PHYS 155: Final Tutorial

Save this PDF as:
 WORD  PNG  TXT  JPG

Size: px
Start display at page:

Download "PHYS 155: Final Tutorial"

Transcription

1 Final Tutorial Saskatoon Engineering Students Society April 13, 2015

2 Overview

3 Tutorial Slides These slides have been posted: sess.usask.ca homepage.usask.ca/esp991/

4 Section 1

5 have no start, no finish. There is NO point of origin. They are created by movement of charge. B = 0 B = µ 0 J + µ 0 E 0 de dt Changing fields can incite EMF in other objects. E = db dt

6 Field Lines Field lines have no start, no finish. field strength B related to density of field lines.

7 Three Very Spatial Assume Positive Charge and Current Find magnetic field direction in various cases Find force on a moving charge or current carrying wire.

8 RHR 1: Field Around a field circles around wires, in a direction CCW when wire is coming out of page. Put your thumb along wire. Your fingers curl around wire along magnetic field lines.

9 RHR 2: Field Inside a loop or Coil of wound in a coil generates a magnetic field directed along the axis of the coil. Fingers wrap around the loop or coil, in the direction of the current. Thumb points in the direction of magnetic field.

10 RHR 2: Additional Consideration We can find RHR No. 2 by applying Rule No. 1 to a coil instead of a straight wire!

11 RHR 3: Force on a Moving Charge Charge or current moving in a magnetic field experiences a magnetic force. Perpendicular to direction of movement Perpendicular to magnetic field.

12 RHR 3: Force on a Moving Charge Thumb Along Direction of Movement Index Finger along Field Palm / middle finger points to the force! Remember, this is for POSITIVE Charge. For negative charge like electrons, the force is opposite!

13 RHR 3: Force on a Moving Charge

14 : RHR #1: Straight Thumb Along Direction of Current Fingers curl the way the magnetic field does. RHR #2: Coil / Loop of Curl fingers around coil of wire in direction of current Thumb tells you direction of magnetic field RHR #3: Charge Moving in Field Thumb Along Movement of Positive Charge Index finger along magnetic field direction Palm or middle finger tells you direction of force on positive charge.

15 Some Helpful Formulas Field for a long, straight wire Field at Centre of Loop Field Inside Solenoid B = µ 0I 2πr B = N µ 0I 2R B = µ o ni = µ 0 N l I Force on Moving Charge / in Field F = q(v B) F = qvb sin θ

16 Example 1 Lorentz Force A proton moving at m/s through a magnetic field of magnitude 1.70 T experiences a magnetic force of magnitude N. What is the angle between the proton s velocity and the field?

17 Example 1 Solution Draw a picture showing this effect. Lorentz force is so F = q v B F = qvb sin θ Using magnitude of force, velocity and magnetic field, solve for θ. Answer: θ = or

18 Example 2 Cyclotron Motion A singly charged ion of mass m is accelerated from rest by a potential difference V. It is then deflected by a uniform magnetic field (perpendicular to the ion s velocity) into a semicircle of radius R. Now a doubly charged ion of mass m is accelerated through the same potential difference and deflected by the same magnetic field into a semicircle of radius R = 2R. What is the ratio of the masses of the ions?

19 Example 2 Solution Write the kinetic energy of the particle. KE = q V = 1 2 mv 2 (1) Write the conditition for centripetal acceleration F m = F c, qvb = mv 2 R (2)

20 Example 2 Solution Sub (1) into (2) and solve for m in terms of q, B, V and R. m = B2 2 V qr2 Solve for m in terms of q, B, V and R. Note that all you have to do is tweak your q, B & R values. Answer: m = 8.00 m. m = B2 2 V (2q)(2R)2

21 Example 3 Hold Straight Condition A velocity selector consists of electric and magnetic fields described by the expressions E = E ˆk and B = Bĵ, with B = 15.0mT. Find the value of E such that a 750-eV electron moving in the negative x direction is undeflected.

22 Example 3 Solution Draw your picture. Which way will the magnetic field try to direct the electron? (Up) Which way does the electric force need to apply? (Down). Which way should the field be pointed? (Up) Solve for electron velocity using K E = 1 2 mv 2 Draw FBD and write the condition for no deflection: F M + F E = 0

23 Example 3 Solution Figure out the magnitude of the magnetic force on the electron. Note that Solve for E. Answer: 244 kv/m F M = q v B = ˆk N F E = E ˆk = F M

24 Break See you in 10 Minutes

25 Section 4 Torque on due to Field

26 Force on a Extension of RHR #3. F = I ( l B) F = I lb sin θ l is length of wire, whose direction is the direction of the current. For 2 parallel wires, the force of attraction/repulsion is F = µ 0 I 1 I 2 2π d L Attraction if current in same direction Repulsion if current in opposite direction

27 Torque on a Loop A loop of wire in a magnetic field expriences a torque, according to τ = NI [ A B] τ = NIAB sin θ the A vector has magnitude equal to area of loop, direction points in direction of magnetic field generated by loop (use RHR 2).

28 Example 4 Torque on A current of 17.0mA is maintained in a single circular loop of 2.00 m circumference. A magnetic field of T is directed parallel to the plane of the loop. What is the torque exerted on the loop by the magnetic field?

29 Example 4 Solution 1 Draw a picture of the loop of wire and the field. Conceptualize: if current flows in the loop, and the magnetic field is parallel to the plane of the loop, which side will try to lift up? Which side will be pushed down? 2 Solve for area of the loop using circumference. 3 Use Torque Formula to solve for torque. Answer: N m. τ = NI [ A B]

30 Example 5 Attraction Between s The current in the long, straight wire is I 1 = 5.00 A and the wire lies in the plane of the rectangular loop, which carries a current I 2 = 10.0 A. The dimensions in the figure are c =0.100 m, a = m, and l = m. Find the magnitude and direction of the net force exerted on the loop by the magnetic field created by the wire.

