PHYS Fields and Waves

Size: px
Start display at page:

Download "PHYS Fields and Waves"

Transcription

1 PHYS 41 - Fields and Waves

2 Consider a charge moving in a magnetic field B field into plane F=ma acceleration change of direction of velocity Take F as centripetal force: 0 F qvb cos90 qvb F Centripetal v m R R mv qb Since F is perpendicular to v, the force leads to a circular motion Radius of circular motion Angular velocity: v R qb m

3 Radiation is produced by oscillating electrons Angular frequency of electrons = radiation frequency f qb m B fm q B fm q Hz kg C T Homework : Problem 7.15 and 7.1 (both 11 th and 1 th Eds.)

4 Summary of Section 7.4 Charge in a magnetic field move in circular path Radius: R mv qb Angular frequency: v R qb m Hmwk Sect. 7.4: Probls 7.15 and 7.1 (11 th and 1 th Eds.)

5 Charges pass by an area with a B and an E crossed The E field deflects + charges down The B field deflects + charges up Particles will go through undeflected if F e and F m balance each other F F qvb qe m e E v B Only those particles with v = E/B will go through undeflected Crossed B and E fields act as a velocity selector

6 Velocity selectors are used in analog TV screens J.J. Thomson used a velocity selector to study the electron: Accelerated electrons through a potential V Sent them through a v-selector with E and B adjusted to let them to go undeflected Calculated the ratio of the charge to the mass of the electron 1 1 KE ev mv m B e m E VB He received the Nobel prize for discovering that the electron was a particle E His son received it for discovering that it was a wave... Hmwk : Probl. 7.7 (11 th Ed.) or 7.5 (1 th Ed.)

7 1 1 E KE ev mv m ; v B E B B me kg 6 10 N/C 19 ev C V T Homework : Problem 7.31 (both 11 th or 1 th Eds.)

8 Summary of Section 7.5 Velocity selector v E B Ratio of charge to mass of electron e m E VB Hmwk Sect. 7.5: Problems 7.7 and 7.31 (11 th Ed.) or 7.5 and 7.31 (1 th Ed.)

9 Consider charges moving inside a conductor placed in a magnetic field B Each charge feels a force Magnitude: Direction: to the left F qvd B F qv B d V d = drift velocity Force is to the left Now obtain the total force on the whole length of wire Number of charges in length of wire n = density of charges = nla A = cross sectional area Total force in F nal qv length of wire db nqvda lb IlB

10 For cases in which B is not to perpendicular to wire F Il B F IlB sin Some examples For a segment of a wire df Idl B

11 Force on wire? F IlB sin 50 A 1 m 1. T sin N Again using vectors: Force pointing out of the plane Hmwk: Probl (11 th Ed.) or 7.36 (1 th Ed.) Solution: a) b) and c): 7.06x 10-3 N 0 ˆ 0ˆ 0 ˆ F Il B I li B cos45 i Bsin 45 j iˆ ˆj kˆ 0 I l 0 0 IlB sin 45 k 4.4 Nk B 0 0 cos 45 B sin 45 0 ˆ ˆ

12 Find the force on the three segments of wire Segment 3: length L into the plane Segment 1 Segment Segment 1: Segment 3: F ILB sin90 0 ˆj ILBj ˆ 0 F IlBsin180 0 Segment is more interesting...

13 Segment 3: x components of force cancel net force will be in the y direction F df IB dl cos x IBR x 0 d cos F df IB dl sin y y 0 IBR d sin IRB Total force on all three segments: F ILBj ˆ IRBj ˆ IB L R ˆj Homework : Problem 7.35 and 7.39 or 7.37 and 7.39 (1 th Ed.)

14 Summary of Section 7.6 Forces on current carrying conductors F Il B df Idl B Add forces Hmwk Sect. 7.6: Probls 7.34, 7.35 and 7.39 (11 th Ed.) or 7.36, 7.37 and 7.39 (1 th Ed.)

15 Consider a current loop in a B field perpendicular to current x components of force cancel y components of force cancel net force on loop will be zero Now consider a loop tilted respect to the B field Again x and y components of force cancel net force on loop will be zero but there will be a torque on loop

16 Loop tilted respect to the B field Forces in x and y cancel Forces in x form a couple Segments in y direction feel forces: F Il B F IaB in ± x Separation between these forces is and torque is then: r F bsin Fbsin IaB bsin IAB sin Bsin Or in vector form: Magnetic dipole moment is: B IA Valid for all geometries

17 Some examples What are the directions of IA and B? A current loop in a B field has potential energy: U B Bcos

18 Magnetic moment: NIA Total 30 5 A 0.05 m 1.18 Am Torque, method 1: Torque, method : Bsin sin Am T Nm 0 NIBAsin 30 5 A 1. T 0.05 m sin Nm Torque tends to rotate

19 Homework: Probls 7.4 and 7.44 (both 11 th and 1 th Eds.) Soln. 7.4: a), b) and c): 7.06x 10-3 N

20 U Bcos90 0 Initial potential energy: 0 Initial Final potential energy: 0 B cos UFinal Am T J Change in potential energy: UFinal UInitial 1.41 J Homework : Problem 7.47 (both 11 th and 1 th eds.)

