# Exam 2 Solutions. ε 3. ε 1. Problem 1

Size: px
Start display at page:

Transcription

1 Exam 2 Solutions Problem 1 In the circuit shown, R1=100 Ω, R2=25 Ω, and the ideal batteries have EMFs of ε1 = 6.0 V, ε2 = 3.0 V, and ε3 = 1.5 V. What is the magnitude of the current flowing through resistor R2? (1) 60 ma (2) 30 ma (3) 40 ma (4) 20 ma (5) 240 ma Let s use Kirchoff s loop rule for the upper loop, where we go around clockwise from point b: ε 3 + ε 2 ε 1 i 2 R 2 = 0 i 2 = ε 3 + ε 2 ε 1 R 2 = = 0.06V i 2 = 60 mv Problem 2 In the circuit shown, R1=15 Ω, R2=60 Ω, and the ideal batteries have EMFs of ε1 = 4.0 V and ε2 = 9.0 V. What is the magnitude of the current flowing through resistor R1? (1) 0.3 A (2) 0.15 A (3) 0.5 A (4) 0.9 A (5) 0.08 A Let s use Kirchoff s loop rule for the left loop, where we go around clockwise: ε 2 i 1 R 1 ε 1 = 0 i 1 = ε 2 ε 1 R 1 = 5 15 = 0.33

2 Problem 3 In the circuit shown, the ideal batteries have EMFs of ε1 = 12 V and ε2 = 6 V and the resistances are R1=30 Ω and R2=10 Ω. If the potential at Q is defined to be 4.5 V, what is the potential at P? (1) 15.0 V (2) 10.5 V (3) 6.0 V (4) 24.0 V (5) - 10 V First solve for the current in the circuit: ε 1 ir 2 ε 2 ir 1 = 0 i = ε 1 ε 2 R 1 + R 2 = 6 40 = 0.15 Now let s add the potential difference to go from point Q to P: V P = V Q + ε 1 ir 2 V P = ( ) = 15

3 Problem 4 In the shown figure, R1 = R2 = R3 = 50 Ω, R4 = 100 Ω, and the ideal battery has EMF = 6 V. What is the equivalent resistance of the circuit? (1) 70 Ω (2) 120 Ω (3) 20 Ω (4) 90 Ω (5) 250 Ω The 3 resistors R2, R3, and R4 are in parallel with equivalent resistance: R 234 = R 2 R 3 R = = 20 Then adding resistor R1 in series we have Req=50+20=70Ω Problem 5 A capacitor with an initial potential difference of 50 V is discharged through a 10 6 Ω resistor when a switch between them is closed at t=0. At t=2 s, the potential difference across the capacitor is 25 V. What is the capacitance of the capacitor? (1) 2.9x10-6 F (2) 2.0x10-6 F (3) 3.5x10 5 F (4) 3.5x10-7 F (5) 0.5 F V = q( t) C = q 0 V = V 0 e t/rc V 0 = 50 V 2 C e t/rc ( ) = 25 = 50e 2/RC ln2 = 2 RC 2 C = Rln2 = F

4 Problem 6 An ion of charge q= +2e and unknown mass is sent into a region with a uniform magnetic field of magnitude B=0.5 T as shown in the figure. The charged ion makes a U- turn in the region of the magnetic field as a semicircle of radius 1 m and exits after a time t=7.8 x10-6 s. What is the mass of the ion in kg? (1) 4.0x10-25 (2) 1.6x10-19 (3) 2.0x10-25 (4) 1.2x10-24 (5) 1.0x10-25 We can use the relation between momentum and radius of curvature for a particle moving in a magnetic field: mv = qbr m = qbr v The velocity can be found from the time it takes to complete the semicircle: d = πr = vt v = πr t = π s = m/s So the mass is given by m = qbr v = 2eBr 2( )( 0.5)1 = = kg v This is the mass of Uranium.