31 Example 5 Solution 1 Ask yourself: Which way will each part of the loop try to move? 2 Find the strength of the magnetic field due to the long wire at the left side of the loop. B = µ 0I 1 2πc 3 Find the Lorentz force on the left side of the loop F = I 2 l B 4 Find the magnetic field strength and the force on the right side of the loop. B = µ 0 I 1 2π(c + a) F = I 2 l B

32 Example 5 Solution Note that the top and bottom parts of the loop experience forces too, but they cancel out. Subtract the force of the right side of the loop from the force of the left side of the loop to find net force. Answer: î N

33 Section 5

34 Let s us find the magnetic field around an enclosed loop of wire. Comes from B = µ 0 J + µ 0 E 0 de dt This simplifies to B dl = µ0 I enc. Pick some sort of symmetry, usually circular, around some source of current. Then you can find the magnetic field strength.

35 Example 6 A packed bundle of 100 long, straight, insulated wires forms a cylinder of radius R = cm. If each wire carries 2.00 A, what are the (a) magnitude and (b) direction of the magnetic force per unit length acting on a wire located cm from the centre of the bundle?

36 Example 6 Solution 1 Recall : B dl = µ 0 I enc 2 Figure out the current enclosed by a radius of 0.2cm. (It s 32 amps). 3 If we integrate around a circle, centred at the centre of the wire, B will be constant because of radial symmetry. So you get 4 Solve for B B (2πr) = µ 0 I enc 5 Multiply by 2A, the current of 1 wire at that radius. (F/l=IB) Answer: F/l = 6.4 mn.

37 Break See you in 10 Minutes

38 Section 7 and Lenz s Law

39 Lenz s Law A loop or coil of wire that is exposed to a change in magnetic flux through the loop will induce an EMF whose corresponding magnetic field will oppose the original change in flux.

40 Mathematical Representation of Lenz s Law E = N dφ dt = N d (AB cos θ) dt So we get Back EMF for one of three reasons: Change in Area, Field Strength or Angle. Usually only one will change at a time in any given question.

41 Example 7 Faraday Law A coil formed by wrapping 50 turns of wire in the shape of a square is positioned in a magnetic field so that the normal to the plane of the coil makes an angle of 30.0 with the direction of the field. When the magnetic field is increased uniformly from 200 µt to 600 µt in s, an emf of magnitude 80.0 mv is induced in the coil. What is the total length of the wire in the coil?

42 Example 7 Solution 1 Recall Faraday Law E = N dφ dt = N d (AB cos θ) dt 2 Here, only the magnetic field is changing, so this simplifies to E = NA db dt cos θ 3 Solve for A, then find side length, then multiply by 4N to get length of wire. Answer: 272m.

43 Bar and Rail Problems 1 Figure out the induced EMF Lenz s Law to find direction. for magnitude. 2 Using EMF, find current in loop (Ohm s Law, KVL) 3 Using I and Lorentz force law, find magnetic force on bar. 4 Draw FBD of Bar, solve unknowns. Find any input force required. 5 Watch out for directions of B, v and F, especially on angled rails!

44 Example 8 Bar and Rail The picture shows a bar of mass m = kg that can slide without friction on a pair of rails separated by a distance ` = 1.20 m and located on an inclined plane that makes an angle θ = 25.0 with respect to the horizontal. The resistance of the resistor is R = 1.00 Ω and a uniform magnetic field of magnitude B = T is directed downward, perpendicular to the ground, over the entire region through which the bar moves. With what constant speed v does the bar slide along the rails?

45 Example 8 Solution 1 Solve for EMF using E = lvb cos θ 2 Use Ohm s Law to find current through loop. I = E/R 3 Lorenz Force Law (F = qvb) to find the back EMF force on the bar (* Watch out for direction here *). 4 Draw FBD to find relation between F M, N and F g. 5 For constant velocity, you can relate F M and F g. Solve for v Answer: 2.80 m/s v = mg tan θr l 2 B 2 cos θ

46 Section 8

47 Self E = N dφ dt Mutual E L = L di dt L = µ 0 N 2 l A = µ 0µ r N 2 A l Energy In an Inductor N s Φ s = MI P U = 1 2 LI 2 E s = M di P dt

48 Example 9 Mutual Two solenoids A and B, spaced close to each other and sharing the same cylindrical axis, have 400 and 700 turns respectively. A current of 3.50 A in solenoid A produces an average flux of 300 µwb through each turn of A and a flux of 90.0 µwb through each turn of B. (a) Calculate the mutual inductance of the two solenoids. (b) What is the inductance of A? (c) What emf is induced in B when the current in A changes at a rate of 0.5 A/s?

49 Example 9 Solution 1 Use the mutual inductance formula that has all the variables you know. N S Φ S = MI P 2 To find self inductance, use self inductance formula relating flux and current. NΦ = LI 3 To find EMF, use EMF formula with mutual inductance. E S = M di P dt

50 Example 9 Solution It might be helpful to pay attention to the directions of the coils here. Remember that the - serves to remind you that it is back EMF, but the winding of the coil actually decides the direction of current. Answer: H, H, -9mV.

51 Transformers Just remeber the transformer turn ratio formula, relating current, voltage and number of turns in the Primary and Secondary coils. N P N S = V P V S = I S I P Use Ohm s Law and P = VI to solve for everything else.

52 Example 10 Transformers In the transformer shown, the load resistance R L is 50.0 Ω. The turns ratio N 1 /N 2 is 2.50, and the rms source voltage is V s = 80.0 V. If a voltmeter across the load resistance measures an rms voltage of 25.0 V, what is the source resistance R s?

53 Example 10 Solution Remember the big important transformer equation. N P N S = V P V S = I S I P Using the secondary coil voltage and Ohm s law, find current in secondary coil. Using turns ratio, find the current in primary coil and voltage in primary across the transformer. KVL to find voltage across resistor, and Ohm s Law to find resistance. Answer: 87.5 Ω

54 1 Go through the slides (both mine and the ones on blackboard) and make up a solid formula sheet. 2 Have a good section on unit conversions, and what units you can expect from certain formulas. 3 Do the assignments. Each question has a recipe to solve it. Practise your Lenz Law to anticipate direction of magnetic fields and back EMF. 4 Watch out for weird units on the exam.

