Slide 1 / 50. Slide 2 / 50. Slide 3 / 50. Electromagnetic Induction and Faraday s Law. Electromagnetic Induction and Faraday s Law.

Size: px
Start display at page:

Download "Slide 1 / 50. Slide 2 / 50. Slide 3 / 50. Electromagnetic Induction and Faraday s Law. Electromagnetic Induction and Faraday s Law."

Transcription

1 Electromagnetic Induction and Faraday s Law Slide 1 / 50 Electromagnetic Induction and Faraday s Law Slide 2 / 50 Induced EMF Faraday s Law of Induction Lenz s Law EMF Induced in a Moving Conductor Changing Magnetic Flux Produces an Electric Field Induced EMF Slide 3 / 50 Almost 200 years ago, Faraday looked for evidence that a magnetic field would induce an electric current with this apparatus:

2 Induced EMF He found no evidence when the current was steady, but did see a current induced when the switch was turned on or off. Slide 4 / 50 Faraday s Law of Induction; Lenz s Law Slide 5 / 50 The induced emf in a wire loop is proportional to the rate of change of magnetic flux through the loop. Magnetic flux is defined by: F B = B^A Unit of magnetic flux: weber, Wb. 1 Wb = 1 T m 2 F is the Greek letter "phi" and stands for "flux", or flow. F B represents magnetic flux, or the flow of magnetic field through a surface. 1 What is the flux through a loop of wire if a magnetic field of 0.40 T is perpendicular to it and its area is 5.0 m 2? (always use 2 significant figures) Slide 6 / 50 F B = B^A

3 2 What is the flux through a loop of wire if a magnetic field of 0.30 T is perpendicular to it and its radius is 2.0 m? (always use 2 significant figures) F B = B^A Slide 7 / 50 In the below diagram, the magnetic field (blue) is perpendicular to the plane of the loop of wire (orange) and parallel to its normal (red) so the flux is just given by # B= BA. Slide 8 / 50 If the flux passes directly though the loop of wire, perpendicular to it, then it is a maximum and # B= BA. In this case, the magnetic field (blue) is parallel to the plane of the loop of wire (orange) and perpendicular to its normal, so the flux is just given by # B = 0. Slide 9 / 50 If the magnetic field lines don't go through the loop of wire, there is no flux.

4 Faraday s Law of Induction; Lenz s Law Slide 10 / 50 The magnetic flux is is proportional to the total number of lines passing through the loop. 3 What is the magnitude of the magnetic flux through the loop of wire shown below. The magnetic field is 1.0 T and the area of the loop of wire is 5.0 m 2. Slide 11 / 50 4 What is the magnitude of the magnetic flux through the loop of wire shown below. The magnetic field is 1.0 T and the area of the loop of wire is 5.0 m 2. Slide 12 / 50

5 Faraday s Law of Induction; Lenz s Law Slide 13 / 50 Faraday s law of induction: E is the induced emf (electromovtive force) and is measured in volts (V) N is the number of loops of wire in the coil D# Bo represents the change in the magnetic flux and is measured in Webers (Wb) is the time interval during which the flux changed and is measured in seconds (s) the "-" sign has to do with the direction of the emf, and will be discussed later Faraday s Law of Induction; Lenz s Law Slide 14 / 50 The minus sign tells us the direction of the induced EMF. Let's get back to that a little later, for right now let's determine the magnitude of the induced EMF. For instance, let's figure out the induced emf in a 8.0 m 2 coil if it is in a perpendicular 0.40T magnetic field that disappears over a time interval of 2.0s? (Let's assume there's just a single loop of wire.) What is the induced emf in a 8.0 m 2 coil (consisting of one loop) if it is perpendicular to a 0.40T magnetic field that disappears over a time interval of 2.0s? N = 1 A = 8.0 m 2 B 0 = 0.4T # Bo = B 0 A = (0.4T)(8.0 m 2 ) = 3.2W B f = 0 # Bf = B 0 A = (0)(8.0 m 2 ) = 0 = 2.0s Slide 15 / 50 D# E = -N B (# Bf - # Bo) E = -N (0-3.2Wb) E = -1 = 1.6V Alternatively s

6 What is the induced emf in a 8.0 m 2 coil (consisting of one loop) if it is perpendicular to a 0.40T magnetic field that disappears over a time interval of 2.0s? Slide 16 / 50 N = 1 A = 8.0 m 2 B 0 = 0.4T B f = 0 = 2.0s D# E = -N B DBA E = -N E = -NA DB B E = -NA f-b 0 E = -1(8.0 m 2 (0-0.40T) ) = 1.6V 2.0s The second approach works because anything that is not changing can be put in front of the delta symbol. For instance, if A is constant while B is changing: Slide 17 / 50 D# E = -N B D(BA) E = -N (BA) f - (BA) 0 E = -N (B fa f) - (B 0A 0) E = -N (B fa) - (B 0A) E = -N A(B f - B 0) E = -N In this case A f = A 0 = A this becomes: Since A is in both terms, it can be factored out But [B f - B 0] is just DB DB E = -NA The same approach allows me to factor out B if it is not changing while A is changing 5 What is the magnitude of the induced emf in a single loop 2.0m 2 coil if it is perpendicular to a 0.50T magnetic field which is turned off over a time interval of 4.0s? Slide 18 / 50

