Exam 1/page1. PES Physics 2 Practice Exam 1 Questions. Name: Score: /. Practice Questions Exam 1/page1 PES 110 - Physics Practice Exam 1 Questions Name: Score: /. Instructions Time allowed for this is exam is 1 hour 15 minutes 5 multiple choice (5 points) 3 to 5 written problems

More information

INDIAN SCHOOL MUSCAT FIRST TERM EXAMINATION PHYSICS

INDIAN SCHOOL MUSCAT FIRST TERM EXAMINATION PHYSICS Roll Number SET NO. General Instructions: INDIAN SCHOOL MUSCAT FIRST TERM EXAMINATION PHYSICS CLASS: XII Sub. Code: 04 Time Allotted: Hrs 0.04.08 Max. Marks: 70. All questions are compulsory. There are

More information

Sample Question: A point in empty space is near 3 charges as shown. The distances from the point to each charge are identical.

Sample Question: A point in empty space is near 3 charges as shown. The distances from the point to each charge are identical. A point in empty space is near 3 charges as shown. The distances from the point to each charge are identical. A. Draw a vector showing the direction the electric field points. y +2Q x B. What is the angle

More information

8/28/2018. The Field Model. The Field Model. The Electric Field

8/28/2018. The Field Model. The Field Model. The Electric Field The Field Model The photos show the patterns that iron filings make when sprinkled around a magnet. These patterns suggest that space itself around the magnet is filled with magnetic influence. This is

More information

Chapter 27. Gauss s Law

Chapter 27. Gauss s Law Chapter 27 Gauss s Law Electric Flux Field lines penetrating an area A perpendicular to the field The product of EA is the flux, Φ In general: Φ E = E A sin θ Electric

More information

Lecture 4-1 Physics 219 Question 1 Aug Where (if any) is the net electric field due to the following two charges equal to zero?

Lecture 4-1 Physics 219 Question 1 Aug Where (if any) is the net electric field due to the following two charges equal to zero? Lecture 4-1 Physics 219 Question 1 Aug.31.2016. Where (if any) is the net electric field due to the following two charges equal to zero? y Q Q a x a) at (-a,0) b) at (2a,0) c) at (a/2,0) d) at (0,a) and

More information

2014 F 2014 AI. 1. Why must electrostatic field at the surface of a charged conductor be normal to the surface at every point? Give reason.

2014 F 2014 AI. 1. Why must electrostatic field at the surface of a charged conductor be normal to the surface at every point? Give reason. 2014 F 1. Why must electrostatic field at the surface of a charged conductor be normal to the surface at every point? Give reason. 2. Figure shows the field lines on a positive charge. Is the work done

More information

Quiz. Chapter 15. Electrical Field. Quiz. Electric Field. Electric Field, cont. 8/29/2011. q r. Electric Forces and Electric Fields

Quiz. Chapter 15. Electrical Field. Quiz. Electric Field. Electric Field, cont. 8/29/2011. q r. Electric Forces and Electric Fields Chapter 15 Electric Forces and Electric Fields uiz Four point charges, each of the same magnitude, with varying signs as specified, are arranged at the corners of a square as shown. Which of the arrows

More information

Homework 4 PHYS 212 Dr. Amir

Homework 4 PHYS 212 Dr. Amir Homework 4 PHYS Dr. Amir. (I) A uniform electric field of magnitude 5.8 passes through a circle of radius 3 cm. What is the electric flux through the circle when its face is (a) perpendicular to the field

More information

Chapter (2) Gauss s Law

Chapter (2) Gauss s Law Chapter (2) Gauss s Law How you can determine the amount of charge within a closed surface by examining the electric field on the surface! What is meant by electric flux and how you can calculate it. How

More information

Electric Flux. To investigate this, we have to understand electric flux.