55 Good Luck! These slides have been posted: sess.usask.ca homepage.usask.ca/esp991/

Solution: (a) For a positively charged particle, the direction of the force is that predicted by the right hand rule. These are:

Solution: (a) For a positively charged particle, the direction of the force is that predicted by the right hand rule. These are: Problem 1. (a) Find the direction of the force on a proton (a positively charged particle) moving through the magnetic fields as shown in the figure. (b) Repeat part (a), assuming the moving particle is

More information

Homework #8 203-1-1721 Physics 2 for Students of Mechanical Engineering. Part A

Homework #8 203-1-1721 Physics 2 for Students of Mechanical Engineering. Part A Homework #8 203-1-1721 Physics 2 for Students of Mechanical Engineering Part A 1. Four particles follow the paths shown in Fig. 32-33 below as they pass through the magnetic field there. What can one conclude

More information

Exam 2 Solutions. PHY2054 Spring Prof. P. Kumar Prof. P. Avery March 5, 2008

Exam 2 Solutions. PHY2054 Spring Prof. P. Kumar Prof. P. Avery March 5, 2008 Prof. P. Kumar Prof. P. Avery March 5, 008 Exam Solutions 1. Two cylindrical resistors are made of the same material and have the same resistance. The resistors, R 1 and R, have different radii, r 1 and

More information

Chapter 22 Magnetism

Chapter 22 Magnetism 22.6 Electric Current, Magnetic Fields, and Ampere s Law Chapter 22 Magnetism 22.1 The Magnetic Field 22.2 The Magnetic Force on Moving Charges 22.3 The Motion of Charged particles in a Magnetic Field

More information

Conceptual: 1, 3, 5, 6, 8, 16, 18, 19. Problems: 4, 6, 8, 11, 16, 20, 23, 27, 34, 41, 45, 56, 60, 65. Conceptual Questions

Conceptual: 1, 3, 5, 6, 8, 16, 18, 19. Problems: 4, 6, 8, 11, 16, 20, 23, 27, 34, 41, 45, 56, 60, 65. Conceptual Questions Conceptual: 1, 3, 5, 6, 8, 16, 18, 19 Problems: 4, 6, 8, 11, 16, 20, 23, 27, 34, 41, 45, 56, 60, 65 Conceptual Questions 1. The magnetic field cannot be described as the magnetic force per unit charge

More information

Phys222 Winter 2012 Quiz 4 Chapters 29-31. Name

Phys222 Winter 2012 Quiz 4 Chapters 29-31. Name Name If you think that no correct answer is provided, give your answer, state your reasoning briefly; append additional sheet of paper if necessary. 1. A particle (q = 5.0 nc, m = 3.0 µg) moves in a region

More information

Physics 121 Sample Common Exam 3 NOTE: ANSWERS ARE ON PAGE 6. Instructions: 1. In the formula F = qvxb:

Physics 121 Sample Common Exam 3 NOTE: ANSWERS ARE ON PAGE 6. Instructions: 1. In the formula F = qvxb: Physics 121 Sample Common Exam 3 NOTE: ANSWERS ARE ON PAGE 6 Signature Name (Print): 4 Digit ID: Section: Instructions: Answer all questions 24 multiple choice questions. You may need to do some calculation.

More information

Physics 126 Practice Exam #3 Professor Siegel

Physics 126 Practice Exam #3 Professor Siegel Physics 126 Practice Exam #3 Professor Siegel Name: Lab Day: 1. Which one of the following statements concerning the magnetic force on a charged particle in a magnetic field is true? A) The magnetic force

More information

Physics 2220 Module 09 Homework

Physics 2220 Module 09 Homework Physics 2220 Module 09 Homework 01. A potential difference of 0.050 V is developed across the 10-cm-long wire of the figure as it moves though a magnetic field perpendicular to the page. What are the strength

More information

VIII. Magnetic Fields - Worked Examples

VIII. Magnetic Fields - Worked Examples MASSACHUSETTS INSTITUTE OF TECHNOLOGY Department of Physics 8.0 Spring 003 VIII. Magnetic Fields - Worked Examples Example : Rolling rod A rod with a mass m and a radius R is mounted on two parallel rails

More information

Physics 112 Homework 5 (solutions) (2004 Fall) Solutions to Homework Questions 5

Physics 112 Homework 5 (solutions) (2004 Fall) Solutions to Homework Questions 5 Solutions to Homework Questions 5 Chapt19, Problem-2: (a) Find the direction of the force on a proton (a positively charged particle) moving through the magnetic fields in Figure P19.2, as shown. (b) Repeat

More information

Fall 12 PHY 122 Homework Solutions #8

Fall 12 PHY 122 Homework Solutions #8 Fall 12 PHY 122 Homework Solutions #8 Chapter 27 Problem 22 An electron moves with velocity v= (7.0i - 6.0j)10 4 m/s in a magnetic field B= (-0.80i + 0.60j)T. Determine the magnitude and direction of the

More information

Magnetism. d. gives the direction of the force on a charge moving in a magnetic field. b. results in negative charges moving. clockwise.

Magnetism. d. gives the direction of the force on a charge moving in a magnetic field. b. results in negative charges moving. clockwise. Magnetism 1. An electron which moves with a speed of 3.0 10 4 m/s parallel to a uniform magnetic field of 0.40 T experiences a force of what magnitude? (e = 1.6 10 19 C) a. 4.8 10 14 N c. 2.2 10 24 N b.

More information

Chapter 19: Magnetic Forces and Fields

Chapter 19: Magnetic Forces and Fields Chapter 19: Magnetic Forces and Fields Magnetic Fields Magnetic Force on a Point Charge Motion of a Charged Particle in a Magnetic Field Crossed E and B fields Magnetic Forces on Current Carrying Wires

More information

) 0.7 =1.58 10 2 N m.