21 How do magnets work? If for any loop in a uniform B field The forces in x and y cancel Forces form a couple that produces only a torque Then, how do magnets attract or repel? Magnets affect atomic loops in materials B field of magnets is not uniform Forces produced are not zero

22 Summary of Section 7.7 In loops : Forces in x and y cancel Forces in x form a couple Loops feel a torque Magnetic dipole moment is: Potential energy: B IA U B Bcos Magnets work by exerting forces on atomic loops in materials thanks to their not uniform B field Hmwk Sect. 7.7: Probls 7.4, 7.44 and 7.47 (both 11 th Ed and 1 th Eds.)

23 PHYS 41 - Fields and Waves

24

25

26 PHYS 41 - Fields and Waves

Lecture 28. PHYC 161 Fall 2016

Lecture 28. PHYC 161 Fall 2016 Lecture 28 PHYC 161 Fall 2016 CPS 27-1 At which point is the magnitude of the magnetic field the largest? A. B. C. D E. Yes, back to flux, which means back to surface integrals. Magnetic Flux We can define

More information

Chapter 27 Magnetic Field and Magnetic Forces

Chapter 27 Magnetic Field and Magnetic Forces Chapter 27 Magnetic Field and Magnetic Forces Lecture by Dr. Hebin Li Goals for Chapter 27 To study magnets and the forces they exert on each other To calculate the force that a magnetic field exerts on

More information

Today s lecture: Motion in a Uniform Magnetic Field continued Force on a Current Carrying Conductor Introduction to the Biot-Savart Law

Today s lecture: Motion in a Uniform Magnetic Field continued Force on a Current Carrying Conductor Introduction to the Biot-Savart Law PHYSICS 1B Today s lecture: Motion in a Uniform Magnetic Field continued Force on a Current Carrying Conductor Introduction to the Biot-Savart Law Electricity & Magnetism A Charged Particle in a Magnetic

More information

Magnetic field and magnetic poles

Magnetic field and magnetic poles Magnetic field and magnetic poles Magnetic Field B is analogically similar to Electric Field E Electric charges (+ and -)are in analogy to magnetic poles(north:n and South:S). Paramagnetism, Diamagnetism,

More information

Physics 169. Luis anchordoqui. Kitt Peak National Observatory. Monday, March 13, 17

Physics 169. Luis anchordoqui. Kitt Peak National Observatory. Monday, March 13, 17 Physics 169 Kitt Peak National Observatory Luis anchordoqui 1 6.1 Magnetic Field Stationary charges experienced an electric force in an electric field Moving charges experienced a magnetic force in a magnetic

More information

Magnetism. Permanent magnets Earth s magnetic field Magnetic force Motion of charged particles in magnetic fields

Magnetism. Permanent magnets Earth s magnetic field Magnetic force Motion of charged particles in magnetic fields Magnetism Permanent magnets Earth s magnetic field Magnetic force Motion of charged particles in magnetic fields Copyright The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

More information

Chapter 29. Magnetic Fields

Chapter 29. Magnetic Fields Chapter 29 Magnetic Fields A Brief History of Magnetism 13 th century BC Chinese used a compass Uses a magnetic needle Probably an invention of Arabic or Indian origin 800 BC Greeks Discovered magnetite

More information

Chapter 29. Magnetic Fields

Chapter 29. Magnetic Fields Chapter 29 Magnetic Fields Outline 29.1 Magnetic Fields and Forces 29.2 Magnetic Force Acting on a Current-Carrying Conductor 29.4 Motion of a Charged Particle in a Uniform Magnetic Field 29.5 Applications

More information

Physics 4. Magnetic Forces and Fields. Prepared by Vince Zaccone For Campus Learning Assistance Services at UCSB

Physics 4. Magnetic Forces and Fields. Prepared by Vince Zaccone For Campus Learning Assistance Services at UCSB Physics 4 Magnetic Forces and Fields What creates a magnetic field? Answer: MOVING CHARGES What is affected by a magnetic field? Answer: MOVING CHARGES We have a formula for magnetic force on a moving

More information

Chapter 21. Magnetic Forces and Magnetic Fields

Chapter 21. Magnetic Forces and Magnetic Fields Chapter 21 Magnetic Forces and Magnetic Fields 21.1 Magnetic Fields The needle of a compass is permanent magnet that has a north magnetic pole (N) at one end and a south magnetic pole (S) at the other.

More information

Magnetic Force Acting on a Current- Carrying Conductor IL B

Magnetic Force Acting on a Current- Carrying Conductor IL B Magnetic Force Acting on a Current- Carrying Conductor A segment of a current-carrying wire in a magnetic field. The magnetic force exerted on each charge making up the current is qvd and the net force

More information

Lecture 29. PHYC 161 Fall 2016

Lecture 29. PHYC 161 Fall 2016 Lecture 29 PHYC 161 Fall 2016 Magnetic Force and Torque on a Current Loop Let s look at the Net force and net torque on a current loop: df Idl B F IaB top and bottom F IbB sides But, the forces on opposite

More information

(1) I have completed at least 50% of the reading and study-guide assignments associated with the lecture, as indicated on the course schedule.