5 Problem 7 A beam of electrons (``cathode rays'') with a velocity of v = 3.0x10 7 i m/s is sent into a region where there is a uniform magnetic field of B = 5.0x10-4 j T. What electric field E is necessary (direction and magnitude) so that the electrons continue traveling in a straight line without deflection by the magnetic field? (1) - 1.5x10 4 k T (2) 1.5x10 4 k T (3) 5.0x10-4 j T (4) - 5.0x10-4 j T (5) 2.4x10-15 i T The Lorentz Force equation is F = q E + v B ( ) So the condition of no net force (so no deflection) is: E = v B ( ) ( ĵ) = î = ˆk Problem 8 An electron moves in the - i direction, through a uniform magnetic field in the - j direction. The magnetic force on the electron is in the direction: (1) - k (2) k (3) - j (4) j (5) - i The magnetic force is F B = qv B So working with directions only: F = ( e) ( î ) ( ĵ ) = ˆk

6 Problem 9 The figure shows a rectangular loop of wire of dimensions 10 cm by 5.0 cm. It carries a current of 0.2 A and it is hinged along one long side. It is mounted in the xy plane, and it makes an angle of Θ=30 to the direction of a uniform magnetic field of 0.25 T. What is the magnitude of the torque acting on the loop about the hinge line? (1) 2.2x10-4 N m (2) 1.3x10-4 N m (3) 5.0x10-3 N m (4) 1.0x10-3 N m (5) 0 Nm The torque on the loop is calculated below. Note that the angle between the magnetic dipole moment and the magnetic field is 90 + θ, or 120. τ = µ B τ = µbsinθ ( )( 0.05m) ( 0.01m) ( )( 0.05m) ( 0.01m) 0.25T µ = ia = 0.2A τ = 0.2A ( )sin120 τ = ( 0.2A) ( 0.05m) ( 0.01m) ( 0.25T ) τ = Nm 3 2 Problem 10 A magnetic field CANNOT: (1) change the kinetic energy of a charge (2) exert a force on a charge (3) accelerate a charge (4) change the momentum of a charge (5) exist The only thing a magnetic field cannot do is perform work on an object, hence it cannot change the kinetic energy of a charge.

7 Problem 11 Two wires are aligned with x- and y- axes and carry currents I1 along x- axis and I2 along y- axis as shown. Which of the four quadrants have points in (x, y)- plane where the magnetic field is zero. (a) 1 & 3 (b) 2 & 4 (c) all (d) none (e) the answer depends on the relative magnitudes of the two currents Using right hand rule (align the right hand thumb along the current and curl the fingers around the thumb), the direction of magnetic fields induced by the currents are as follows: Current Quadrant 1 Quadrant 2 Quadrant 3 Quadrant 4 I1 out out in in I2 in out out in Hence, the two fields can potentially cancel only in quadrants 1 and 3, where they point in different directions. This eliminates answers (b) and (c). The magnitudes of fields in Quadrant 1 are: B 1 = µ I 0 1 and B 2π y 2 = µ I 0 2 2π x The two fields are equal in magnitude along the line: y = I 1 I 2 x Hence, the net field along this line is zero. The exact same argumentation holds true for Quadrant 3. Therefore, the right answer is (a)

8 Problem 12 One wire is aligned with x- axis and carries currents I1=1A. Another wire carries current I2=2 A out of page through the point (x, y)=(0 m, 1 m) as shown. What is the magnitude of the magnetic field in Tesla at point P(3 m, 1 m)? (a) 2.4E- 7 (b) (b) 3.3E- 7 (c) (c) 6.7E- 8 (d) (d) 1.5E- 6 (e) (e) 4.2E- 7 Using right hand rule (align the right hand thumb along the current and curl the fingers around the thumb), the direction of magnetic fields induced by the two currents at point P are as follows: Current I1 out of the page; its magnitude is B 1 = µ 0 I 1 2π y = = T Current I2 up; its magnitude is B 2 = µ 0 I 2 2π x = = T Since the two fields are perpendicular to each other, we use the Pythagorean theorem for calculating the total field magnitude: B TOT = T

9 Problem 13 A current I through an infinitely long wire increases. A square loop made of a conductor is placed next to the wire carrying the current as shown (the loop and the wire are in the plane of the sheet). What is the direction of a net force exerted on the loop? (a) down (b) up (c) out of the page (d) into the page (e) zero As the current increases, so does the flux of magnetic field through the loop. The field is into the page, so is its flux through the loop. Since the current I is increasing, the flux is also increasing. The change in the flux is into the page. Induced EMF, E = dφ, is dt counterclockwise (right hand thumb is along the change in the flux, curl your fingers, and change the direction). The induced currents (shown in red), being in the magnetic field of the wire, will experience forces as follows: Up side of the loop: force F1, down Left side of the loop: F2, right Bottom side of the loop: force F3, up, but it is smaller than F1 as the filed is weaker away from the wire (B ~ I/r) Right side of the loop: F4, left, same in magnitude as F2, by symmetry Therefore, F2 and F4 cancel each other and the net force of F1 and F3 points down.