Electric Flux. To investigate this, we have to understand electric flux. Problem 21.72 A charge q 1 = +5. nc is placed at the origin of an xy-coordinate system, and a charge q 2 = -2. nc is placed on the positive x-axis at x = 4. cm. (a) If a third charge q 3 = +6. nc is now

More information

Chapter 17 & 18. Electric Field and Electric Potential

Chapter 17 & 18. Electric Field and Electric Potential Chapter 17 & 18 Electric Field and Electric Potential Electric Field Maxwell developed an approach to discussing fields An electric field is said to exist in the region of space around a charged object

More information

Electric flux. Electric Fields and Gauss s Law. Electric flux. Flux through an arbitrary surface

Electric flux. Electric Fields and Gauss s Law. Electric flux. Flux through an arbitrary surface Electric flux Electric Fields and Gauss s Law Electric flux is a measure of the number of field lines passing through a surface. The flux is the product of the magnitude of the electric field and the surface

More information

Turn in scantron You keep these question sheets

Turn in scantron You keep these question sheets Exam 1 on FEB. 20. 2018 - Physics 106 R. Schad YOUR NAME ¼À Turn in scantron You keep these question sheets 1) Electric flux through a spherical surface of radius 1m dueto a charge inside [which is the

More information

density = N A where the vector di erential aread A = ^n da, and ^n is the normaltothat patch of surface. Solid angle

density = N A where the vector di erential aread A = ^n da, and ^n is the normaltothat patch of surface. Solid angle Gauss Law Field lines and Flux Field lines are drawn so that E is tangent to the field line at every point. Field lines give us information about the direction of E, but also about its magnitude, since

More information

2 Which of the following represents the electric field due to an infinite charged sheet with a uniform charge distribution σ.

2 Which of the following represents the electric field due to an infinite charged sheet with a uniform charge distribution σ. Slide 1 / 21 1 closed surface, in the shape of a cylinder of radius R and Length L, is placed in a region with a constant electric field of magnitude. The total electric flux through the cylindrical surface

More information

Physics Lecture 13

Physics Lecture 13 Physics 113 Jonathan Dowling Physics 113 Lecture 13 EXAM I: REVIEW A few concepts: electric force, field and potential Gravitational Force What is the force on a mass produced by other masses? Kepler s

More information

CQ 1 What is alike when we say "two like charges?" Do they look, feel, or smell alike?

CQ 1 What is alike when we say two like charges? Do they look, feel, or smell alike? Ch20P Page 1 1P22/1P92 Problems (2011) Chapter 20 Electric Fields and Forces Sunday, January 09, 2011 4:50 PM CQ 1 What is alike when we say "two like charges?" Do they look, feel, or smell alike? CQ 3

More information

PHYS 2212 (Modern) Review. Electric Force and Fields

PHYS 2212 (Modern) Review. Electric Force and Fields PHYS 2212 (Modern) Review Electric Force and Fields A permanent dipole and a charged particle lie on the x-axis and are separated by a distance d as indicated in the figure. The dipole consists of positive

More information

AP Physics C Mechanics Objectives

AP Physics C Mechanics Objectives AP Physics C Mechanics Objectives I. KINEMATICS A. Motion in One Dimension 1. The relationships among position, velocity and acceleration a. Given a graph of position vs. time, identify or sketch a graph

More information

Electric Fields and Forces. Key Concepts

Electric Fields and Forces. Key Concepts Ch20Lectures Page 1 Ch20Lectures Monday, January 25, 2010 7:33 AM Chapter 20 Electric Fields and Forces Key Concepts electric charge principle of conservation of charge charge polarization, both permanent

More information

March 11. Physics 272. Spring Prof. Philip von Doetinchem

March 11. Physics 272. Spring Prof. Philip von Doetinchem Physics 272 March 11 Spring 2014 http://www.phys.hawaii.edu/~philipvd/pvd_14_spring_272_uhm.html Prof. Philip von Doetinchem philipvd@hawaii.edu Phys272 - Spring 14 - von Doetinchem - 32 Summary Magnetic

More information

PHYS 102 SECOND MAJOR EXAM TERM 011

PHYS 102 SECOND MAJOR EXAM TERM 011 PHYS 102 SECOND MAJOR EXAM TERM 011 * QUESTION NO: 1 An infinite non-conducting sheet has a surface charge density 0.10*10**(-6) C/m**2 on one side. How far apart are equipotential surfaces whose potentials

More information

Chapter 30 Sources of the magnetic field

Chapter 30 Sources of the magnetic field Chapter 30 Sources of the magnetic field Force Equation Point Object Force Point Object Field Differential Field Is db radial? Does db have 1/r2 dependence? Biot-Savart Law Set-Up The magnetic field is

More information

Chapters 21 and 22: Giancoli, 4 th Edition Electrostatics

Chapters 21 and 22: Giancoli, 4 th Edition Electrostatics Chapters 21 and 22: Giancoli, 4 th Edition Electrostatics Electric Charges Coulomb s Law and Electric force The Electric Field Electric Field Lines Electric flux Gauss Law and applications of Gauss Law

More information

PHYSICS GRADUATE SCHOOL QUALIFYING EXAMINATION

PHYSICS GRADUATE SCHOOL QUALIFYING EXAMINATION PHYSICS GRADUATE SCHOOL QUALIFYING EXAMINATION Partl INSTRUCTIONS: Work all problems. This is a closed book examination. Start each problem on a new pack of yellow paper and use only one side of each sheet.