(1) I have completed at least 50% of the reading and study-guide assignments associated with the lecture, as indicated on the course schedule. iclicker Quiz (1) I have completed at least 50% of the reading and study-guide assignments associated with the lecture, as indicated on the course schedule. a) True b) False Hint: pay attention to how

More information

Physics 4B. Question 28-4 into page: a, d, e; out of page: b, c, f (the particle is negatively charged)

Physics 4B. Question 28-4 into page: a, d, e; out of page: b, c, f (the particle is negatively charged) Physics 4B Solutions to Chapter 8 HW Chapter 8: Questions: 4, 6, 10 Problems: 4, 11, 17, 33, 36, 47, 49, 51, 60, 74 Question 8-4 into page: a, d, e; out of page: b, c, f (the particle is negatively charged)

More information

PH 222-2C Fall Magnetic Field. Lecture 13. Chapter 28 (Halliday/Resnick/Walker, Fundamentals of Physics 8 th edition)

PH 222-2C Fall Magnetic Field. Lecture 13. Chapter 28 (Halliday/Resnick/Walker, Fundamentals of Physics 8 th edition) PH 222-2C Fall 2012 Magnetic Field Lecture 13 Chapter 28 (Halliday/Resnick/Walker, Fundamentals of Physics 8 th edition) 1 Chapter 28 Magnetic Fields In this chapter we will cover the following topics:

More information

Magnetic Fields. or I in the filed. ! F = q! E. ! F = q! v! B. q! v. Charge q as source. Current I as source. Gauss s Law. Ampere s Law.

Magnetic Fields. or I in the filed. ! F = q! E. ! F = q! v! B. q! v. Charge q as source. Current I as source. Gauss s Law. Ampere s Law. Magnetic Fields Charge q as source Gauss s Law Electric field E F = q E Faraday s Law Ampere-Maxwell Law Current I as source Magnetic field B Ampere s Law F = q v B Force on q in the field Force on q v

More information

Chapter 28. The Magnetic Field

Chapter 28. The Magnetic Field Chapter 28 The Magnetic Field Magnetic Field Force Exerted by a Magnetic Field Point Charge in a Magnetic Field Torques on Current Loops MFMcGraw-PHY 2426 Ch28a-Magnetic Field - Revised 10/03/2012 2 Magnetic

More information

10/24/2012 PHY 102. (FAWOLE O.G.) Good day. Here we go..

10/24/2012 PHY 102. (FAWOLE O.G.) Good day. Here we go.. Good day. Here we go.. 1 PHY102- GENERAL PHYSICS II Text Book: Fundamentals of Physics Authors: Halliday, Resnick & Walker Edition: 8 th Extended Lecture Schedule TOPICS: Dates Ch. 28 Magnetic Fields 12

More information

Magnetic Force. A vertical wire carries a current and is in a vertical magnetic field. What is the direction of the force on the wire?

Magnetic Force. A vertical wire carries a current and is in a vertical magnetic field. What is the direction of the force on the wire? Magnetic Force A vertical wire carries a current and is in a vertical magnetic field. What is the direction of the force on the wire? (a) left (b) right (c) zero (d) into the page (e) out of the page B

More information

Magnets and Electromagnetism

Magnets and Electromagnetism Review 9 Magnets and Electromagnetism 1. A 1.2 cm wire carrying a current of 0.8 A is perpendicular to a 2.4 T magnetic field. What is the magnitude of the force on the wire? 2. A 24 cm length of wire

More information

Magnetism II. Physics 2415 Lecture 15. Michael Fowler, UVa

Magnetism II. Physics 2415 Lecture 15. Michael Fowler, UVa Magnetism II Physics 2415 Lecture 15 Michael Fowler, UVa Today s Topics Force on a charged particle moving in a magnetic field Path of a charged particle moving in a magnetic field Torque on a current

More information

Lecture 32: MON 09 NOV Review Session A : Midterm 3

Lecture 32: MON 09 NOV Review Session A : Midterm 3 Physics 2113 Jonathan Dowling Lecture 32: MON 09 NOV Review Session A : Midterm 3 EXAM 03: 6PM WED 11 NOV in Cox Auditorium The exam will cover: Ch.27.4 through Ch.30 The exam will be based on: HW08 11

More information

Homework (lecture 11): 3, 5, 9, 13, 21, 25, 29, 31, 40, 45, 49, 51, 57, 62

Homework (lecture 11): 3, 5, 9, 13, 21, 25, 29, 31, 40, 45, 49, 51, 57, 62 Homework (lecture ): 3, 5, 9, 3,, 5, 9, 3, 4, 45, 49, 5, 57, 6 3. An electron that has velocity: moves through the uniform magnetic field (a) Find the force on the electron. (b) Repeat your calculation

More information

CHAPTER 27 HOMEWORK SOLUTIONS

CHAPTER 27 HOMEWORK SOLUTIONS CHAPTER 7 HOMEWORK SOLUTIONS 7.1. IDENTIFY and SET UP: Apply Eq.(7.) to calculate F. Use the cross products of unit vectors from Section 1.10. EXECUTE: v 4.1910 4 m/siˆ 3.8510 4 m/s ˆj (a) B 1.40 Tˆ i