7 6 What is the magnitude of the induced emf in a ten loop coil of wire whose area is 2.0m 2 if it is perpendicular to a magnetic field which is increased from 0.30T to 1.5T over a time interval of 4.0s? Slide 19 / 50 Faraday s Law of Induction; Lenz s Law Slide 20 / 50 Magnetic flux will change if the area of the loop changes: Faraday s Law of Induction; Lenz s Law Slide 21 / 50 Magnetic flux will change if the angle between the loop and the field changes:

8 7 A 4.0m2 single loop coil of wire is initially perpendicular to a 0.60T magnetic field. It is then rotated so that it become parallel to that magnetic field 2.0s later. What is the magnitude of the induced emf? Slide 22 / 50 8 A coil of wire, consisting of 50 loops, is perpendicular to a 1.2T magnetic field. The area of the coil is increased from 0.40m 2 to 1.2m 2 over a time of 5.0s. What is the magnitude of the induced emf in the coil? Slide 23 / 50 Lenz s Law Slide 24 / 50 The minus sign tells us that the direction of the induced emf is such that the resulting current produces a magnetic field that resists the change of flux through the loop. For instance, if the external field gets weaker, the current tries to replace the "missing" external field. If the external field gets stronger, the induced current tries to opposes the "extra" external field. Only worry about the field within the loop, ignore the field outside it.

9 Lenz s Law Slide 25 / 50 Initial External Field (red).... Final External Field (red) Plus Field due to Induced Current (blue).... The current flows CCW to create a field out of the board (dots) to oppose the change in the external field Lenz s Law Slide 26 / 50 Initial External Field (red) Final External Field (red).... Plus Field due to Induced Current (blue) x x x x. x x. x. x. x. x. x. x. x. x. x. x. x x x x The current flows CW to create a field into the board (blue "x"s) to cancel the new external field (red dots) Lenz s Law Slide 27 / 50 Initial External Field (red) x x x x x x x x x x x x x x x x x x x x Final External Field (red).... Plus Field due to Induced Current (blue) x x x x x x x x. x x. x. x. x. x. x x x x x x. x. x. x. x. x. x x x x x x x x x The current flows CW to create a field into the board (blue "x"s) to cancel the new external field (red dots) and replace the old external field (red "x"s)

10 Faraday s Law of Induction; Lenz s Law Slide 28 / 50 Problem Solving: Lenz s Law Determine whether the magnetic flux is increasing, decreasing, or unchanged. The magnetic field due to the induced current points in the opposite direction to the original field if the flux is increasing; in the same direction if it is decreasing; and is zero if the flux is not changing. Use the right-hand rule to determine the direction of the current. Remember that the external field and the field due to the induced current are different. 9 A magnetic field is pointing straight up through a coil of wire. The field is suddenly turned off. What is the direction of the induced current in the wire? Slide 29 / 50 A B C D E Out of the page Into the page Clockwise Counterclockwise There is no induced current 10 A magnetic field is pointing straight up through a coil of wire. The field is suddenly doubled in magnitude. What is the direction of the induced current in the wire? Slide 30 / 50 A B C D E Out of the page Into the page Clockwise Counterclockwise There is no induced current

11 11 A coil of wire is sitting on a table top. A magnet is held above it with it's north pole pointed downwards. What is the direction of the induced current? Slide 31 / 50 A B C D E Out of the page Into the page Clockwise Counterclockwise There is no induced current 12 A coil of wire is sitting on a table top. A magnet is held above it with it's north pole pointed downwards. The magnet is released and falls towards the coil. What is the direction of the induced current? Slide 32 / 50 A B C D E Out of the page Into the page Clockwise Counterclockwise There is no induced current EMF Induced in a Moving Conductor Slide 33 / 50 This image shows another way the magnetic flux can change:

12 EMF Induced in a Moving Conductor Slide 34 / 50 The induced current is in a direction that tends to slow the moving bar it will take an external force to keep it moving. EMF Induced in a Moving Conductor The induced emf has magnitude Slide 35 / 50 EMF Induced in a Moving Conductor Slide 36 / 50 Another perspective Magnetic Force Electric Force SF = ma F B - F E = 0 qvb - qe = 0 vb = E but E = V/d vb = V/d V/d = vb V is E E = Blv but d is just l and

13 13 What is the voltage between the ends of a 100m long metal rod which is traveling at a velocity of 400 m/s perpendicularly through a 5 x 10-4 T magnetic field? Slide 37 / 50 Changing Magnetic Flux Produces an Electric Field Slide 38 / 50 A changing magnetic flux induces an electric field; this is a generalization of Faraday s law. The electric field will exist regardless of whether there are any conductors around. Electric Generators A generator is the opposite of a motor it transforms mechanical energy into electrical energy. This is an ac generator: Slide 39 / 50 The axle is rotated by an external force such as falling water or steam. The brushes are in constant electrical contact with the slip rings.