10 Problem 14 A prism with sides 2, 3, 4 cm is placed in uniform magnetic field of 1 T pointing along y- direction (see drawing). Find the magnetic field flux (in Webbers) through the entire surface area of the prism. (a) 0 (b) (c) (d) (e) Φ = B A cosθ, where θ is an angle between a vector normal to a surface of area A and a vector of a magnetic field of strength B. a) The flux through the front, back, and bottom sides of the prism are zero since the field is parallel to these three surfaces (θ=90, cosθ=0). b) The flux through the left side is (1 T) ( m 2 ), inward c) The right side of the prism has sides 2 cm (as marked) and 5 cm (from Pythagorean theorem). The angle between a vector normal to a surface of the right side and the magnetic field vector is the same as top angle of the front side of the prism. Cosine of that angle is 4/5. Therefore, the flux through the right side is (1 T) ( m 2 ) (4/5), outward. d) The net flux through all five surfaces is: ( ) + (+0.008) = 0

11 Problem 15 Magnetic field inside the solenoid is B = µ 0 In, where n=1000/(0.2 m). Induced EMF is E = ΔΦ = Ba2 = µ 0In a 2 = µ 0I (N / L) a 2 = 4π (1000 / 0.2) = V Problem 16 Induced EMF is E = ΔΦ = Bπr2 N ( Bπr 2 N) = 2Bπr2 N = = V

12 Problem 17 The magnetic filed integral over a loop is related to the total current going through the loop. The current is counted as positive if it is in the same direction as the right hand thumb points, when fingers are curled around the loop in the direction of integration. Bds = µ 0 I TOT = 4π 10 7 ( ) = 4π 10 7 Tm Problem 18 E = dφ dt = d dt Bπr2 N = d dt B 0e t/τ πr 2 N = B 0 πr 2 N d dt e t/τ = B 0 πr 2 N 1 τ e t/τ

13 Problem 19 The total energy U is energy density u = 1 2µ 0 B 2 times the inner volume of the solenoid πr 2 L : 1 U = B 2 2µ 0 πr2 L ( ) = ( ) = J Problem 20 The sum of difference potentials over all elements in the closed loop of any circuit is zero. Right after closing the switch, the sum of difference potentials over all elements in the circuit is: ΔV battery + ΔV inductor + ΔV fuse + ΔV switch = 0 E + L di dt = 0 di dt = E L I = E L t From where, it takes 1.5 s to reach 3A current.

### Exam 2 Solutions. Note that there are several variations of some problems, indicated by choices in parentheses.

Exam 2 Solutions Note that there are several variations of some problems, indicated by choices in parentheses. Problem 1 Part of a long, straight insulated wire carrying current i is bent into a circular

### Louisiana State University Physics 2102, Exam 3 April 2nd, 2009.

PRINT Your Name: Instructor: Louisiana State University Physics 2102, Exam 3 April 2nd, 2009. Please be sure to PRINT your name and class instructor above. The test consists of 4 questions (multiple choice),

### 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

### PHYS 241 EXAM #2 November 9, 2006

1. ( 5 points) A resistance R and a 3.9 H inductance are in series across a 60 Hz AC voltage. The voltage across the resistor is 23 V and the voltage across the inductor is 35 V. Assume that all voltages

### 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),

### 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

### Circuits Capacitance of a parallel-plate capacitor : C = κ ε o A / d. (ρ = resistivity, L = length, A = cross-sectional area) Resistance : R = ρ L / A

k = 9.0 x 109 N m2 / C2 e = 1.60 x 10-19 C ε o = 8.85 x 10-12 C2 / N m2 Coulomb s law: F = k q Q / r2 (unlike charges attract, like charges repel) Electric field from a point charge : E = k q / r2 ( towards

### The next two questions pertain to the situation described below. Consider a parallel plate capacitor with separation d:

PHYS 102 Exams Exam 2 PRINT (A) The next two questions pertain to the situation described below. Consider a parallel plate capacitor with separation d: It is connected to a battery with constant emf V.