More information

Magnetic Fields & Forces

Magnetic Fields & Forces Magnetic Fields & Forces Oersted discovered that an electric current will produce a magnetic field around conductor only a moving charge creates a magnetic field the magnetic field is circular around the

More information

CHAPTER 21 MAGNETIC FORCES AND MAGNETIC FIELDS

CHAPTER 21 MAGNETIC FORCES AND MAGNETIC FIELDS CHAPTER 21 MAGNETIC FORCES AND MAGNETIC FIELDS PROBLEMS 5. SSM REASONING According to Equation 21.1, the agnitude of the agnetic force on a oving charge is F q 0 vb sinθ. Since the agnetic field points

More information

Magnetic force and magnetic fields

Magnetic force and magnetic fields magnetar Magnetic force and magnetic fields Feb 28, 2012 Magnetic field Iron filings may be used to show the pattern of the magnetic field lines. A compass can be used to trace the field lines. The lines

More information

Gravity Electromagnetism Weak Strong

Gravity Electromagnetism Weak Strong 19. Magnetism 19.1. Magnets 19.1.1. Considering the typical bar magnet we can investigate the notion of poles and how they apply to magnets. 19.1.1.1. Every magnet has two distinct poles. 19.1.1.1.1. N

More information

Lorentz Force. Velocity Selector

Lorentz Force. Velocity Selector Lecture 9-1 Lorentz Force Let E and denote the electric and magnetic vector fields. The force F acting on a point charge q, moving with velocity v in the superimosed E fields is: F qe v This is called

More information

Brief history of Magnetism 3/5/ Magnetic force on a current carrying wire. 1. Magnetic field history: applications:

Brief history of Magnetism 3/5/ Magnetic force on a current carrying wire. 1. Magnetic field history: applications: 1. Magnetic field history: applications: PHY 114 A General Physics II 11 AM 12:15 PM Olin 101 George Holzwarth gholz@wfu.edu Main topics today (Chapt 29): B 2. Lorentz force law for charged particles moving

More information

Certain iron containing materials have been known to attract or repel each other. Compasses align to the magnetic field of earth.

Certain iron containing materials have been known to attract or repel each other. Compasses align to the magnetic field of earth. Certain iron containing materials hae been known to attract or repel each other. Compasses align to the magnetic field of earth. Analogous to positie and negatie charges, eery magnet has a north and a

More information

Chapter 27: Magnetic Field and Magnetic Forces

Chapter 27: Magnetic Field and Magnetic Forces Chapter 27: Magnetic Field and Magnetic Forces Iron ore found near Magnesia Compass needles align N-S: magnetic Poles North (South) Poles attracted to geographic North (South) Like Poles repel, Opposites

More information

Cyclotron Motion. We can also work-out the frequency of the cyclotron motion. f cyc =

Cyclotron Motion. We can also work-out the frequency of the cyclotron motion. f cyc = Cyclotron Motion We can also work-out the frequency of the cyclotron motion f cyc = qb 2πm Neil Alberding (SFU Physics) Physics 121: Optics, Electricity & Magnetism Spring 2010 1 / 1 Cyclotron Motion We

More information

Chapter 22: Magnetism

Chapter 22: Magnetism Chapter 22: Magnetism Magnets Magnets are caused by moving charges. Permanent Magnets vs. Electromagnets Magnets always have two poles, north and south. Like poles repel, opposites attract. Brent Royuk

More information

Discussion Question 7A P212, Week 7 RC Circuits

Discussion Question 7A P212, Week 7 RC Circuits Discussion Question 7A P1, Week 7 RC Circuits The circuit shown initially has the acitor uncharged, and the switch connected to neither terminal. At time t = 0, the switch is thrown to position a. C a

More information

Chapter 22: Magnetism. Brent Royuk Phys-112 Concordia University

Chapter 22: Magnetism. Brent Royuk Phys-112 Concordia University Chapter 22: Magnetism Brent Royuk Phys-112 Concordia University Magnets Magnets are caused by moving charges. Permanent Magnets vs. Electromagnets Magnets always have two poles, north and south. Like poles

More information

Physics 202, Lecture 11

Physics 202, Lecture 11 Physics 202, Lecture 11 Today s Topics Magnetic Fields and Forces (Ch. 27) Magnetic materials Magnetic forces on moving point charges Magnetic forces on currents, current loops Motion of charge in uniform

More information

Lecture 8 Magnetic Fields Chp. 29

Lecture 8 Magnetic Fields Chp. 29 Lecture 8 Magnetic Fields Chp. 29 Cartoon Magnesia, Bar Magnet with N/S Poles, Right Hand Rule Topics Magnetism is likable, Compass and diclinometer, Permanent magnets Magnetic field lines, Force on a

More information

Magnetic fields. The symbol we use for a magnetic field is B. The unit is the tesla (T). The Earth s magnetic field is about 5 x 10-5 T.