14 Electric Generators Slide 40 / 50 A dc generator is similar, except that it has a split-ring commutator instead of slip rings. Transformers and Transmission of Power Slide 41 / 50 A transformer consists of two coils, either interwoven or linked by an iron core. A changing emf in one induces an emf in the other. The ratio of the emfs is equal to the ratio of the number of turns in each coil: Transformers and Transmission of Power Slide 42 / 50 This is a step-up transformer the emf in the secondary coil is larger than the emf in the primary:

15 Transformers and Transmission of Power Slide 43 / 50 Energy must be conserved; therefore, in the absence of losses, the ratio of the currents must be the inverse of the ratio of turns: P in = P out I in V in = I out V out I primary V primary = I secondary V secondary I secondary V primary = I primary V secondary I secondary N primary = I primary N secondary Transformers and Transmission of Power Slide 44 / 50 Transformers work only if the current is changing; this is one reason why electricity is transmitted as ac. Applications of Induction: Sound Systems, Computer Memory, Seismograph, GFCI Slide 45 / 50 This microphone works by induction; the vibrating membrane induces an emf in the coil

16 Applications of Induction: Sound Systems, Computer Memory, Seismograph, GFCI Slide 46 / 50 Differently magnetized areas on an audio tape or disk induce signals in the read/write heads Applications of Induction: Sound Systems, Computer Memory, Seismograph, GFCI Slide 47 / 50 A seismograph has a fixed coil and a magnet hung on a spring (or vice versa), and records the current induced when the earth shakes. Applications of Induction: Sound Systems, Computer Memory, Seismograph, GFCI Slide 48 / 50 A ground fault circuit interrupter (GFCI) will interrupt the current to a circuit that has shorted out in a very short time, preventing electrocution.

17 Summary of Chapter 21 Slide 49 / 50 Magnetic flux: Changing magnetic flux induces emf: Induced emf produces current that opposes original flux change Changing magnetic field produces an electric field Slide 50 / 50

Slide 1 / 50. Electromagnetic Induction and Faraday s Law

Slide 1 / 50 Electromagnetic Induction and Faraday s Law Slide 2 / 50 Electromagnetic Induction and Faraday s Law Induced EMF Faraday s Law of Induction Lenz s Law EMF Induced in a Moving Conductor Changing

Electromagnetic Induction and Faraday s Law

Electromagnetic Induction and Faraday s Law Induced EMF Almost 200 years ago, Faraday looked for evidence that a magnetic field would induce an electric current with this apparatus: He found no evidence

Chapter 23 Magnetic Flux and Faraday s Law of Induction

Chapter 23 Magnetic Flux and Faraday s Law of Induction Recall: right hand rule 2 10/28/2013 Units of Chapter 23 Induced Electromotive Force Magnetic Flux Faraday s Law of Induction Lenz s Law Mechanical

FARADAY S AND LENZ LAW B O O K P G

FARADAY S AND LENZ LAW B O O K P G. 4 3 6-438 MOTIONAL EMF AND MAGNETIC FLUX (DERIVIATION) Motional emf = vbl Let a conducting rod being moved through a magnetic field B During time t 0 the rod has been

Ch. 23 Electromagnetic Induction, AC Circuits, And Electrical Technologies

Ch. 23 Electromagnetic Induction, AC Circuits, And Electrical Technologies Induced emf - Faraday s Experiment When a magnet moves toward a loop of wire, the ammeter shows the presence of a current When

AP Physics C - E & M

AP Physics C - E & M Electromagnetic Induction 2017-07-14 www.njctl.org Table of Contents: Electromagnetic Induction Click on the topic to go to that section. Induced EMF Magnetic Flux and Gauss's Law

Chapter 30. Induction and Inductance

Chapter 30 Induction and Inductance 30.2: First Experiment: 1. A current appears only if there is relative motion between the loop and the magnet (one must move relative to the other); the current disappears

Chapter 27, 28 & 29: Magnetism & Electromagnetic Induction. Magnetic flux Faraday s and Lenz s law Electromagnetic Induction Ampere s law

Chapter 27, 28 & 29: Magnetism & Electromagnetic Induction Magnetic flux Faraday s and Lenz s law Electromagnetic Induction Ampere s law 1 Magnetic Flux and Faraday s Law of Electromagnetic Induction We

PHYSICS Fall Lecture 15. Electromagnetic Induction and Faraday s Law

PHYSICS 1444-001 Fall 2012 Lecture 15 Electromagnetic Induction and Faraday s Law A current can be produced by a changing magnetic field First shown in an experiment by Michael Faraday Induced emf A primary

Electromagnetic Induction Practice Problems Homework PSI AP Physics B

Electromagnetic Induction Practice Problems Homework PSI AP Physics B Name Multiple Choice Questions 1. A square loop of wire is placed in a uniform magnetic field perpendicular to the magnetic lines.