More information

Chapter 23. Gauss Law. Copyright 2014 John Wiley & Sons, Inc. All rights reserved.

Chapter 23. Gauss Law. Copyright 2014 John Wiley & Sons, Inc. All rights reserved. Chapter 23 Gauss Law Copyright 23-1 Electric Flux Electric field vectors and field lines pierce an imaginary, spherical Gaussian surface that encloses a particle with charge +Q. Now the enclosed particle

More information

ELECTRO MAGNETIC FIELDS

ELECTRO MAGNETIC FIELDS SET - 1 1. a) State and explain Gauss law in differential form and also list the limitations of Guess law. b) A square sheet defined by -2 x 2m, -2 y 2m lies in the = -2m plane. The charge density on the

More information

free space (vacuum) permittivity [ F/m]

free space (vacuum) permittivity [ F/m] Electrostatic Fields Electrostatic fields are static (time-invariant) electric fields produced by static (stationary) charge distributions. The mathematical definition of the electrostatic field is derived

More information

Gauss s Law. Chapter 22. Electric Flux Gauss s Law: Definition. Applications of Gauss s Law

Gauss s Law. Chapter 22. Electric Flux Gauss s Law: Definition. Applications of Gauss s Law Electric Flux Gauss s Law: Definition Chapter 22 Gauss s Law Applications of Gauss s Law Uniform Charged Sphere Infinite Line of Charge Infinite Sheet of Charge Two infinite sheets of charge Phys 2435:

More information

Experiment III Electric Flux

Experiment III Electric Flux Experiment III Electric Flux When a charge distribution is symmetrical, we can use Gauss Law, a special law for electric fields. The Gauss Law method of determining the electric field depends on the idea

More information

Fall 12 PHY 122 Homework Solutions #2

Fall 12 PHY 122 Homework Solutions #2 Fall 12 PHY 122 Homework Solutions #2 Chapter 21 Problem 40 Two parallel circular rings of radius R have their centers on the x axis separated by a distance l, as shown in Fig. 21 60. If each ring carries

More information

Physics 2212 GH Quiz #2 Solutions Spring 2015

Physics 2212 GH Quiz #2 Solutions Spring 2015 Physics 2212 GH uiz #2 Solutions Spring 2015 Fundamental Charge e = 1.602 10 19 C Mass of an Electron m e = 9.109 10 31 kg Coulomb constant K = 8.988 10 9 N m 2 /C 2 Vacuum Permittivity ϵ 0 = 8.854 10

More information

Chapter 1 Electric Charges, Forces, and Fields

Chapter 1 Electric Charges, Forces, and Fields Chapter 1 Electric Charges, Forces, and Fields 1 Units of Chapter 1 Electric Charge Insulators and Conductors Coulomb s Law The Electric Field Electric Field Lines Electric Fields Generated by simple distributions

More information

PHYS102 Previous Exam Problems. Electric Fields

PHYS102 Previous Exam Problems. Electric Fields PHYS102 Previous Exam Problems CHAPTER 22 Electric Fields Electric field Point charge in an electric field Electric dipole 1. Two identical charges, each of charge Q, are positioned at points A (5.0 m,

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 23: Gauss Law. PHY2049: Chapter 23 1

Chapter 23: Gauss Law. PHY2049: Chapter 23 1 Chapter 23: Gauss Law PHY2049: Chapter 23 1 Two Equivalent Laws for Electricity Coulomb s Law equivalent Gauss Law Derivation given in Sec. 23-5 (Read!) Not derived in this book (Requires vector calculus)

More information

This is known as charge quantization. Neutral particles, like neutron and photon have zero charge.

This is known as charge quantization. Neutral particles, like neutron and photon have zero charge. Electrostatics Quantization of Charge Objectives In this lecture you will learn the following Quantization Of Charge and its measurement Coulomb's Law of force between electric charge Superposition principle

More information

Chapter 28. Gauss s Law

Chapter 28. Gauss s Law Chapter 28. Gauss s Law Using Gauss s law, we can deduce electric fields, particularly those with a high degree of symmetry, simply from the shape of the charge distribution. The nearly spherical shape

More information

CH 23. Gauss Law. A. Gauss law relates the electric fields at points on a (closed) Gaussian surface to the net charge enclosed by that surface.