### a. Clockwise. b. Counterclockwise. c. Out of the board. d. Into the board. e. There will be no current induced in the wire

Physics 1B Winter 2012: Final Exam For Practice Version A 1 Closed book. No work needs to be shown for multiple-choice questions. The first 10 questions are the makeup Quiz. The remaining questions are

### 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.

### Physics 1302W.400 Lecture 33 Introductory Physics for Scientists and Engineering II

Physics 1302W.400 Lecture 33 Introductory Physics for Scientists and Engineering II In today s lecture, we will discuss generators and motors. Slide 30-1 Announcement Quiz 4 will be next week. The Final

### = 8.89x10 9 N m 2 /C 2

PHY303L Useful Formulae for Test 2 Magnetic Force on a moving charged particle F B = q v B Magnetic Force on a current carrying wire F B = i L B Magnetic dipole moment µ = NiA Torque on a magnetic dipole:

### PHY 131 Review Session Fall 2015 PART 1:

PHY 131 Review Session Fall 2015 PART 1: 1. Consider the electric field from a point charge. As you move farther away from the point charge, the electric field decreases at a rate of 1/r 2 with r being

### = e = e 3 = = 4.98%

PHYS 212 Exam 2 - Practice Test - Solutions 1E In order to use the equation for discharging, we should consider the amount of charge remaining after three time constants, which would have to be q(t)/q0.

### 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

### PHY 2049 SPRING 2001 EXAM 3

PHY 2049 SPING 2001 EXAM 3 1. A negatively charged particle moves with velocity v in a uniform magnetic field as shown in figure (both vector and vector v are in the plane of the paper). What is the direction

### PHY2049 Fall11. Final Exam Solutions (1) 700 N (2) 350 N (3) 810 N (4) 405 N (5) 0 N

Exam Solutions 1. Three charges form an equilateral triangle of side length d = 2 cm. The top charge is q3 = 3 μc, while the bottom two are q1 = q2 = - 6 μc. What is the magnitude of the net force acting

### Phys102 Final-132 Zero Version Coordinator: A.A.Naqvi Wednesday, May 21, 2014 Page: 1

Coordinator: A.A.Naqvi 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? A).3 V

### Physics 2212 GH Quiz #4 Solutions Spring 2016

Physics 2212 GH Quiz #4 Solutions Spring 2016 I. (18 points) A bar (mass m, length L) is connected to two frictionless vertical conducting rails with loops of wire, in the presence of a uniform magnetic

### PHY 114 Summer Midterm 2 Solutions

PHY 114 Summer 009 - Midterm Solutions Conceptual Question 1: Can an electric or a magnetic field, each constant in space and time, e used to accomplish the actions descried elow? Explain your answers.

### Physics 1308 Exam 2 Summer 2015

Physics 1308 Exam 2 Summer 2015 E2-01 2. The direction of the magnetic field in a certain region of space is determined by firing a test charge into the region with its velocity in various directions in

### 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

### Magnets. Domain = small magnetized region of a magnetic material. all the atoms are grouped together and aligned

Magnetic Fields Magnets Domain = small magnetized region of a magnetic material all the atoms are grouped together and aligned Magnets Ferromagnetic materials domains can be forced to line up by applying

### 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

### Questions A hair dryer is rated as 1200 W, 120 V. Its effective internal resistance is (A) 0.1 Ω (B) 10 Ω (C) 12Ω (D) 120 Ω (E) 1440 Ω

Questions 4-41 36. Three 1/ µf capacitors are connected in series as shown in the diagram above. The capacitance of the combination is (A).1 µf (B) 1 µf (C) /3 µf (D) ½ µf (E) 1/6 µf 37. A hair dryer is

### Name (Print): 4 Digit ID: Section:

Physics 11 Sample Common Exam 3: Sample 5 Name (Print): 4 Digit ID: Section: Honors Code Pledge: As an NJIT student I, pledge to comply with the provisions of the NJIT Academic Honor Code. I assert that

### Physics 208, Spring 2016 Exam #3

Physics 208, Spring 206 Exam #3 A Name (Last, First): ID #: Section #: You have 75 minutes to complete the exam. Formulae are provided on an attached sheet. You may NOT use any other formula sheet. You

### Final Exam: Physics Spring, 2017 May 8, 2017 Version 01

Final Exam: Physics2331 - Spring, 2017 May 8, 2017 Version 01 NAME (Please Print) Your exam should have 11 pages. This exam consists of 18 multiple-choice questions (2 points each, worth 36 points), and