Chapter 22. Induction

Chapter 22 Induction Induced emf A current can be produced by a changing magnetic field First shown in an experiment by Michael Faraday A primary coil is connected to a battery A secondary coil is connected

COLLEGE PHYSICS Chapter 23 ELECTROMAGNETIC INDUCTION, AC CIRCUITS, AND ELECTRICAL TECHNOLOGIES

COLLEGE PHYSICS Chapter 23 ELECTROMAGNETIC INDUCTION, AC CIRCUITS, AND ELECTRICAL TECHNOLOGIES Induced emf: Faraday s Law and Lenz s Law We observe that, when a magnet is moved near a conducting loop,

AP Physics C Unit 11: Electromagnetic Induction. Part 1 - Faraday s Law and Lenz s Law

AP Physics C Unit 11: Electromagnetic Induction Part 1 - Faraday s Law and Lenz s Law What is E/M Induction? Electromagnetic Induction is the process of using magnetic fields to produce voltage, and in

Chapter 12. Magnetism and Electromagnetism

Chapter 12 Magnetism and Electromagnetism 167 168 AP Physics Multiple Choice Practice Magnetism and Electromagnetism SECTION A Magnetostatics 1. Four infinitely long wires are arranged as shown in the

ELECTROMAGNETIC INDUCTION AND FARADAY S LAW

ELECTROMAGNETIC INDUCTION AND FARADAY S LAW Magnetic Flux The emf is actually induced by a change in the quantity called the magnetic flux rather than simply py by a change in the magnetic field Magnetic

Application Of Faraday s Law Dr Miguel Cavero September 2, 2014 Application Of Faraday s Law September 2, 2014 1 / 23 The PHYS120 Exam will be divided into three sections as follows: Section A: Short Questions

C. Incorrect! Use the formula for magnetic flux. This is the product of magnetic field, times area, times the angle between them.

AP Physics - Problem Drill 17: Electromagnetism Instruction: (1) Read the problem statement and answer choices carefully (2) Work the problems on paper as 1. A house has a wall that has an area of 28 m

Demo: Solenoid and Magnet. Topics. Chapter 22 Electromagnetic Induction. EMF Induced in a Moving Conductor

Topics Chapter 22 Electromagnetic Induction EMF Induced in a Moving Conductor Magnetic Flux EMF Induced in a Moving Conductor Demo: Solenoid and Magnet v 1 EMF Induced in a Moving Conductor q Work done

FXA 2008 Φ = BA. Candidates should be able to : Define magnetic flux. Define the weber (Wb). Select and use the equation for magnetic flux :

1 Candidates should be able to : Define magnetic flux. Define the weber (Wb). Select and use the equation for magnetic flux : Φ = BAcosθ MAGNETIC FLUX (Φ) As we have already stated, a magnetic field is

General Physics (PHY 2140)

General Physics (PHY 2140) Lecture 15 Electricity and Magnetism Magnetism Applications of magnetic forces Induced voltages and induction Magnetic flux and induced emf Faraday s law http://www.physics.wayne.edu/~apetrov/phy2140/

Electromagnetic Induction

lectromagnetic Induction Induced MF We already know that moving charge (=current) causes magnetic field It also works the other way around: changing magnetic field (e.g. moving permanent magnet) causes

ElectroMagnetic Induction

ElectroMagnetic Induction Physics 1 What is E/M Induction? Electromagnetic Induction is the process of using magnetic fields to produce voltage, and in a complete circuit, a current. Michael Faraday first

Revision Guide for Chapter 15

Revision Guide for Chapter 15 Contents tudent s Checklist Revision otes Transformer... 4 Electromagnetic induction... 4 Generator... 5 Electric motor... 6 Magnetic field... 8 Magnetic flux... 9 Force on

LECTURE 23 INDUCED EMF. Instructor: Kazumi Tolich

LECTURE 23 INDUCED EMF Instructor: Kazumi Tolich Lecture 23 2 Reading chapter 23.1 to 23.4. Induced emf Magnetic flux Faraday s law Lenz s law Quiz: 1 3 Consider the circuits shown. Which of the following

Sliding Conducting Bar

Motional emf, final For equilibrium, qe = qvb or E = vb A potential difference is maintained between the ends of the conductor as long as the conductor continues to move through the uniform magnetic field

PHY 1214 General Physics II

PHY 1214 General Physics II Lecture 20 Magnetic Flux and Faraday s Law July 6-7, 2005 Weldon J. Wilson Professor of Physics & Engineering Howell Hall 221H wwilson@ucok.edu Lecture Schedule (Weeks 4-6)

PHY101: Major Concepts in Physics I

Welcome back to PHY101: Major Concepts in Physics I Photo: J. M. Schwarz Announcements In class today we will finish Chapter 20 (sections 3, 4, and 7). and then move to Chapter 13 (the first six sections).