) 0.7 =1.58 10 2 N m. Exam 2 Solutions Prof. Paul Avery Prof. Andrey Korytov Oct. 29, 2014 1. A loop of wire carrying a current of 2.0 A is in the shape of a right triangle with two equal sides, each with length L = 15 cm as

More information

Induced voltages and Inductance Faraday s Law

Induced voltages and Inductance Faraday s Law Induced voltages and Inductance Faraday s Law concept #1, 4, 5, 8, 13 Problem # 1, 3, 4, 5, 6, 9, 10, 13, 15, 24, 23, 25, 31, 32a, 34, 37, 41, 43, 51, 61 Last chapter we saw that a current produces a magnetic

More information

Chapter 30 - Magnetic Fields and Torque. A PowerPoint Presentation by Paul E. Tippens, Professor of Physics Southern Polytechnic State University

Chapter 30 - Magnetic Fields and Torque. A PowerPoint Presentation by Paul E. Tippens, Professor of Physics Southern Polytechnic State University Chapter 30 - Magnetic Fields and Torque A PowerPoint Presentation by Paul E. Tippens, Professor of Physics Southern Polytechnic State University 2007 Objectives: After completing this module, you should

More information

My lecture slides are posted at Information for Physics 112 midterm, Wednesday, May 2

My lecture slides are posted at  Information for Physics 112 midterm, Wednesday, May 2 My lecture slides are posted at http://www.physics.ohio-state.edu/~humanic/ Information for Physics 112 midterm, Wednesday, May 2 1) Format: 10 multiple choice questions (each worth 5 points) and two show-work

More information

Force on Moving Charges in a Magnetic Field

Force on Moving Charges in a Magnetic Field [ Assignment View ] [ Eðlisfræði 2, vor 2007 27. Magnetic Field and Magnetic Forces Assignment is due at 2:00am on Wednesday, February 28, 2007 Credit for problems submitted late will decrease to 0% after

More information

1) Magnetic field lines come out of the south pole of a magnet and enter at the north pole.

1) Magnetic field lines come out of the south pole of a magnet and enter at the north pole. Exam Name 1) Magnetic field lines come out of the south pole of a magnet and enter at the north pole. 2) Which of the following statements is correct? A) Earth's north pole is magnetic north. B) The north

More information

AP2 Magnetism. (c) Explain why the magnetic field does no work on the particle as it moves in its circular path.

AP2 Magnetism. (c) Explain why the magnetic field does no work on the particle as it moves in its circular path. A charged particle is projected from point P with velocity v at a right angle to a uniform magnetic field directed out of the plane of the page as shown. The particle moves along a circle of radius R.

More information

Physics 9 Fall 2009 Homework 7 - Solutions

Physics 9 Fall 2009 Homework 7 - Solutions Physics 9 Fall 009 Homework 7 - s 1. Chapter 33 - Exercise 10. At what distance on the axis of a current loop is the magnetic field half the strength of the field at the center of the loop? Give your answer

More information

Physics 1653 Exam 3 - Review Questions

Physics 1653 Exam 3 - Review Questions Physics 1653 Exam 3 - Review Questions 3.0 Two uncharged conducting spheres, A and B, are suspended from insulating threads so that they touch each other. While a negatively charged rod is held near, but

More information

Physics 2212 GH Quiz #4 Solutions Spring 2015

Physics 2212 GH Quiz #4 Solutions Spring 2015 Physics 1 GH Quiz #4 Solutions Spring 15 Fundamental Charge e = 1.6 1 19 C Mass of an Electron m e = 9.19 1 31 kg Coulomb constant K = 8.988 1 9 N m /C Vacuum Permittivity ϵ = 8.854 1 1 C /N m Earth s

More information

Question Details C14: Magnetic Field Direction Abbott [ ]

Question Details C14: Magnetic Field Direction Abbott [ ] Phys 1114: Assignment 9 Abbott (5420633) Due: Mon Apr 7 2014 11:59 PM CDT Question 1 2 3 4 5 6 7 8 9 10 11 1. Question Details C14: Magnetic Field Direction Abbott [2861537] a) A wire is oriented horizontally

More information

PH 212 07-31-2015 Physics 212 Exam-3 Solution NAME: Write down your name also on the back of the package of sheets you turn in.

PH 212 07-31-2015 Physics 212 Exam-3 Solution NAME: Write down your name also on the back of the package of sheets you turn in. PH 1 7-31-15 Physics 1 Exam-3 Solution NAME: Write down your name also on the back of the package of sheets you turn in. SIGNATURE and ID: Return this hard copy exam together with your other answer sheets.

More information

Chapter 14 Magnets and

Chapter 14 Magnets and Chapter 14 Magnets and Electromagnetism How do magnets work? What is the Earth s magnetic field? Is the magnetic force similar to the electrostatic force? Magnets and the Magnetic Force! We are generally

More information

ElectroMagnetic Induction. AP Physics B

ElectroMagnetic Induction. AP Physics B ElectroMagnetic Induction AP Physics B 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

More information

1. Units of a magnetic field might be: A. C m/s B. C s/m C. C/kg D. kg/c s E. N/C m ans: D

1. Units of a magnetic field might be: A. C m/s B. C s/m C. C/kg D. kg/c s E. N/C m ans: D Chapter 28: MAGNETIC FIELDS 1 Units of a magnetic field might be: A C m/s B C s/m C C/kg D kg/c s E N/C m 2 In the formula F = q v B: A F must be perpendicular to v but not necessarily to B B F must be

More information

Chapter 19 Magnetic Forces and Fields

Chapter 19 Magnetic Forces and Fields Chapter 19 Magnetic Forces and Fields Student: 3. The magnetism of the Earth acts approximately as if it originates from a huge bar magnet within the Earth. Which of the following statements are true?