Magnetic fields. The symbol we use for a magnetic field is B. The unit is the tesla (T). The Earth s magnetic field is about 5 x 10-5 T. Magnetic fields The symbol we use for a magnetic field is B. The unit is the tesla (T). The Earth s magnetic field is about 5 x 10-5 T. Which pole of a magnet attracts the north pole of a compass? Which

More information

PHYS 1444 Section 003 Lecture #15

PHYS 1444 Section 003 Lecture #15 PHYS 1444 Section 003 Lecture #15 Monday, Oct. 24, 2005 Magnetic field Earth s magnetic field Magnetic field by electric current Magnetic force on electric current Magnetic force on a moving charge Today

More information

Problem Fig

Problem Fig Problem 27.15 An electron at point A has a speed of 1.41 x 10 6 m/s. Find (a) the magnitude and direction of the magnetic field that will cause the electron to follow the semicircular path from A to B,

More information

Magnetic Fields & Forces

Magnetic Fields & Forces Magnetic Fields & Forces Oersted discovered that an electric current will produce a magnetic field around conductor only a moving charge creates a magnetic field the magnetic field is circular around the

More information

( )( )( ) Model: The magnetic field is that of a moving charged particle. Visualize: 10 T m/a C m/s sin T. 1.

( )( )( ) Model: The magnetic field is that of a moving charged particle. Visualize: 10 T m/a C m/s sin T. 1. 33.3. Model: The magnetic field is that of a moving charged particle. Visualize: The first point is on the x-axis, with θ a = 90. The second point is on the y-axis, with θ b = 180, and the third point

More information

PHYS 1444 Section 003 Lecture #17

PHYS 1444 Section 003 Lecture #17 PHYS 1444 Section 003 Lecture #17 Tuesday, Nov. 1, 2011 Electric Current and Magnetism Magnetic Forces on Electric Current About Magnetic Field Magnetic Forces on a Moving Charge Charged Particle Path

More information

The force F on a charge q moving with velocity v through a region of space with electric field E and magnetic field B is given by: F qe qv B

The force F on a charge q moving with velocity v through a region of space with electric field E and magnetic field B is given by: F qe qv B Lorentz Forces The force F on a charge q moving with velocity v through a region of space with electric field E and magnetic field B is given by: F qe qv B F qv B B F q vbsin 2/20/2018 1 Right Hand Rule

More information

11/13/2018. The Hall Effect. The Hall Effect. The Hall Effect. Consider a magnetic field perpendicular to a flat, currentcarrying

11/13/2018. The Hall Effect. The Hall Effect. The Hall Effect. Consider a magnetic field perpendicular to a flat, currentcarrying The Hall Effect Consider a magnetic field perpendicular to a flat, currentcarrying conductor. As the charge carriers move at the drift speed v d, they will experience a magnetic force F B = ev d B perpendicular

More information

Consider a magnetic field perpendicular to a flat, currentcarrying

Consider a magnetic field perpendicular to a flat, currentcarrying The Hall Effect Consider a magnetic field perpendicular to a flat, currentcarrying conductor. As the charge carriers move at the drift speed v d, they will experience a magnetic force F B = ev d B perpendicular

More information

Magnetic Fields Permanent Magnets

Magnetic Fields Permanent Magnets 1 Magnetic Fields Permanent Magnets Magnetic fields are continuous loops leaving a North pole and entering a South pole they point in direction that an isolated North would move Highest strength near poles

More information

Chapter 27, 28 & 29: Magnetism & Electromagnetic Induction

Chapter 27, 28 & 29: Magnetism & Electromagnetic Induction Chapter 27, 28 & 29: Magnetism & Electromagnetic Induction The Magnetic Field The Magnetic Force on Moving Charges The Motion of Charged Particles in a Magnetic Field The Magnetic Force Exerted on a Current-Carrying

More information

Homework. Suggested exercises: 32.1, 32.3, 32.5, 32.7, 32.9, 32.11, 32.13, 32.15, 32.18, 32.20, 32.24, 32.28, 32.32, 32.33, 32.35, 32.37, 32.

Homework. Suggested exercises: 32.1, 32.3, 32.5, 32.7, 32.9, 32.11, 32.13, 32.15, 32.18, 32.20, 32.24, 32.28, 32.32, 32.33, 32.35, 32.37, 32. Homework Reading: Chap. 32 and Chap. 33 Suggested exercises: 32.1, 32.3, 32.5, 32.7, 32.9, 32.11, 32.13, 32.15, 32.18, 32.20, 32.24, 32.28, 32.32, 32.33, 32.35, 32.37, 32.39 Problems: 32.46, 32.48, 32.52,

More information

This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 4.0 License.