Chapter 5: Electromagnetic Induction

Chapter 5: Electromagnetic Induction 5.1 Magnetic Flux 5.1.1 Define and use magnetic flux Magnetic flux is defined as the scalar product between the magnetic flux density, B with the vector of the area,

Our goal for today. 1. To go over the pictorial approach to Lenz s law.

Our goal for today 1. To go over the pictorial approach to Lenz s law. Lenz s Law Exposing a coil or loop to a changing magnetic flux will generate a current if the circuit is complete. The direction of

General Physics II. Electromagnetic Induction and Electromagnetic Waves

General Physics II Electromagnetic Induction and Electromagnetic Waves 1 Induced emf We have seen that an electric current produces a magnetic field. Michael Faraday demonstrated that a magnetic field

Introduction. First Experiment

Course : Bsc Applied Physical Science(Computer Science) IInd Year (Semester IV) Paper no : 14 Paper title : Electromagnetic Theory Lecture No : 14 Tittle : Faraday s Law of Induction Introduction Hello

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

Magnetic flux. where θ is the angle between the magnetic field and the area vector. The unit of magnetic flux is the weber. 1 Wb = 1 T m 2.

Magnetic flux Magnetic flux is a measure of the number of magnetic field lines passing through something, such as a loop. If we define the area of the loop as a vector, with its direction perpendicular

Chapter 23 Magnetic Flux and Faraday s Law of Induction

Chapter 23 Magnetic Flux and Faraday s Law of Induction 1 Overview of Chapter 23 Induced Electromotive Force Magnetic Flux Faraday s Law of Induction Lenz s Law Mechanical Work and Electrical Energy Generators

Electricity & Optics

Physics 24100 Electricity & Optics Lecture 16 Chapter 28 sec. 1-3 Fall 2017 Semester Professor Koltick Magnetic Flux We define magnetic flux in the same way we defined electric flux: φ e = n E da φ m =

Agenda for Today. Elements of Physics II. Forces on currents

Forces on currents Physics 132: Lecture e 14 Elements of Physics II Agenda for Today Currents are moving charges Torque on current loop Torque on rotated loop Currents create B-fields Adding magnetic fields

Physics 11b Lecture #13

Physics 11b Lecture #13 Faraday s Law S&J Chapter 31 Midterm #2 Midterm #2 will be on April 7th by popular vote Covers lectures #8 through #14 inclusive Textbook chapters from 27 up to 32.4 There will

Physics 54 Lecture March 1, Micro-quiz problems (magnetic fields and forces) Magnetic dipoles and their interaction with magnetic fields

Physics 54 Lecture March 1, 2012 OUTLINE Micro-quiz problems (magnetic fields and forces) Magnetic dipoles and their interaction with magnetic fields Electromagnetic induction Introduction to electromagnetic

Physics 115. Induction Induced currents. General Physics II. Session 30

Physics 115 General Physics II Session 30 Induction Induced currents R. J. Wilkes Email: phy115a@u.washington.edu Home page: http://courses.washington.edu/phy115a/ 1 Lecture Schedule Today 5/23/14 2 Physics

Can a Magnetic Field Produce a Current?

Can a Magnetic Field Produce a Current? In our study of magnetism we learned that an electric current through a wire, or moving electrically charged objects, produces a magnetic field. Could the reverse

Faraday's Law ds B B G G ΦB B ds Φ ε = d B dt

Faraday's Law ds ds ε= d Φ dt Φ Global Review Electrostatics» motion of q in external E-field» E-field generated by Σq i Magnetostatics» motion of q and i in external -field» -field generated by I Electrodynamics»

AP Physics 2 Electromagnetic Induction Multiple Choice

Slide 1 / 50 AP Physics 2 Electromagnetic Induction Multiple Choice www.njctl.org Slide 2 / 50 1 A beam of electrons travels between two parallel coils of wire, as shown in the figures above. When the

CURRENT-CARRYING CONDUCTORS / MOVING CHARGES / CHARGED PARTICLES IN CIRCULAR ORBITS

PHYSICS A2 UNIT 4 SECTION 4: MAGNETIC FIELDS CURRENT-CARRYING CONDUCTORS / MOVING CHARGES / CHARGED PARTICLES IN CIRCULAR ORBITS # Questions MAGNETIC FLUX DENSITY 1 What is a magnetic field? A region in

Chapter 23: Magnetic Flux and Faraday s Law of Induction

Chapter 3: Magnetic Flux and Faraday s Law of Induction Answers Conceptual Questions 6. Nothing. In this case, the break prevents a current from circulating around the ring. This, in turn, prevents the

Physics 201. Professor P. Q. Hung. 311B, Physics Building. Physics 201 p. 1/1

Physics 201 p. 1/1 Physics 201 Professor P. Q. Hung 311B, Physics Building Physics 201 p. 2/1 Magnetic flux What is a magnetic flux? This is very similar to the concept of an electric flux through an area