### Physics 112. Study Notes for Exam II

Chapter 20 Electric Forces and Fields Physics 112 Study Notes for Exam II 4. Electric Field Fields of + and point charges 5. Both fields and forces obey (vector) superposition Example 20.5; Figure 20.29

### Physics 2020 Exam 2 Constants and Formulae

Physics 2020 Exam 2 Constants and Formulae Useful Constants k e = 8.99 10 9 N m 2 /C 2 c = 3.00 10 8 m/s ɛ = 8.85 10 12 C 2 /(N m 2 ) µ = 4π 10 7 T m/a e = 1.602 10 19 C h = 6.626 10 34 J s m p = 1.67

### Exam 2 Solutions. R 1 a. (a) [6 points] Find the voltage drop between points a and b: Vab = Va Vb. , the current i 2 is found by:

PHY06 0--04 Exam Solutions R a + R R 3. Consider the circuit aboe. The battery supplies an EMF of 6.0 V, and the resistances of the 3 resistors are R 00Ω, R 5Ω, and R 3 75Ω (a) [6 points] Find the oltage

### 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

### Physics 2135 Exam 2 March 22, 2016

Exam Total Physics 2135 Exam 2 March 22, 2016 Key Printed Name: 200 / 200 N/A Rec. Sec. Letter: Five multiple choice questions, 8 points each. Choose the best or most nearly correct answer. B 1. An air-filled

### MASSACHUSETTS INSTITUTE OF TECHNOLOGY Department of Physics Spring 2014 Final Exam Equation Sheet. B( r) = µ o 4π

MASSACHUSETTS INSTITUTE OF TECHNOLOGY Department of Physics 8.02 Spring 2014 Final Exam Equation Sheet Force Law: F q = q( E ext + v q B ext ) Poynting Vector: S = ( E B) / µ 0 Force on Current Carrying

### 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

### Exam 2 Solutions. Answer: 3.0 W Solution: The total current is in the series circuit is 1 A, so the power dissipated in R 2 is i 2 R 2

Exam 2 Solutions Prof. Pradeep Kumar Prof. Paul Avery Mar. 21, 2012 1. A portable CD player does not have a power rating listed, but it has a label stating that it draws a maximum current of 159.0 ma.

### Physics 1308 Exam 2 Summer Instructions

Name: Date: Instructions All Students at SMU are under the jurisdiction of the Honor Code, which you have already signed a pledge to uphold upon entering the University. For this particular exam, you may

### Yell if you have any questions

Class 36: Outline Hour 1: Concept Review / Overview PRS Questions Possible Exam Questions Hour : Sample Exam Yell if you have any questions P36-1 Before Starting All of your grades should now be posted

### Version 001 HW 22 EM Induction C&J sizemore (21301jtsizemore) 1

Version 001 HW 22 EM Induction C&J sizemore (21301jtsizemore) 1 This print-out should have 35 questions. Multiple-choice questions may continue on the next column or page find all choices before answering.

### Physics 42 Exam 2 PRACTICE Name: Lab

Physics 42 Exam 2 PRACTICE Name: Lab 1 2 3 4 Conceptual Multiple Choice (2 points each) Circle the best answer. 1.Rank in order, from brightest to dimmest, the identical bulbs A to D. A. C = D > B > A

### Final on December Physics 106 R. Schad. 3e 4e 5c 6d 7c 8d 9b 10e 11d 12e 13d 14d 15b 16d 17b 18b 19c 20a

Final on December11. 2007 - Physics 106 R. Schad YOUR NAME STUDENT NUMBER 3e 4e 5c 6d 7c 8d 9b 10e 11d 12e 13d 14d 15b 16d 17b 18b 19c 20a 1. 2. 3. 4. This is to identify the exam version you have IMPORTANT

### 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

### Exam 2, Phy 2049, Spring Solutions:

Exam 2, Phy 2049, Spring 2017. Solutions: 1. A battery, which has an emf of EMF = 10V and an internal resistance of R 0 = 50Ω, is connected to three resistors, as shown in the figure. The resistors have

### LECTURE 17. Reminder Magnetic Flux

LECTURE 17 Motional EMF Eddy Currents Self Inductance Reminder Magnetic Flux Faraday s Law ε = dφ B Flux through one loop Φ B = BAcosθ da Flux through N loops Φ B = NBAcosθ 1 Reminder How to Change Magnetic

### Notes and Solved Problems for Common Exam 3 (Does not include Induction)

Notes and Solved Problems for Common Exam 3 (Does not include Induction) 8. MULTI LOOP CIRCUITS Key concepts: Multi loop circuits of batteries and resistors: loops, branches and junctions should be distinguished.