CH 23. Gauss Law. A. Gauss law relates the electric fields at points on a (closed) Gaussian surface to the net charge enclosed by that surface. CH 23 Gauss Law [SHIVOK SP212] January 4, 2016 I. Introduction to Gauss Law A. Gauss law relates the electric fields at points on a (closed) Gaussian surface to the net charge enclosed by that surface.

More information

AMPERE'S LAW. B dl = 0

AMPERE'S LAW. B dl = 0 AMPERE'S LAW The figure below shows a basic result of an experiment done by Hans Christian Oersted in 1820. It shows the magnetic field produced by a current in a long, straight length of current-carrying

More information

Chapter 8. Conservation Laws. 8.3 Magnetic Forces Do No Work

Chapter 8. Conservation Laws. 8.3 Magnetic Forces Do No Work Chapter 8. Conservation Laws 8.3 Magnetic Forces Do No Work 8.2 Momentum of EM fields 8.2.1 Newton's Third Law in Electrodynamics Consider two charges, q 1 and q 2, moving with speeds v 1 and v 2 magnetic

More information

Chapter 2. Electrostatics. Introduction to Electrodynamics, 3 rd or 4 rd Edition, David J. Griffiths

Chapter 2. Electrostatics. Introduction to Electrodynamics, 3 rd or 4 rd Edition, David J. Griffiths Chapter 2. Electrostatics Introduction to Electrodynamics, 3 rd or 4 rd Edition, David J. Griffiths 2.1 The Electric Field Test charge 2.1.1 Introduction Source charges The fundamental problem that electromagnetic

More information

Gauss s Law. Name. I. The Law: , where ɛ 0 = C 2 (N?m 2

Gauss s Law. Name. I. The Law: , where ɛ 0 = C 2 (N?m 2 Name Gauss s Law I. The Law:, where ɛ 0 = 8.8510 12 C 2 (N?m 2 1. Consider a point charge q in three-dimensional space. Symmetry requires the electric field to point directly away from the charge in all

More information

Essential University Physics

Essential University Physics Essential University Physics Richard Wolfson 21 Gauss s Law PowerPoint Lecture prepared by Richard Wolfson Slide 21-1 In this lecture you ll learn To represent electric fields using field-line diagrams

More information

PHYSICS 241 TEST 1 Monday, February 17, 2003

PHYSICS 241 TEST 1 Monday, February 17, 2003 PHYSICS 241 TEST 1 Monday, February 17, 2003 This 15-question test (each question is worth approximately 6.67 points) is worth 100 points, each question is weighted equally. Please fill out the answer

More information

Chapter 24. Gauss s Law

Chapter 24. Gauss s Law Chapter 24 Gauss s Law Gauss Law Gauss Law can be used as an alternative procedure for calculating electric fields. Gauss Law is based on the inverse-square behavior of the electric force between point

More information

Chapter 24. Gauss s Law

Chapter 24. Gauss s Law Chapter 24 Gauss s Law Let s return to the field lines and consider the flux through a surface. The number of lines per unit area is proportional to the magnitude of the electric field. This means that

More information

Magnetostatics. P.Ravindran, PHY041: Electricity & Magnetism 22 January 2013: Magntostatics

Magnetostatics. P.Ravindran, PHY041: Electricity & Magnetism 22 January 2013: Magntostatics Magnetostatics Magnetic Fields We saw last lecture that some substances, particularly iron, possess a property we call magnetism that exerts forces on other magnetic materials We also saw that t single

More information

Chapter 23. Electric Fields

Chapter 23. Electric Fields Chapter 23 Electric Fields Electricity and Magnetism The laws of electricity and magnetism play a central role in the operation of many modern devices. The interatomic and intermolecular forces responsible

More information

Chapter 22 Gauss s Law

Chapter 22 Gauss s Law Chapter 22 Gauss s Law Lecture by Dr. Hebin Li Goals for Chapter 22 To use the electric field at a surface to determine the charge within the surface To learn the meaning of electric flux and how to calculate