More information

Solution Derivations for Capa #11

Solution Derivations for Capa #11 Solution Derivations for Capa #11 Caution: The symbol E is used interchangeably for energy and EMF. 1) DATA: V b = 5.0 V, = 155 Ω, L = 8.400 10 2 H. In the diagram above, what is the voltage across the

More information

Magnetic Fields and Forces. AP Physics B

Magnetic Fields and Forces. AP Physics B Magnetic ields and orces AP Physics acts about Magnetism Magnets have 2 poles (north and south) Like poles repel Unlike poles attract Magnets create a MAGNETIC IELD around them Magnetic ield A bar magnet

More information

45. The peak value of an alternating current in a 1500-W device is 5.4 A. What is the rms voltage across?

45. The peak value of an alternating current in a 1500-W device is 5.4 A. What is the rms voltage across? PHYS Practice Problems hapters 8- hapter 8. 45. The peak value of an alternating current in a 5-W device is 5.4 A. What is the rms voltage across? The power and current can be used to find the peak voltage,

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

Physics 30 Worksheet #10 : Magnetism From Electricity

Physics 30 Worksheet #10 : Magnetism From Electricity Physics 30 Worksheet #10 : Magnetism From Electricity 1. Draw the magnetic field surrounding the wire showing electron current below. x 2. Draw the magnetic field surrounding the wire showing electron

More information

CHARGED PARTICLES & MAGNETIC FIELDS - WebAssign

CHARGED PARTICLES & MAGNETIC FIELDS - WebAssign Name: Period: Due Date: Lab Partners: CHARGED PARTICLES & MAGNETIC FIELDS - WebAssign Purpose: Use the CP program from Vernier to simulate the motion of charged particles in Magnetic and Electric Fields

More information

CHARGE TO MASS RATIO OF THE ELECTRON

CHARGE TO MASS RATIO OF THE ELECTRON CHARGE TO MASS RATIO OF THE ELECTRON In solving many physics problems, it is necessary to use the value of one or more physical constants. Examples are the velocity of light, c, and mass of the electron,

More information

1. The diagram below represents magnetic lines of force within a region of space.

1. The diagram below represents magnetic lines of force within a region of space. 1. The diagram below represents magnetic lines of force within a region of space. 4. In which diagram below is the magnetic flux density at point P greatest? (1) (3) (2) (4) The magnetic field is strongest

More information

Module 3 : Electromagnetism Lecture 13 : Magnetic Field

Module 3 : Electromagnetism Lecture 13 : Magnetic Field Module 3 : Electromagnetism Lecture 13 : Magnetic Field Objectives In this lecture you will learn the following Electric current is the source of magnetic field. When a charged particle is placed in an

More information

Review Questions PHYS 2426 Exam 2

Review Questions PHYS 2426 Exam 2 Review Questions PHYS 2426 Exam 2 1. If 4.7 x 10 16 electrons pass a particular point in a wire every second, what is the current in the wire? A) 4.7 ma B) 7.5 A C) 2.9 A D) 7.5 ma E) 0.29 A Ans: D 2.

More information

Direction of Induced Current

Direction of Induced Current Direction of Induced Current Bar magnet moves through coil Current induced in coil A S N v Reverse pole Induced current changes sign B N S v v Coil moves past fixed bar magnet Current induced in coil as

More information

Chapter 27 Magnetic Field and Magnetic Forces

Chapter 27 Magnetic Field and Magnetic Forces Chapter 27 Magnetic Field and Magnetic Forces - Magnetism - Magnetic Field - Magnetic Field Lines and Magnetic Flux - Motion of Charged Particles in a Magnetic Field - Applications of Motion of Charged

More information

CET Moving Charges & Magnetism

CET Moving Charges & Magnetism CET 2014 Moving Charges & Magnetism 1. When a charged particle moves perpendicular to the direction of uniform magnetic field its a) energy changes. b) momentum changes. c) both energy and momentum

More information

Physics 2B. Lecture 29B

Physics 2B. Lecture 29B Physics 2B Lecture 29B "There is a magnet in your heart that will attract true friends. That magnet is unselfishness, thinking of others first. When you learn to live for others, they will live for you."

More information

Profs. A. Petkova, A. Rinzler, S. Hershfield. Exam 2 Solution

Profs. A. Petkova, A. Rinzler, S. Hershfield. Exam 2 Solution PHY2049 Fall 2009 Profs. A. Petkova, A. Rinzler, S. Hershfield Exam 2 Solution 1. Three capacitor networks labeled A, B & C are shown in the figure with the individual capacitor values labeled (all units

More information

Exam 1 Practice Problems Solutions

Exam 1 Practice Problems Solutions MASSACHUSETTS INSTITUTE OF TECHNOLOGY Department of Physics 8 Spring 13 Exam 1 Practice Problems Solutions Part I: Short Questions and Concept Questions Problem 1: Spark Plug Pictured at right is a typical

More information

Physics 9 Fall 2009 Homework 8 - Solutions

Physics 9 Fall 2009 Homework 8 - Solutions 1. Chapter 34 - Exercise 9. Physics 9 Fall 2009 Homework 8 - s The current in the solenoid in the figure is increasing. The solenoid is surrounded by a conducting loop. Is there a current in the loop?

More information

104 Practice Exam 2-3/21/02

104 Practice Exam 2-3/21/02 104 Practice Exam 2-3/21/02 1. Two electrons are located in a region of space where the magnetic field is zero. Electron A is at rest; and electron B is moving westward with a constant velocity. A non-zero

More information

Chapter 24 Practice Problems, Review, and Assessment

Chapter 24 Practice Problems, Review, and Assessment Section 1 Understanding Magnetism: Practice Problems 1. If you hold a bar magnet in each hand and bring your hands close together, will the force be attractive or repulsive if the magnets are held in the

More information

TIME OF COMPLETION DEPARTMENT OF NATURAL SCIENCES. PHYS 2212, Exam 2 Section 1 Version 1 April 16, 2014 Total Weight: 100 points

TIME OF COMPLETION DEPARTMENT OF NATURAL SCIENCES. PHYS 2212, Exam 2 Section 1 Version 1 April 16, 2014 Total Weight: 100 points TIME OF COMPLETION NAME DEPARTMENT OF NATURAL SCIENCES PHYS 2212, Exam 2 Section 1 Version 1 April 16, 2014 Total Weight: 100 points 1. Check your examination for completeness prior to starting. There

More information

Chapter 20. Magnetic Induction Changing Magnetic Fields yield Changing Electric Fields

Chapter 20. Magnetic Induction Changing Magnetic Fields yield Changing Electric Fields Chapter 20 Magnetic Induction Changing Magnetic Fields yield Changing Electric Fields Introduction The motion of a magnet can induce current in practical ways. If a credit card has a magnet strip on its

More information

The purposes of this experiment are to test Faraday's Law qualitatively and to test Lenz's Law.