### Induction and Inductance

Welcome Back to Physics 1308 Induction and Inductance Michael Faraday 22 September 1791 25 August 1867 Announcements Assignments for Tuesday, November 6th: - Reading: Chapter 30.6-30.8 - Watch Videos:

### Magnetic Fields; Sources of Magnetic Field

This test covers magnetic fields, magnetic forces on charged particles and current-carrying wires, the Hall effect, the Biot-Savart Law, Ampère s Law, and the magnetic fields of current-carrying loops

### Physics 212 Midterm 2 Form A

1. A wire contains a steady current of 2 A. The charge that passes a cross section in 2 s is: A. 3.2 10-19 C B. 6.4 10-19 C C. 1 C D. 2 C E. 4 C 2. In a Physics 212 lab, Jane measures the current versus

### (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

MASSACHUSETTS INSTITUTE OF TECHNOLOGY Department of Physics: 8.02 Problem Solving: Faraday s Law & Inductance Section Table Names Faraday s Law In Chapter 10 of the 8.02 Course Notes, we have seen that

### Physics 6B Summer 2007 Final

Physics 6B Summer 2007 Final Question 1 An electron passes through two rectangular regions that contain uniform magnetic fields, B 1 and B 2. The field B 1 is stronger than the field B 2. Each field fills

### PHYS 212 Final Exam (Old Material) Solutions - Practice Test

PHYS 212 Final Exam (Old Material) Solutions - Practice Test 1E If the ball is attracted to the rod, it must be made of a conductive material, otherwise it would not have been influenced by the nearby

### Where k = 1. The electric field produced by a point charge is given by

Ch 21 review: 1. Electric charge: Electric charge is a property of a matter. There are two kinds of charges, positive and negative. Charges of the same sign repel each other. Charges of opposite sign attract.

### Inductance, RL Circuits, LC Circuits, RLC Circuits

Inductance, R Circuits, C Circuits, RC Circuits Inductance What happens when we close the switch? The current flows What does the current look like as a function of time? Does it look like this? I t Inductance

### Quiz 4 (Discussion Session) Phys 1302W.400 Spring 2018

Quiz 4 (Discussion ession) Phys 1302W.400 pring 2018 This group quiz consists of one problem that, together with the individual problems on Friday, will determine your grade for quiz 4. For the group problem,

### Exam 3 November 19, 2012 Instructor: Timothy Martin

PHY 232 Exam 3 October 15, 2012 Exam 3 November 19, 2012 Instructor: Timothy Martin Student Information Name and section: UK Student ID: Seat #: Instructions Answer the questions in the space provided.

### 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

### 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

### Physics 2B Winter 2012 Final Exam Practice

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

### Electromagnetic Induction! March 11, 2014 Chapter 29 1

Electromagnetic Induction! March 11, 2014 Chapter 29 1 Notes! Exam 4 next Tuesday Covers Chapters 27, 28, 29 in the book Magnetism, Magnetic Fields, Electromagnetic Induction Material from the week before

### b) (4) How large is the current through the 2.00 Ω resistor, and in which direction?

General Physics II Exam 2 - Chs. 19 21 - Circuits, Magnetism, EM Induction - Sep. 29, 2016 Name Rec. Instr. Rec. Time For full credit, make your work clear. Show formulas used, essential steps, and results

### 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,

### A) 4 B) 3 C) 2 D) 5 E) 6

Coordinator: Saleem Rao Monday, January 01, 2018 Page: 1 Q1. A standing wave having three nodes is set up in a string fixed at both ends. If the frequency of the wave is doubled, how many antinodes will

### PHYSICS ASSIGNMENT ES/CE/MAG. Class XII

PHYSICS ASSIGNMENT ES/CE/MAG Class XII MM : 70 1. What is dielectric strength of a medium? Give its value for vacuum. 1 2. What is the physical importance of the line integral of an electrostatic field?