This work is licensed under a Creative Commons Attribution-Noncommercial-Share Alike 4.0 License. University of Rhode Island DigitalCommons@URI PHY 204: Elementary Physics II Physics Course Materials 2015 12. Magnetic Field I Gerhard Müller University of Rhode Island, gmuller@uri.edu Creative Commons

More information

Transmission line demo to illustrate why voltage along transmission lines is high

Transmission line demo to illustrate why voltage along transmission lines is high Transmission line demo to illustrate why voltage along transmission lines is high Connect to step down transformer 120V to 12V to lightbulb 12 V 6.5 A Lights up brightly Connect it to long fat wires Lights

More information

Cyclotron, final. The cyclotron s operation is based on the fact that T is independent of the speed of the particles and of the radius of their path

Cyclotron, final. The cyclotron s operation is based on the fact that T is independent of the speed of the particles and of the radius of their path Cyclotron, final The cyclotron s operation is based on the fact that T is independent of the speed of the particles and of the radius of their path K 1 qbr 2 2m 2 = mv = 2 2 2 When the energy of the ions

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 20 Magnetism

CHAPTER 20 Magnetism CHAPTER 20 Magnetism Units Magnets and Magnetic Fields Electric Currents Produce Magnetic Fields Force on an Electric Current in a Magnetic Field; Definition of B Force on Electric Charge Moving in a Magnetic

More information

Chapter 19. Magnetism

Chapter 19. Magnetism Chapter 19 Magnetism Magnetic Fields When moving through a magnetic field, a charged particle experiences a magnetic force This force has a maximum value when the charge moves perpendicularly to the magnetic

More information

$ B 2 & ) = T

$ B 2 & ) = T Solutions PHYS 251 Final Exam Practice Test 1D If we find the resultant velocity, v, its vector is 13 m/s. This can be plugged into the equation for magnetic force: F = qvb = 1.04 x 10-17 N, where q is

More information

Chapter 27 Magnetic Fields and Magnetic Forces

Chapter 27 Magnetic Fields and Magnetic Forces Chapter 27 Magnetic Fields and Magnetic Forces In this chapter we investigate forces exerted by magnetic fields. In the next chapter we will study the sources of magnetic fields. The force produced by

More information

21 MAGNETIC FORCES AND MAGNETIC FIELDS

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

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, 5:00-6:00 PM Test rooms: Instructor Sections Room Dr. Hale F, H 104 Physics Dr. Kurter, N 125 CH Dr. Madison K, M 199 Toomey Dr. Parris J, L -10 ertelsmeyer* Mr. Upshaw A, C,

More information

General Physics (PHY 2140)

General Physics (PHY 2140) General Physics (PHY 2140) Lecture 8 Electricity and Magnetism 1. Magnetism Application of magnetic forces Ampere s law 2. Induced voltages and induction Magnetic flux http://www.physics.wayne.edu/~alan/2140website/main.htm

More information

Magnetism Chapter Questions

Magnetism Chapter Questions Magnetism Chapter Questions 1. Both Electric and Magnetic Forces will cause objects to repel and attract each other. What is a difference in the origin of these forces? 2. A Magnet has a north and a south

More information

Solve: From Example 33.5, the on-axis magnetic field of a current loop is

Solve: From Example 33.5, the on-axis magnetic field of a current loop is 33.10. Solve: From Example 33.5, the on-axis magnetic field of a current loop is B loop ( z) μ0 = We want to find the value of z such that B( z) B( 0) 0 0 3 = 3 ( z + R ) ( R ) =. 3 R R ( z R ) z R z R(

More information

Magnetism is associated with charges in motion (currents):

Magnetism is associated with charges in motion (currents): Electrics Electromagnetism Electromagnetism Magnetism is associated with charges in motion (currents): microscopic currents in the atoms of magnetic materials. macroscopic currents in the windings of an

More information

Lecture #4.4 Magnetic Field

Lecture #4.4 Magnetic Field Lecture #4.4 Magnetic Field During last several lectures we have been discussing electromagnetic phenomena. However, we only considered examples of electric forces and fields. We first talked about electrostatics

More information

Physics 2212 G Quiz #4 Solutions Spring 2018 = E

Physics 2212 G Quiz #4 Solutions Spring 2018 = E Physics 2212 G Quiz #4 Solutions Spring 2018 I. (16 points) The circuit shown has an emf E, three resistors with resistance, and one resistor with resistance 3. What is the current through the resistor

More information

Lecture 31: MON 30 MAR Review Session : Midterm 3

Lecture 31: MON 30 MAR Review Session : Midterm 3 Physics 2113 Jonathan Dowling Lecture 31: MON 30 MAR Review Session : Midterm 3 EXAM 03: 8PM MON 30 MAR in Cox Auditorium The exam will cover: Ch.26 through Ch.29 The exam will be based on: HW07 HW10.

More information

Electrics. Electromagnetism

Electrics. Electromagnetism Electrics Electromagnetism Electromagnetism Magnetism is associated with charges in motion (currents): microscopic currents in the atoms of magnetic materials. macroscopic currents in the windings of an

More information

Physics Physics 2102

Physics Physics 2102 Physics 2102 Jonathan Dowling Physics 2102 Exam 2: Review Session Chapters 24.9-28.8 / HW04-06 Some links on exam stress: http://appl003.lsu.edu/slas/cas.nsf/$content/stress+management+tip+1 http://wso.williams.edu/orgs/peerh/stress/exams.html

More information

Phys102 Lecture 16/17 Magnetic fields

Phys102 Lecture 16/17 Magnetic fields Phys102 Lecture 16/17 Magnetic fields Key Points Electric Currents Produce Magnetic Fields Force on an Electric Current in a Magnetic Field; Definition of B Force on an Electric Charge Moving in a Magnetic