The purposes of this experiment are to test Faraday's Law qualitatively and to test Lenz's Law. 260 17-1 I. THEORY EXPERIMENT 17 QUALITATIVE STUDY OF INDUCED EMF Along the extended central axis of a bar magnet, the magnetic field vector B r, on the side nearer the North pole, points away from this

More information

electron due to the magnetic field. (b) Repeat your calculation for a proton having the same velocity.

electron due to the magnetic field. (b) Repeat your calculation for a proton having the same velocity. PROBLEMS sec. 28-3 The Definition of 1 A proton traveling at 23.0 with respect to the direction of a magnetic field of strength 2.60 mt experiences a magnetic force of 6.50 10-17 N. Calculate (a) the proton's

More information

Magnetic Field of a Circular Coil Lab 12

Magnetic Field of a Circular Coil Lab 12 HB 11-26-07 Magnetic Field of a Circular Coil Lab 12 1 Magnetic Field of a Circular Coil Lab 12 Equipment- coil apparatus, BK Precision 2120B oscilloscope, Fluke multimeter, Wavetek FG3C function generator,

More information

Eðlisfræði 2, vor 2007

Eðlisfræði 2, vor 2007 [ Assignment View ] [ Pri Eðlisfræði 2, vor 2007 28. Sources of Magnetic Field Assignment is due at 2:00am on Wednesday, March 7, 2007 Credit for problems submitted late will decrease to 0% after the deadline

More information

Magnetism, a history. Existence of a Magnetic Field, B. Magnetic Force on a charged particle. The particle in the figure

Magnetism, a history. Existence of a Magnetic Field, B. Magnetic Force on a charged particle. The particle in the figure Existence of a Magnetic Field, B Magnetic field, B, is a vector You may be familiar with bar magnets have a magnetic field similar to electric field of dipoles Amazing experimental finding: there is a

More information

University of California, Berkeley Physics H7B Spring 1999 (Strovink) SOLUTION TO PROBLEM SET 10 Solutions by P. Pebler

University of California, Berkeley Physics H7B Spring 1999 (Strovink) SOLUTION TO PROBLEM SET 10 Solutions by P. Pebler University of California, Berkeley Physics H7B Spring 1999 (Strovink) SOLUTION TO PROBLEM SET 10 Solutions by P Pebler 1 Purcell 66 A round wire of radius r o carries a current I distributed uniformly

More information

Multiple Choice Questions for Physics 1 BA113 Chapter 23 Electric Fields

Multiple Choice Questions for Physics 1 BA113 Chapter 23 Electric Fields Multiple Choice Questions for Physics 1 BA113 Chapter 23 Electric Fields 63 When a positive charge q is placed in the field created by two other charges Q 1 and Q 2, each a distance r away from q, the

More information

IMPORTANT NOTE ABOUT WEBASSIGN:

IMPORTANT NOTE ABOUT WEBASSIGN: Week 8 homework IMPORTANT NOTE ABOUT WEBASSIGN: In the WebAssign versions of these problems, various details have been changed, so that the answers will come out differently. The method to find the solution

More information

Electromagnetism Laws and Equations

Electromagnetism Laws and Equations Electromagnetism Laws and Equations Andrew McHutchon Michaelmas 203 Contents Electrostatics. Electric E- and D-fields............................................. Electrostatic Force............................................2

More information

Chapter 22: Electric motors and electromagnetic induction

Chapter 22: Electric motors and electromagnetic induction Chapter 22: Electric motors and electromagnetic induction The motor effect movement from electricity When a current is passed through a wire placed in a magnetic field a force is produced which acts on

More information

Name: Date: Regents Physics Mr. Morgante UNIT 4B Magnetism

Name: Date: Regents Physics Mr. Morgante UNIT 4B Magnetism Name: Regents Physics Date: Mr. Morgante UNIT 4B Magnetism Magnetism -Magnetic Force exists b/w charges in motion. -Similar to electric fields, an X stands for a magnetic field line going into the page,

More information

Section V.4: Cross Product

Section V.4: Cross Product Section V.4: Cross Product Definition The cross product of vectors A and B is written as A B. The result of the cross product A B is a third vector which is perpendicular to both A and B. (Because the

More information

1. A wire carries 15 A. You form the wire into a single-turn circular loop with magnetic field 80 µ T at the loop center. What is the loop radius?

1. A wire carries 15 A. You form the wire into a single-turn circular loop with magnetic field 80 µ T at the loop center. What is the loop radius? CHAPTER 3 SOURCES O THE MAGNETC ELD 1. A wire carries 15 A. You form the wire into a single-turn circular loop with magnetic field 8 µ T at the loop center. What is the loop radius? Equation 3-3, with

More information

* Biot Savart s Law- Statement, Proof Applications of Biot Savart s Law * Magnetic Field Intensity H * Divergence of B * Curl of B. PPT No.

* Biot Savart s Law- Statement, Proof Applications of Biot Savart s Law * Magnetic Field Intensity H * Divergence of B * Curl of B. PPT No. * Biot Savart s Law- Statement, Proof Applications of Biot Savart s Law * Magnetic Field Intensity H * Divergence of B * Curl of B PPT No. 17 Biot Savart s Law A straight infinitely long wire is carrying

More information

Chapter 31: Induction and Inductance

Chapter 31: Induction and Inductance Chapter 31: Induction and Inductance In Ch 30 we learned the following about magnetic fields: a) A magnetic field can exert a force on a current carrying wire b) If the wire is a closed loop then the magnetic

More information

Date: Deflection of an Electron in a Magnetic Field

Date: Deflection of an Electron in a Magnetic Field Name: Partners: Date: Deflection of an Electron in a Magnetic Field Purpose In this lab, we use a Cathode Ray Tube (CRT) to measure the effects of an electric and magnetic field on the motion of a charged