Electromagnetic Induction

Electromagnetic Induction Name Section Theory Electromagnetic induction employs the concept magnetic flux. Consider a conducting loop of area A in a magnetic field with magnitude B. The flux Φ is proportional

Chapter 30. Induction and Inductance

Chapter 30 Induction and Inductance 30.2: First Experiment: 1. A current appears only if there is relative motion between the loop and the magnet (one must move relative to the other); the current disappears

Faraday s Law. Lecture 17. Chapter 33. Physics II. Course website:

Lecture 17 Chapter 33 Physics II Faraday s Law Course website: http://faculty.uml.edu/andriy_danylov/teaching/physicsii Lecture Capture: http://echo360.uml.edu/danylov201415/physics2spring.html Electromagnetic

PHYSICS 1B. Today s lecture: Motional emf. and. Lenz s Law. Electricity & Magnetism

PHYSICS 1B Today s lecture: Motional emf and Lenz s Law Electricity & Magnetism PHYSICS 1B Faraday s Law Applications of Faraday s Law - GFCI A GFCI is a Ground Fault Circuit Interrupter. It is designed

Faraday s Law. Lecture 17. Chapter 33. Physics II. Course website:

Lecture 17 Chapter 33 Physics II Faraday s Law Course website: http://faculty.uml.edu/andriy_danylov/teaching/physicsii Electromagnetic induction We saw that a magnetic field could be produced with an

Electromagnetics in Medical Physics

Electromagnetics in Medical Physics Part 4. Biomagnetism Tong In Oh Department of Biomedical Engineering Impedance Imaging Research Center (IIRC) Kyung Hee University Korea tioh@khu.ac.kr Dot Product (Scalar

PS I AP Physics 2 Electromagnetic Induction Multiple Choice Questions

PS I AP Physics 2 Electromagnetic Induction Multiple Choice Questions 1. A beam of electrons travels between two parallel coils of wire, as shown in the figures above. When the coils do not carry a current,

Version The diagram below represents lines of magnetic flux within a region of space.

1. The diagram below represents lines of magnetic flux within a region of space. 5. The diagram below shows an electromagnet made from a nail, a coil of insulated wire, and a battery. The magnetic field

Chapter 21 Lecture Notes

Chapter 21 Lecture Notes Physics 2424 - Strauss Formulas: Φ = BA cosφ E = -N Φ/ t Faraday s Law E = Bvl E = NABω sinωt M = (N 2 Φ 2 )/I 1 E 2 = -M I 1 / t L = NΦ/I E = -L I/ t L = µ 0 n 2 A l Energy =

Physics 169. Luis anchordoqui. Kitt Peak National Observatory. Monday, March 27, 17

Physics 169 Kitt Peak National Observatory Luis anchordoqui 1 Question teady electric current can give steady magnetic field Because of symmetry between electricity and magnetism we can ask: teady magnetic

PHYSICS. Chapter 30 Lecture FOR SCIENTISTS AND ENGINEERS A STRATEGIC APPROACH 4/E RANDALL D. KNIGHT

PHYSICS FOR SCIENTISTS AND ENGINEERS A STRATEGIC APPROACH 4/E Chapter 30 Lecture RANDALL D. KNIGHT Chapter 30 Electromagnetic Induction IN THIS CHAPTER, you will learn what electromagnetic induction is

21 MAGNETIC FORCES AND MAGNETIC FIELDS

CHAPTER 1 MAGNETIC FORCES AND MAGNETIC FIELDS ANSWERS TO FOCUS ON CONCEPTS QUESTIONS 1 (d) Right-Hand Rule No 1 gives the direction of the magnetic force as x for both drawings A and B In drawing C, the

Revision Guide for Chapter 15

Revision Guide for Chapter 15 Contents Revision Checklist Revision otes Transformer...4 Electromagnetic induction...4 Lenz's law...5 Generator...6 Electric motor...7 Magnetic field...9 Magnetic flux...

a) head-on view b) side view c) side view Use the right hand rule for forces to confirm the direction of the force in each case.

Electromagnetism Magnetic Force on a Wire Magnetic Field around a Bar Magnet Direction of magnetic field lines: the direction that the North pole of a small test compass would point if placed in the field

Can a Magnetic Field Produce a Current?

Can a Magnetic Field Produce a Current? In our study of magnetism we learned that an electric current through a wire, or moving electrically charged objects, produces a magnetic field. Could the reverse

Lecture 29: MON 03 NOV

Physics 2113 Jonathan Dowling Lecture 29: MON 03 NOV Ch30.1 4 Induction and Inductance I Fender Stratocaster Solenoid Pickup Magnetic Circuit Breaker As the normal operating or "rated" current flows through

Electromagnetic Induction. Bo Zhou Faculty of Science, Hokudai

Electromagnetic Induction Bo Zhou Faculty of Science, Hokudai Oersted's law Oersted s discovery in 1820 that there was a close connection between electricity and magnetism was very exciting until then,

3/31/2014. Resistors in series. Resistors in parallel. Ohm s Law. Review for Test 2. Electric Power (cont d) V IR. R constant I

Ohm s Law eview for Test Ohm s law states that the current flowing through a piece of material is proportional to the voltage applied across the material. The resistance () is defined as the ratio of to.