More information

General Physics II. Magnetism

General Physics II. Magnetism General Physics II Magnetism Bar magnet... two poles: N and S Like poles repel; Unlike poles attract. Bar Magnet Magnetic Field lines [B]: (defined in a similar way as electric field lines, direction and

More information

Exam III Solution: Chapters 18 20

Exam III Solution: Chapters 18 20 PHYS 1420: College Physics II Fall 2006 Exam III Solution: Chapters 18 20 1. The anode of a battery A) has a positive charge, while the cathode has a negative charge. B) has a negative charge, while the

More information

PHY1004W 2010 Electricity and Magnetism Part 3. Prof Andy Buffler Room 503 RW James

PHY1004W 2010 Electricity and Magnetism Part 3. Prof Andy Buffler Room 503 RW James PHY1004W 2010 Electricity and Magnetism Part 3 Prof Andy Buffler Room 503 RW James andy.buffler@uct.ac.za M&I Chapter 19 Capacitors, Resistors and Batteries M&I 19.1 Capacitors in circuits Surface charge

More information

Chapter 7 Magnetism 7.1 Introduction Magnetism has been known thousands of years dating back to the discovery recorded by the ancient Greek.

Chapter 7 Magnetism 7.1 Introduction Magnetism has been known thousands of years dating back to the discovery recorded by the ancient Greek. Chapter 7 Magnetism 7.1 Introduction Magnetism has been known thousands of years dating back to the discovery recorded by the ancient Greek. 1900 Maxwell combine the theory of electric and magnetic to

More information

r r 1 r r 1 2 = q 1 p = qd and it points from the negative charge to the positive charge.

r r 1 r r 1 2 = q 1 p = qd and it points from the negative charge to the positive charge. MP204, Important Equations page 1 Below is a list of important equations that we meet in our study of Electromagnetism in the MP204 module. For your exam, you are expected to understand all of these, and

More information

Chapter 29 The Magnetic Field

Chapter 29 The Magnetic Field Chapter 9 The Magnetic Field y analogy with electrostatics, why don t we study magnetostatics first? Due to complicated mathematics (lack of magnetic monopole). In 80, Oersted established the link between

More information

Chapter 24: Magnetic Fields & Forces

Chapter 24: Magnetic Fields & Forces Chapter 24: Magnetic Fields & Forces We live in a magnetic field. The earth behaves almost as if a bar magnet were located near its center. The earth s axis of rotation and Magnetic axis are not the same

More information

Magnetic Fields. David J. Starling Penn State Hazleton PHYS 212

Magnetic Fields. David J. Starling Penn State Hazleton PHYS 212 Magnetism, as you recall from physics class, is a powerful force that causes certain items to be attracted to refrigerators. - Dave Barry David J. Starling Penn State Hazleton PHYS 212 is responsible for

More information

m e = m/s. x = vt = t = x v = m

m e = m/s. x = vt = t = x v = m 5. (a) The textbook uses geomagnetic north to refer to Earth s magnetic pole lying in the northern hemisphere. Thus, the electrons are traveling northward. The vertical component of the magnetic field

More information

Physics Tutorial MF1 Magnetic Forces

Physics Tutorial MF1 Magnetic Forces Physics Tutorial MF1 Magnetic Forces 1 Magnetic Forces The force F on a charge q moving with velocity v in a magnetic field is: F = qv The force F on a straight conductor of length L carrying a current

More information

Torque on a Current Loop

Torque on a Current Loop Today Chapter 19 Magnetism Torque on a current loop, electrical motor Magnetic field around a current carrying wire. Ampere s law Solenoid Material magnetism Clicker 1 Which of the following is wrong?

More information

PHY132 Lecture 13 02/24/2010. Lecture 13 1

PHY132 Lecture 13 02/24/2010. Lecture 13 1 Classical Physics II PHY132 Lecture 13 Magnetism II: Magnetic torque Lecture 13 1 Magnetic Force MAGNETISM is yet another force that has been known since a very long time. Its name stems from the mineral

More information

4. An electron moving in the positive x direction experiences a magnetic force in the positive z direction. If B x

4. An electron moving in the positive x direction experiences a magnetic force in the positive z direction. If B x Magnetic Fields 3. A particle (q = 4.0 µc, m = 5.0 mg) moves in a uniform magnetic field with a velocity having a magnitude of 2.0 km/s and a direction that is 50 away from that of the magnetic field.

More information

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

Agenda for Today. Elements of Physics II. Forces on currents Forces on currents Physics 132: Lecture e 20 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

More information

11/21/2011. The Magnetic Field. Chapter 24 Magnetic Fields and Forces. Mapping Out the Magnetic Field Using Iron Filings

11/21/2011. The Magnetic Field. Chapter 24 Magnetic Fields and Forces. Mapping Out the Magnetic Field Using Iron Filings Chapter 24 Magnetic Fields and Forces Topics: Magnets and the magnetic field Electric currents create magnetic fields Magnetic fields of wires, loops, and solenoids Magnetic forces on charges and currents

More information

Figure 1 A) 2.3 V B) +2.3 V C) +3.6 V D) 1.1 V E) +1.1 V Q2. The current in the 12- Ω resistor shown in the circuit of Figure 2 is:

Figure 1 A) 2.3 V B) +2.3 V C) +3.6 V D) 1.1 V E) +1.1 V Q2. The current in the 12- Ω resistor shown in the circuit of Figure 2 is: Term: 13 Wednesday, May 1, 014 Page: 1 Q1. What is the potential difference V B -V A in the circuit shown in Figure 1 if R 1 =70.0 Ω, R=105 Ω, R 3 =140 Ω, ε 1 =.0 V and ε =7.0 V? Figure 1 A).3 V B) +.3

More information

MAGNETIC EFFECTS OF CURRENT AND MAGNETISM

MAGNETIC EFFECTS OF CURRENT AND MAGNETISM UNIT III MAGNETIC EFFECTS OF CURRENT AND MAGNETISM Weightage 8 Marks Concept of magnetic field and Oersted s experiment Biot-savart law and its application to current carrying circular loop. Ampere s law

More information

Solutions to PHY2049 Exam 2 (Nov. 3, 2017)

Solutions to PHY2049 Exam 2 (Nov. 3, 2017) Solutions to PHY2049 Exam 2 (Nov. 3, 207) Problem : In figure a, both batteries have emf E =.2 V and the external resistance R is a variable resistor. Figure b gives the electric potentials V between the

More information

PHY Fall HW6 Solutions

PHY Fall HW6 Solutions PHY249 - Fall 216 - HW6 Solutions Allen Majewski Department Of Physics, University of Florida 21 Museum Rd. Gainesville, FL 32611 October 11, 216 These are solutions to Halliday, Resnick, Walker Chapter

More information

PHYS Fields and Waves

PHYS Fields and Waves PHYS 2421 - Fields and Waves Idea: We have seen: currents can produce fields We will now see: fields can produce currents Facts: Current is produced in closed loops when the magnetic flux changes Notice:

More information

Lecture 13. Magnetic Field, Magnetic Forces on Moving Charges.

Lecture 13. Magnetic Field, Magnetic Forces on Moving Charges. Lecture 13. Magnetic Field, Magnetic Forces on Moving Charges. What are magnetic forces? Forces between magnets Forces between magnets and magnetizable materials Forces between magnets and moving charges

More information

Electricity and Magnetism Charges in Crossed E- and B-Fields

Electricity and Magnetism Charges in Crossed E- and B-Fields Electricit and Magnetism Charges in Crossed E- and B-Fields Lana Sheridan De Anza College Nov 4, 2015 Last time magnetic force on a charge circular trajectories helical trajectories CHECKPOINT 2 Warm Up

More information

Physics 8.02 Exam Two Equation Sheet Spring 2004

Physics 8.02 Exam Two Equation Sheet Spring 2004 Physics 8.0 Exam Two Equation Sheet Spring 004 closed surface EdA Q inside da points from inside o to outside I dsrˆ db 4o r rˆ points from source to observer V moving from a to b E ds 0 V b V a b E ds

More information

Physics H. Instructor: Dr. Alaa Mahmoud

Physics H. Instructor: Dr. Alaa Mahmoud Physics 202 1436-1437 H Instructor: Dr. Alaa Mahmoud E-mail: alaa_y_emam@hotmail.com Chapter 28 magnetic Field Magnetic fingerprinting allows fingerprints to be seen on surfaces that otherwise would not

More information

PHYS ND semester Dr. Nadyah Alanazi. Lecture 16

PHYS ND semester Dr. Nadyah Alanazi. Lecture 16 1 PHYS 104 2 ND semester 1439-1440 Dr. Nadyah Alanazi Lecture 16 2 Chapter 29 Magnetic Field 29.1 Magnetic Fields and Forces 29.2 Magnetic Force Acting on a Current-Carrying Conductor 29.4 Motion of a

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 102: Magnetic Fields

Physics 102: Magnetic Fields Physics 102: Magnetic Fields Assist. Prof. Dr. Ali Övgün EMU Physics Department www.aovgun.com Electric Field & Magnetic Field Electric forces acting at a distance through electric field. Vector field,

More information

Ch. 28: Sources of Magnetic Fields

Ch. 28: Sources of Magnetic Fields Ch. 28: Sources of Magnetic Fields Electric Currents Create Magnetic Fields A long, straight wire A current loop A solenoid Slide 24-14 Biot-Savart Law Current produces a magnetic field The Biot-Savart

More information

Homework due tonight 11:59 PM Office hour today a;er class (3-4PM) in Serin nd floor tea room

Homework due tonight 11:59 PM Office hour today a;er class (3-4PM) in Serin nd floor tea room Homework due tonight 11:59 PM Office hour today a;er class (3-4PM) in Serin 287 2 nd floor tea room SUNDAY Nov 18: SECOND HOUR EXAM 6:10-7:30 PM in SEC 111 (Ch. 26-30) -- no recitauons the previous Friday

More information

Chapter 4: Magnetic Field

Chapter 4: Magnetic Field Chapter 4: Magnetic Field 4.1 Magnetic Field 4.1.1 Define magnetic field Magnetic field is defined as the region around a magnet where a magnetic force can be experienced. Magnetic field has two poles,

More information