More information

Where, ε 0 = Permittivity of free space and = Nm 2 C 2 Therefore, force

Where, ε 0 = Permittivity of free space and = Nm 2 C 2 Therefore, force Exercises Question.: What is the force between two small charged spheres having charges of 2 0 7 C and 3 0 7 C placed 30 cm apart in air? Answer.: Repulsive force of magnitude 6 0 3 N Charge on the first

More information

Chapter 21. Electric Fields

Chapter 21. Electric Fields Chapter 21 Electric Fields The Origin of Electricity The electrical nature of matter is inherent in the atoms of all substances. An atom consists of a small relatively massive nucleus that contains particles

More information

Physics 212 Exam I Sample Question Bank 2008 Multiple Choice: choose the best answer "none of the above" may can be a valid answer

Physics 212 Exam I Sample Question Bank 2008 Multiple Choice: choose the best answer none of the above may can be a valid answer Multiple Choice: choose the best answer "none of the above" may can be a valid answer The (attempted) demonstration in class with the pith balls and a variety of materials indicated that () there are two

More information

24 Gauss s Law. Gauss s Law 87:

24 Gauss s Law. Gauss s Law 87: Green Items that must be covered for the national test Blue Items from educator.com Red Items from the 8 th edition of Serway 24 Gauss s Law 24.1 Electric Flux 24.2 Gauss s Law 24.3 Application of Gauss

More information

Chapter 21: Gauss s Law

Chapter 21: Gauss s Law Chapter 21: Gauss s Law Electric field lines Electric field lines provide a convenient and insightful way to represent electric fields. A field line is a curve whose direction at each point is the direction

More information

CHAPTER 8 CONSERVATION LAWS

CHAPTER 8 CONSERVATION LAWS CHAPTER 8 CONSERVATION LAWS Outlines 1. Charge and Energy 2. The Poynting s Theorem 3. Momentum 4. Angular Momentum 2 Conservation of charge and energy The net amount of charges in a volume V is given

More information

A B C D E. 1 Two charges +Q and -3Q are placed in opposite corners of a square. The work required to move a test charge q from point A to point B is:

A B C D E. 1 Two charges +Q and -3Q are placed in opposite corners of a square. The work required to move a test charge q from point A to point B is: Slide 1 / 40 1 Two charges +Q and -3Q are placed in opposite corners of a square. The work required to move a test charge q from point to point is: dependent on the path taken from to directly proportional

More information

4. Theunitsoftheelectric eldare: A. N C 2 B. C/N C. N D. N/C E. C=m 2 ans: D Section: 22{2; Di±culty: E. Chapter 22: ELECTRIC FIELDS 377

4. Theunitsoftheelectric eldare: A. N C 2 B. C/N C. N D. N/C E. C=m 2 ans: D Section: 22{2; Di±culty: E. Chapter 22: ELECTRIC FIELDS 377 Chapter 22: ELECTRIC FIELDS 1 An electric eld is most directly related to: A the momentum of a test charge B the kinetic energy of a test charge C the potential energy of a test charge D the force acting

More information

ELECTROSTATICS (Important formulae and Concepts) I Electric charges and Coulomb s law

ELECTROSTATICS (Important formulae and Concepts) I Electric charges and Coulomb s law ELECTROSTATICS (Important formulae and Concepts) I Electric charges and Coulomb s law II Electric Field and Electric Dipole www.nrpschool.com www.nrpschool.com III ELECTRIC POTENTIAL www.nrpschool.com

More information

ELECTRIC FORCES AND ELECTRIC FIELDS

ELECTRIC FORCES AND ELECTRIC FIELDS CHATER 18 ELECTRIC FORCES AND ELECTRIC FIELDS CONCETUAL QUESTIONS 1. REASONING AND SOLUTION In Figure 18.9, the grounding wire is removed first, followed by the rod, and the sphere is left with a positive

More information

Phys 102 Lecture 3 The Electric field

Phys 102 Lecture 3 The Electric field Phys 102 Lecture 3 The Electric field 1 Today we will... Learn about the electric field Apply the superposition principle Ex: Dipole, line of charges, plane of charges Represent the E field using electric

More information

Mansfield Independent School District AP Physics C: Electricity and Magnetism Year at a Glance

Mansfield Independent School District AP Physics C: Electricity and Magnetism Year at a Glance Mansfield Independent School District AP Physics C: Electricity and Magnetism Year at a Glance First Six-Weeks Second Six-Weeks Third Six-Weeks Lab safety Lab practices and ethical practices Math and Calculus

More information