Induction and Inductance

Induction and Inductance Key Contents Faraday s law: induced emf Induction and energy transfer Inductors and inductance RL circuits Magnetic energy density The First Experiment 1. A current appears only

Information for Physics 1201 Midterm I Wednesday, February 20

My lecture slides are posted at http://www.physics.ohio-state.edu/~humanic/ Information for Physics 1201 Midterm I Wednesday, February 20 1) Format: 10 multiple choice questions (each worth 5 points) and

Chapter 21 Magnetic Induction Lecture 12

Chapter 21 Magnetic Induction Lecture 12 21.1 Why is it called Electromagnetism? 21.2 Magnetic Flux and Faraday s Law 21.3 Lenz s Law and Work-Energy Principles 21.4 Inductance 21.5 RL Circuits 21.6 Energy

Induced Emf. Book pg

Induced Emf Book pg 428-432 Induced EMF Almost 200 years ago, Faraday looked for evidence that a magnetic field would induce an electric current with this apparatus: History of Induction 1819 Oersted:

Electromagnetism IB 12

Electromagnetism Magnetic Field around a Bar Magnet Direction of magnetic field lines: the direction that the North pole of a small test compass would point if placed in the field (N to S) What is the

PHYS 1442 Section 004 Lecture #14

PHYS 144 Section 004 Lecture #14 Wednesday March 5, 014 Dr. Chapter 1 Induced emf Faraday s Law Lenz Law Generator 3/5/014 1 Announcements After class pickup test if you didn t Spring break Mar 10-14 HW7

PHYSICS - GIANCOLI CALC 4E CH 29: ELECTROMAGNETIC INDUCTION.

!! www.clutchprep.com CONCEPT: ELECTROMAGNETIC INDUCTION A coil of wire with a VOLTAGE across each end will have a current in it - Wire doesn t HAVE to have voltage source, voltage can be INDUCED i V Common

Chapter 9 FARADAY'S LAW Recommended Problems:

Chapter 9 FARADAY'S LAW Recommended Problems: 5,7,9,10,11,13,15,17,20,21,28,29,31,32,33,34,49,50,52,58,63,64. Faraday's Law of Induction We learned that e. current produces magnetic field. Now we want

Physics of Everyday Phenomena. Chapter 14

Physics of Everyday Phenomena W. Thomas Griffith Juliet W. Brosing Chapter 14 Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display. Question 14.1 With magnets A) like

Unit 12: Magnetism Background Reading What causes magnetism? Have you ever wondered why certain materials can be easily magnetized while others seem to be unaffected by magnets? The properties of certain

Magnetism. and its applications

Magnetism and its applications Laws of Magnetism 1) Like magnetic poles repel, and 2) unlike poles attract. Magnetic Direction and Strength Law 3 - Magnetic force, either attractive or repelling varies

CHAPTER 29: ELECTROMAGNETIC INDUCTION

CHAPTER 29: ELECTROMAGNETIC INDUCTION So far we have seen that electric charges are the source for both electric and magnetic fields. We have also seen that these fields can exert forces on other electric

Electromagnetism Notes 1 Magnetic Fields

Electromagnetism Notes 1 Magnetic Fields Magnets can or other magnets. They are able to exert forces on each other without touching because they are surrounded by. Magnetic Flux refers to Areas with many

AP Physics Electromagnetic Wrap Up

AP Physics Electromagnetic Wrap Up Here are the glorious equations for this wonderful section. This is the equation for the magnetic force acting on a moving charged particle in a magnetic field. The angle

Electromagnetic Induction

Slide 1 / 76 Slide 2 / 76 Electromagnetic Induction www.njctl.org How to Use this File Slide 3 / 76 Each topic is composed of brief direct instruction There are formative assessment questions after every

Slide 1 / 24. Electromagnetic Induction 2011 by Bryan Pflueger

Slide 1 / 24 Electromagnetic Induction 2011 by Bryan Pflueger Slide 2 / 24 Induced Currents If we have a galvanometer attached to a coil of wire we can induce a current simply by changing the magnetic

Lenz s Law (Section 22.5)

Lenz s Law (Section 22.5) : Thursday, 25 of February 7:00 9:00 pm Rooms: Last Name Room (Armes) Seats A - F 201 122 G - R 200 221 S - Z 205 128 2016-02-21 Phys 1030 General Physics II (Gericke) 1 1) Charging

Faraday s Law. Underpinning of Much Technology

Module 21: Faraday s Law 1 Faraday s Law Fourth (Final) Maxwell s Equation Underpinning of Much Technology 2 Demonstration: Falling Magnet 3 Magnet Falling Through a Ring Link to movie Falling magnet slows