### PHYS General Physics for Engineering II FIRST MIDTERM

Çankaya University Department of Mathematics and Computer Sciences 2010-2011 Spring Semester PHYS 112 - General Physics for Engineering II FIRST MIDTERM 1) Two fixed particles of charges q 1 = 1.0µC and

### Physics Jonathan Dowling. Final Exam Review

Physics 2102 Jonathan Dowling Physics 2102 Final Exam Review A few concepts: electric force, field and potential Electric force: What is the force on a charge produced by other charges? What is the force

### r where the electric constant

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

### 2. Thus, if the current is doubled while the inductance is constant, the stored energy increases by a factor of 4 and the correct choice is (d).

34 Chapter 7. The energy stored in an inductor of inductance and carrying current is PE 1. Thus, if the current is doubled while the inductance is constant, the stored energy increases by a factor of 4

### Exam 2 Solutions. Applying the junction rule: i 1 Applying the loop rule to the left loop (LL), right loop (RL), and the full loop (FL) gives:

PHY61 Eam Solutions 1. [8 points] In the circuit shown, the resistance R 1 = 1Ω. The batter voltages are identical: ε1 = ε = ε3 = 1 V. What is the current (in amps) flowing through the middle branch from

### 5) Ohm s Law gives the relationship between potential difference and current for a.

) During any process, the net charge of a closed system. a) increases b) decreases c) stays constant ) In equilibrium, the electric field in a conductor is. a) always changing b) a constant non-zero value

### Physics Lecture 40: FRI3 DEC

Physics 3 Physics 3 Lecture 4: FRI3 DEC Review of concepts for the final exam Electric Fields Electric field E at some point in space is defined as the force divided by the electric charge. Force on charge

### Q1. A wave travelling along a string is described by

Coordinator: Saleem Rao Wednesday, May 24, 2017 Page: 1 Q1. A wave travelling along a string is described by y( x, t) = 0.00327 sin(72.1x 2.72t) In which all numerical constants are in SI units. Find the

### University of the Philippines College of Science PHYSICS 72. Summer Second Long Problem Set

University of the Philippines College of Science PHYSICS 72 Summer 2012-2013 Second Long Problem Set INSTRUCTIONS: Choose the best answer and shade the corresponding circle on your answer sheet. To change

### 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

### PH 1120: Summary Homework 4 Solutions

PH 112: Summary Homework Solutions Term B8 1.(a) The path of the ion is a semicircle curving to the right from the point of entry, and terminating at the point X on the plate. (b) From the right hand rule,

### PHYS102 Previous Exam Problems. Induction

PHYS102 Previous Exam Problems CHAPTER 30 Induction Magnetic flux Induced emf (Faraday s law) Lenz law Motional emf 1. A circuit is pulled to the right at constant speed in a uniform magnetic field with

### Gen. Phys. II Exam 2 - Chs. 21,22,23 - Circuits, Magnetism, EM Induction Mar. 5, 2018

Gen. Phys. II Exam 2 - Chs. 21,22,23 - Circuits, Magnetism, EM Induction Mar. 5, 2018 Rec. Time Name For full credit, make your work clear. Show formulas used, essential steps, and results with correct

### 8. (6) Consider the circuit here with resistors R A, R B and R C. Rank the

General Physics II Exam 2 - Chs. 18B 21 - Circuits, Magnetism, EM Induction - Oct. 3, 2013 Name Rec. Instr. Rec. Time For full credit, make your work clear. Show formulas used, essential steps, and results

### MASSACHUSETTS INSTITUTE OF TECHNOLOGY Department of Physics Spring 2013 Exam 3 Equation Sheet. closed fixed path. ! = I ind.

MASSACHUSETTS INSTITUTE OF TECHNOLOGY Department of Physics 8.0 Spring 013 Exam 3 Equation Sheet Force Law: F q = q( E ext + v q B ext ) Force on Current Carrying Wire: F = Id s " B # wire ext Magnetic

### Profs. P. Avery, A. Rinzler, S. Hershfield. Final Exam Solution

PHY2049 Spring 2010 Profs. P. Avery, A. Rinzler, S. Hershfield Final Exam Solution 1. A proton traveling along the x axis (toward increasing x) has a speed of 1.0 10 5 m/s. At time t = 0 it enters a region

### Exam II. Solutions. Part A. Multiple choice questions. Check the best answer. Each question carries a value of 4 points. The wires repel each other.