More information

Faraday s Law of Induction

Faraday s Law of Induction Chapter 10 Faraday s Law of Induction 10.1 Faraday s Law of Induction...10-10.1.1 Magnetic Flux...10-3 10.1. Lenz s Law...10-5 10. Motional EMF...10-7 10.3 Induced Electric Field...10-10 10.4 Generators...10-1

More information

Eðlisfræði 2, vor 2007

Eðlisfræði 2, vor 2007 [ Assignment View ] [ Print ] Eðlisfræði 2, vor 2007 30. Inductance Assignment is due at 2:00am on Wednesday, March 14, 2007 Credit for problems submitted late will decrease to 0% after the deadline has

More information

Homework #11 203-1-1721 Physics 2 for Students of Mechanical Engineering

Homework #11 203-1-1721 Physics 2 for Students of Mechanical Engineering Homework #11 203-1-1721 Physics 2 for Students of Mechanical Engineering 2. A circular coil has a 10.3 cm radius and consists of 34 closely wound turns of wire. An externally produced magnetic field of

More information

Modern Physics Laboratory e/m with Teltron Deflection Tube

Modern Physics Laboratory e/m with Teltron Deflection Tube Modern Physics Laboratory e/m with Teltron Deflection Tube Josh Diamond & John Cummings Fall 2010 Abstract The deflection of an electron beam by electric and magnetic fields is observed, and the charge

More information

VELOCITY, ACCELERATION, FORCE

VELOCITY, ACCELERATION, FORCE VELOCITY, ACCELERATION, FORCE velocity Velocity v is a vector, with units of meters per second ( m s ). Velocity indicates the rate of change of the object s position ( r ); i.e., velocity tells you how

More information

physics 112N magnetic fields and forces

physics 112N magnetic fields and forces physics 112N magnetic fields and forces bar magnet & iron filings physics 112N 2 bar magnets physics 112N 3 the Earth s magnetic field physics 112N 4 electro -magnetism! is there a connection between electricity

More information

Exam 2 Practice Problems Part 2 Solutions

Exam 2 Practice Problems Part 2 Solutions Problem 1: Short Questions MASSACHUSETTS INSTITUTE OF TECHNOLOGY Department of Physics 8. Exam Practice Problems Part Solutions (a) Can a constant magnetic field set into motion an electron, which is initially

More information

Q28.1 A positive point charge is moving to the right. The magnetic field that the point charge produces at point P (see diagram below) P

Q28.1 A positive point charge is moving to the right. The magnetic field that the point charge produces at point P (see diagram below) P Q28.1 A positive point charge is moving to the right. The magnetic field that the point charge produces at point P (see diagram below) P r + v r A. points in the same direction as v. B. points from point

More information

AP2 Electrostatics. Three point charges are located at the corners of a right triangle as shown, where q 1. are each 1 cm from q 3.

AP2 Electrostatics. Three point charges are located at the corners of a right triangle as shown, where q 1. are each 1 cm from q 3. Three point charges are located at the corners of a right triangle as shown, where q 1 = q 2 = 3 µc and q 3 = -4 µc. If q 1 and q 2 are each 1 cm from q 3, what is the magnitude of the net force on q 3?

More information

Magnetic Field and Magnetic Forces

Magnetic Field and Magnetic Forces Chapter 27 Magnetic Field and Magnetic Forces PowerPoint Lectures for University Physics, Thirteenth Edition Hugh D. Young and Roger A. Freedman Lectures by Wayne Anderson Goals for Chapter 27 Magnets

More information

Physics 210 Q ( PHYSICS210BRIDGE ) My Courses Course Settings

Physics 210 Q ( PHYSICS210BRIDGE ) My Courses Course Settings 1 of 16 9/7/2012 1:10 PM Logged in as Julie Alexander, Instructor Help Log Out Physics 210 Q1 2012 ( PHYSICS210BRIDGE ) My Courses Course Settings Course Home Assignments Roster Gradebook Item Library

More information

Announcements. Dry Friction

Announcements. Dry Friction Announcements Dry Friction Today s Objectives Understand the characteristics of dry friction Draw a FBD including friction Solve problems involving friction Class Activities Applications Characteristics

More information

Rotational inertia (moment of inertia)

Rotational inertia (moment of inertia) Rotational inertia (moment of inertia) Define rotational inertia (moment of inertia) to be I = Σ m i r i 2 or r i : the perpendicular distance between m i and the given rotation axis m 1 m 2 x 1 x 2 Moment

More information

Physics 1A Lecture 10C

Physics 1A Lecture 10C Physics 1A Lecture 10C "If you neglect to recharge a battery, it dies. And if you run full speed ahead without stopping for water, you lose momentum to finish the race. --Oprah Winfrey Static Equilibrium

More information

Linear DC Motors. 15.1 Magnetic Flux. 15.1.1 Permanent Bar Magnets

Linear DC Motors. 15.1 Magnetic Flux. 15.1.1 Permanent Bar Magnets Linear DC Motors The purpose of this supplement is to present the basic material needed to understand the operation of simple DC motors. This is intended to be used as the reference material for the linear

More information

MFF 3a: Charged Particle and a Straight Current-Carrying Wire... 2

MFF 3a: Charged Particle and a Straight Current-Carrying Wire... 2 MFF 3a: Charged Particle and a Straight Current-Carrying Wire... 2 MFF3a RT1: Charged Particle and a Straight Current-Carrying Wire... 3 MFF3a RT2: Charged Particle and a Straight Current-Carrying Wire...