This Week. 1/22/2018 Physics 214 Summer

This Week Magnetism: Are you attracted or repelled? Where does magnetism come from? What use is magnetism? Post pictures and notes on refrigerators Electrical motors turn electricity into work Generators

CHAPTER 5 ELECTROMAGNETIC INDUCTION

CHAPTER 5 ELECTROMAGNETIC INDUCTION 1 Quick Summary on Previous Concepts Electrostatics Magnetostatics Electromagnetic Induction 2 Cases of Changing Magnetic Field Changing Field Strength in a Loop A Loop

DO PHYSICS ONLINE MOTORS AND GENERATORS FARADAY S LAW ELECTROMAGNETIC INDUCTION

DO PHYSICS ONLINE MOTORS AND GENERATORS FARADAY S LAW ELECTROMAGNETIC INDUCTION English Michael Faraday (1791 1867) who experimented with electric and magnetic phenomena discovered that a changing magnetic

Section 11: Magnetic Fields and Induction (Faraday's Discovery)

Section 11: Magnetic Fields and Induction (Faraday's Discovery) In this lesson you will describe Faraday's law of electromagnetic induction and tell how it complements Oersted's Principle express an understanding

Motional EMF. Toward Faraday's Law. Phys 122 Lecture 21

Motional EMF Toward Faraday's Law Phys 122 Lecture 21 Move a conductor in a magnetic field Conducting rail 1. ar moves 2. EMF produced 3. Current flows 4. ulb glows The ig Idea is the induced emf When

Electricity (& Magnetism)

EA Notes (Scen 101), Tillery Chapter 6 Electricity (& Magnetism) Introduction First five chapters are "Newtonian Physics", mechanical explanations based on Newton's Laws applied to explain the motion of

Induced Electric Field

Lecture 18 Chapter 33 Physics II Induced Electric Field Course website: http://faculty.uml.edu/andriy_danylov/teaching/physicsii Applications of Faraday s Law (some leftovers from the previous class) Applications

Section 11: Magnetic Fields and Induction (Faraday's Discovery)

Section 11: Magnetic Fields and Induction (Faraday's Discovery) In this lesson you will describe Faraday's law of electromagnetic induction and tell how it complements Oersted's Principle express an understanding

Introduction: Recall what the Biot-Savart Law and, more generally, Ampere s Law say: Electric Currents Create Magnetic Fields

Electromagnetic Induction I really don t like the order in which your author presents the material in this chapter, so I m going put in a slightly different order. Introduction: Recall what the Biot-Savart

AAST/AEDT. Electromagnetic Induction. If the permanent magnet is at rest, then - there is no current in a coil.

1 AP PHYSICS C AAST/AEDT Electromagnetic Induction Let us run several experiments. 1. A coil with wire is connected with the Galvanometer. If the permanent magnet is at rest, then - there is no current

Faraday s Law of Electromagnetic Induction

Faraday s Law of Electromagnetic Induction 2.1 Represent and reason The rectangular loop with a resistor is pulled at constant velocity through a uniform external magnetic field that points into the paper

Physics 30 Lesson 22 The Generator Effect

Physics 30 Lesson 22 The Generator Effect I. Electromagnetic induction Michael Faraday Refer to Pearson pages 609 to 620 for a conceptual discussion of electromagnetic induction and the generator effect.

Michael Faraday. Chapter 31. EMF Produced by a Changing Magnetic Field, 1. Induction. Faraday s Law

Michael Faraday Chapter 31 Faraday s Law Great experimental physicist and chemist 1791 1867 Contributions to early electricity include: Invention of motor, generator, and transformer Electromagnetic induction

Chapter 20: Electromagnetic Induction. PHY2054: Chapter 20 1

Chapter 20: Electromagnetic Induction PHY2054: Chapter 20 1 Electromagnetic Induction Magnetic flux Induced emf Faraday s Law Lenz s Law Motional emf Magnetic energy Inductance RL circuits Generators and

Chapter 29 Electromagnetic Induction

Chapter 29 Electromagnetic Induction In this chapter we investigate how changing the magnetic flux in a circuit induces an emf and a current. We learned in Chapter 25 that an electromotive force (E) is

Lecture 33. PHYC 161 Fall 2016

Lecture 33 PHYC 161 Fall 2016 Faraday s law of induction When the magnetic flux through a single closed loop changes with time, there is an induced emf that can drive a current around the loop: Recall

Elements of Physics II. Agenda for Today. Induced EMF. Force on moving charges Induced Current Magnetic Flux Area Vector. Physics 201: Lecture 1, Pg 1

Induced EMF Physics 132: Lecture e 21 Elements of Physics II Agenda for Today Force on moving charges Induced Current Magnetic Flux Area Vector Physics 201: Lecture 1, Pg 1 Clicker Question 11: A rectangular