Exam II Solutions Part A. Multiple choice questions. Check the best answer. Each question carries a value of 4 points. 1.! Concerning electric and magnetic fields, which of the following is wrong?!! A

### Student number: Question # Mark Maximum Mark. Multiple Choice 20

Name: Student number: Academic Honesty: Cheating in an examination includes the following: 1. the unauthorized sharing of material such as textbooks during an open book examination; 2. concealing information

### Problem Solving 6: Ampere s Law and Faraday s Law. Part One: Ampere s Law

MASSACHUSETTS INSTITUTE OF TECHNOLOGY Department of Physics: 8.02 Problem Solving 6: Ampere s Law and Faraday s Law Section Table Names Hand in one copy per group at the end of the Friday Problem Solving

### Final Exam Concept Map

Final Exam Concept Map Rule of thumb to study for any comprehensive final exam - start with what you know - look at the quiz problems. If you did not do well on the quizzes, you should certainly learn

### Physics 2220 Fall 2010 George Williams THIRD MIDTERM - REVIEW PROBLEMS

Physics 2220 Fall 2010 George Williams THIRD MIDTERM - REVIEW PROBLEMS Solution sets are available on the course web site. A data sheet is provided. Problems marked by "*" do not have solutions. 1. An

### Phys102 Final-163 Zero Version Coordinator: Saleem Rao Tuesday, August 22, 2017 Page: 1. = m/s

Coordinator: Saleem Rao Tuesday, August 22, 2017 Page: 1 Q1. A 125 cm long string has a mass of 2.00 g and a tension of 7.00 N. Find the lowest resonant frequency of the string. A) 2.5 Hz B) 53.0 Hz C)

### PRACTICE EXAM 1 for Midterm 2

PRACTICE EXAM 1 for Midterm 2 Multiple Choice Questions 1) The figure shows three identical lightbulbs connected to a battery having a constant voltage across its terminals. What happens to the brightness

### r where the electric constant

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

### Yell if you have any questions

Class 31: Outline Hour 1: Concept Review / Overview PRS Questions possible exam questions Hour : Sample Exam Yell if you have any questions P31 1 Exam 3 Topics Faraday s Law Self Inductance Energy Stored

### A 2. The potential difference across the capacitor is F m N m /C m. R R m m R m R m 0

30.53. Model: The charged metal spheres are isolated and far from each other and anything else. Solve: (a) The charge on a sphere of radius r, charged to a potential V 0 is given by the equations: The

### Physics 11b Lecture #10

Physics 11b Lecture #10 Magnetic Fields S&J Chapter 29 What We Did Last Time Electromotive forces (emfs) atteries are made of an emf and an internal resistance Resistor arithmetic R = R + R + R + + R series

### PHYS 1102 EXAM - II. SECTION: (Circle one) 001 (TH 9:30 AM to 10:45AM) 002 (TH 3:30 PM to 4:45 PM) You have 1 hr 45 minutes to complete the test

PHYS 1102 EXAM - II SECTION: (Circle one) 001 (TH 9:30 AM to 10:45AM) 002 (TH 3:30 PM to 4:45 PM) Your Name: Student ID: You have 1 hr 45 minutes to complete the test PLEASE DO NOT START TILL YOU ARE INSTRUCTED

### ( )( )( ) 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

### Physics 1B Spring 2010: Final Version A 1 COMMENTS AND REMINDERS:

Physics 1B Spring 2010: Final Version A 1 COMMENTS AND REMINDERS: Closed book. No work needs to be shown for multiple-choice questions. 1. Four charges are at the corners of a square, with B and C on opposite

### Physics 420 Fall 2004 Quiz 1 Wednesday This quiz is worth 6 points. Be sure to show your work and label your final answers.

Quiz 1 Wednesday This quiz is worth 6 points. Be sure to show your work and label your final answers. 1. A charge q 1 = +5.0 nc is located on the y-axis, 15 µm above the origin, while another charge q

### 1. A ring of radius α has a charge distribution on it that varies as λ(θ) = λ 0 sin(θ), where λ 0 > 0, as shown in the figure.

EACH OF THE LECTURE QUESTIONS 1-22 IS WORTH 5 POINTS I. COULOMB S LAW 1. A ring of radius α has a charge distribution on it that varies as λ(θ) = λ 0 sin(θ), where λ 0 > 0, as shown in the figure. What

### Physics 106, Section 1

Physics 106, Section 1 Magleby Exam 2, Summer 2012 Exam Cid You are allowed a pencil and a testing center calculator. No scratch paper is allowed. Testing center calculators only. 1. A circular coil lays

### 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