More information

Fall 12 PHY 122 Homework Solutions #10

Fall 12 PHY 122 Homework Solutions #10 Fall 12 PHY 122 Homework Solutions #10 HW10: Ch.30 Q5, 8, 15,17, 19 P 1, 3, 9, 18, 34, 36, 42, 51, 66 Chapter 30 Question 5 If you are given a fixed length of wire, how would you shape it to obtain the

More information

If you put the same book on a tilted surface the normal force will be less. The magnitude of the normal force will equal: N = W cos θ

If you put the same book on a tilted surface the normal force will be less. The magnitude of the normal force will equal: N = W cos θ Experiment 4 ormal and Frictional Forces Preparation Prepare for this week's quiz by reviewing last week's experiment Read this week's experiment and the section in your textbook dealing with normal forces

More information

www.mathsbox.org.uk Displacement (x) Velocity (v) Acceleration (a) x = f(t) differentiate v = dx Acceleration Velocity (v) Displacement x

www.mathsbox.org.uk Displacement (x) Velocity (v) Acceleration (a) x = f(t) differentiate v = dx Acceleration Velocity (v) Displacement x Mechanics 2 : Revision Notes 1. Kinematics and variable acceleration Displacement (x) Velocity (v) Acceleration (a) x = f(t) differentiate v = dx differentiate a = dv = d2 x dt dt dt 2 Acceleration Velocity

More information

Quiz: Work and Energy

Quiz: Work and Energy Quiz: Work and Energy A charged particle enters a uniform magnetic field. What happens to the kinetic energy of the particle? (1) it increases (2) it decreases (3) it stays the same (4) it changes with

More information

PHYS 222 Spring 2012 Final Exam. Closed books, notes, etc. No electronic device except a calculator.

PHYS 222 Spring 2012 Final Exam. Closed books, notes, etc. No electronic device except a calculator. PHYS 222 Spring 2012 Final Exam Closed books, notes, etc. No electronic device except a calculator. NAME: (all questions with equal weight) 1. If the distance between two point charges is tripled, the

More information

Magnetic Force. For centuries, humans observed strange force. Between iron and special stones called lodestones. Force couldn't be gravity or electric

Magnetic Force. For centuries, humans observed strange force. Between iron and special stones called lodestones. Force couldn't be gravity or electric MAGNETIC FIELD Magnetic Force For centuries, humans observed strange force Between iron and special stones called lodestones Force couldn't be gravity or electric Not enough mass or electric charge to

More information

TEACHER S CLUB EXAMS GRADE 11. PHYSICAL SCIENCES: PHYSICS Paper 1

TEACHER S CLUB EXAMS GRADE 11. PHYSICAL SCIENCES: PHYSICS Paper 1 TEACHER S CLUB EXAMS GRADE 11 PHYSICAL SCIENCES: PHYSICS Paper 1 MARKS: 150 TIME: 3 hours INSTRUCTIONS AND INFORMATION 1. This question paper consists of 12 pages, two data sheets and a sheet of graph

More information

Problem 1 (25 points)

Problem 1 (25 points) MASSACHUSETTS INSTITUTE OF TECHNOLOGY Department of Physics 8.02 Spring 2012 Exam Three Solutions Problem 1 (25 points) Question 1 (5 points) Consider two circular rings of radius R, each perpendicular

More information

Homework 4. problems: 5.61, 5.67, 6.63, 13.21

Homework 4. problems: 5.61, 5.67, 6.63, 13.21 Homework 4 problems: 5.6, 5.67, 6.6,. Problem 5.6 An object of mass M is held in place by an applied force F. and a pulley system as shown in the figure. he pulleys are massless and frictionless. Find

More information

Ampere's Law. Introduction. times the current enclosed in that loop: Ampere's Law states that the line integral of B and dl over a closed path is 0

Ampere's Law. Introduction. times the current enclosed in that loop: Ampere's Law states that the line integral of B and dl over a closed path is 0 1 Ampere's Law Purpose: To investigate Ampere's Law by measuring how magnetic field varies over a closed path; to examine how magnetic field depends upon current. Apparatus: Solenoid and path integral

More information

Physics Notes Class 11 CHAPTER 5 LAWS OF MOTION

Physics Notes Class 11 CHAPTER 5 LAWS OF MOTION 1 P a g e Inertia Physics Notes Class 11 CHAPTER 5 LAWS OF MOTION The property of an object by virtue of which it cannot change its state of rest or of uniform motion along a straight line its own, is

More information

General Physics (PHY 2140)

General Physics (PHY 2140) General Physics (PHY 2140) Lecture 12 Electricity and Magnetism Magnetism Magnetic fields and force Application of magnetic forces http://www.physics.wayne.edu/~apetrov/phy2140/ Chapter 19 1 Department

More information

Solution Derivations for Capa #11

Solution Derivations for Capa #11 Solution Derivations for Capa #11 1) A horizontal circular platform (M = 128.1 kg, r = 3.11 m) rotates about a frictionless vertical axle. A student (m = 68.3 kg) walks slowly from the rim of the platform

More information

v 2 = v a(x x 0 ) and v = 0 a = v2 0 2d = K md F net = qe = ma E = ma e = K ed = V/m dq = λ ds de r = de cosθ = 1 λ ds = r dθ E r =

v 2 = v a(x x 0 ) and v = 0 a = v2 0 2d = K md F net = qe = ma E = ma e = K ed = V/m dq = λ ds de r = de cosθ = 1 λ ds = r dθ E r = Physics 11 Honors Final Exam Spring 003 Name: Section: Closed book exam. Only one 8.5 11 formula sheet (front and back side) can be used. Calculators are allowed. Use the scantron forms (pencil only!)

More information

12. The current in an inductor is changing at the rate of 100 A/s, and the inductor emf is 40 V. What is its self-inductance?

12. The current in an inductor is changing at the rate of 100 A/s, and the inductor emf is 40 V. What is its self-inductance? 12. The current in an inductor is changing at the rate of 100 A/s, and the inductor emf is 40 V. What is its self-inductance? From Equation 32-5, L = -E=(dI =dt) = 40 V=(100 A/s) = 0.4 H. 15. A cardboard

More information

Last Name: First Name: Physics 102 Spring 2007: Exam #1 Multiple-Choice Questions 1. Two small conducting spheres attract one another electrostatically. This can occur for a variety of reasons. Which of

More information

7. Kinetic Energy and Work

7. Kinetic Energy and Work Kinetic Energy: 7. Kinetic Energy and Work The kinetic energy of a moving object: k = 1 2 mv 2 Kinetic energy is proportional to the square of the velocity. If the velocity of an object doubles, the kinetic

More information