AP Physics C-Electricity and Magnetism Syllabus

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1 AP Physics C-Electricity and Magnetism Syllabus Overview Students enrolled in AP Physics C have already completed a year-long, accelerated physics course in their junior year. It is required that they also have completed, or are concurrently enrolled in a calculus course. The AP Physics C course will meet five, 70-minute periods a week, for a75-day second semester. Approximately one and a half weeks will be allowed for review immediately prior to the AP exams in May, and review sessions will also be held outside of class time during the second semester. Students are expected to take both the mechanics and electricity and magnetism AP exams in May. Students are highly recommended to review practice exams and other materials available through the College Board website. Textbook University Physics, 12 th Edition, Young and Freedman (Pearson, 2008) Materials Needed Textbook Three-ring binder with tab dividers and notebook paper Scientific calculator Pens and pencils WebAssign account and access to internet outside of the class Course Description This fast-paced semester-long course is designed to prepare students for the AP Physics C exam in electricity and magnetism. Topics will be covered in the order presented in chapters of the Young and Freedman textbook, University Physics. Calculus will be used throughout this course, with emphasis on both differential and integral methods. Concepts and problem-solving techniques will be introduced through a series of lectures, interactive demonstrations, question and answer sessions, problem-solving sessions, laboratory investigations, and homework assignments. The course will adhere to a tight schedule and students will be expected to put in minutes per night in homework. Major Units of Study Unit 1: Electrostatics: charge, field and energy Unit 2: Conductors, Capacitors and Dielectrics Unit 3: Electric Circuits Unit 4: Magnetic Fields Unit 5: Electromagnetism 1

2 Instructional Strategies Lectures: Formal presentation of concepts will typically proceed through lecture. Since students have already completed a year-long, advanced course in physics, lectures will be limited in number and duration to topics deemed to be sufficiently difficult or novel to students. Wherever possible, the instructional strategy will be to present students with phenomena first, and follow this with explication of concepts, working from concrete to abstract. Interactive demonstrations: The instructor will incorporate a variety of demonstrations within the course. The purpose of such demonstrations ranges from introduction of a new concept (introductory) to detailed analysis of a phenomena using labware probes (advanced.) Demonstrations will serve to support the conceptual understandings required for the electricity and magnetism curriculum. Question and Answer Sessions: Interaction and feedback make question and answer sessions essential in this course. Class-wide question and answer sessions will be incorporated on a daily basis, in a largely informal manner. These may center on student queries about lecture topics, demonstrations, labs or physics problems. Problem-Solving Sessions: Students will be allowed class time to work individually and collaboratively on solving problems assigned in class or as homework. These sessions are valuable insofar as they allow students to exchange strategies for mastering problem-solving techniques, and also allow students to interact with the instructor on a one-on-one basis. Laboratory Investigations: As a laboratory-based course, students should expect to spend at least 20% of class time (1 day for every 5 days of instruction) doing hands-on laboratory work. Labs are designed to reinforce concepts from the electricity and magnetism curriculum. Labs are designed to maximize student inquiry, collaborative interactions, authentic applications and open-ended creative solutions whenever possible. Students will often be required to generate their own procedures, decide which information is relevant, and then decide how to organize and analyze this information. Students will be required to consider and evaluate possible sources of error in laboratory investigations. Clear communication of ideas and findings through writing, tables, graphs and calculations will be demanded. Reports will typically document purpose, method, data, analysis and conclusions. Students will work collaboratively in teams of 2-3, but will generally submit their own individual final reports. Students are expected to compile a portfolio of their lab work for each semester. Homework: AP Physics is a college-level course! Students will need to invest minutes of time each evening on preparation for class. This will include online and written problem assignments, reading assignments, laboratory write-ups and general study time. Problemsolving assignments are of particular importance in the homework regimen. Problems found at the end of the textbook chapter will be assigned on a weekly basis. Students will submit answers through Webassign and will be expected to achieve a minimum percentage of correct responses after a limited number of allowed attempts. From these problem sets, students will also be asked to submit a subset of fully-worked out problems in writing. These problems should be submitted on loose leaf paper. 2

3 Assessment Strategies Philosophy: Assessment of Student Understanding: Since this course is fast-paced, it is essential that students prepare themselves in a daily manner for lessons. Toward this end, the instructor will assess students on a daily basis in either formative or summative manners. Students will be assessed formatively on a daily basis in a variety of ways, including o Formative: Although homework assignments and quizzes will comprise 20% of the classroom grade, the spirit of homework assessment is to provide formative feedback. Students will be given multiple opportunities to achieve full credit on problem assignments, encouraging them to revisit problems that they find especially difficult. On a weekly basis, students will be expected to successfully complete a minimum percentage of online problems. The instructor will also collect and provide feedback on students written problems on a weekly basis. Homework quizzes will be administered on a frequent basis to test student understanding and provide feedback for improvement. o Summative: Laboratory reports (see previous section), unit tests and the final exam are modeled on the AP exams and are very difficult. Unit tests are given at the end of each unit and are written to encourage students to see the big picture. Unit tests will be divided into multiple choice and free response sections. Free response problems on unit tests will involve combining material from previous units. Weighting of Class Work Grade: The class work portion of the grade will be weighted as follows: Homework and Quizzes (20%), Labs (20%), Unit Tests (60%) Final Exam: A final examination will be administered at the termination of each semester and will be cumulative. The final exam will count for 20% of the semester grade. Grading: Final grades for the quarter and semester will be assigned according to the following scale: A (90-100%), B ( %), C ( %), D ( %), F (<60%) 3

4 Lab Report Guidelines Students are required to complete written lab reports to be compiled in a lab portfolio. A general description of laboratory report requirements is provided below. Title: Short and precise; should accurately depict experiment done. Purpose: Give a rational explanation as to why you are conducting the experiment. Hypothesis: State your hypothesis. This should be an educated guess as to what you believe your investigation will show. Theoretical Background: Provide a summary of the relationships, including mathematical equations, which are relevant to the experiment. Materials and Equipment: Provide a concise list of any materials and equipment that is needed to carry out the experiment. Procedure: Give a detailed step-by-step description of how this experiment was conducted. Another scientist should be able to perform your lab using your method. The procedure should include figures that are labeled with the specific quantities that you need to measure. For example, in an experiment involving a ramp, draw the ramp and label the height and angle above horizontal. Figures should NOT be cute images copied from the web, but should be your OWN, hand-drawn or computer drawn figures. Data: Data table (Produce a labeled table of your results, including units of measurements). Calculations show any calculations that you used in the interpretation o your data. Graphs provide any labeled with units, suitably scaled graphs to help with the data you collected. Diagrams provide relevant diagrams, correctly labeled. It is especially important to include force diagrams if appropriate. Analysis: Summarize data trends give a brief explanation of the observations, trends/links in the results. Explain how errors could have occurred during the experiment and what steps could be taken to minimize their effects. If necessary, provide a statistical analysis of the accuracy of your data. Please avoid using the term human error, which is imprecise and lacking in specificity. Conclusion: Give a full, but concise explanation of the outcome of your experiment, noting if the purpose was fulfilled using this procedure. Was your hypothesis validated why or why not? Cite specific results! 4

5 Electricity and Magnetism Labs Students will spend at least 20% of course time on laboratory work and sometimes more depending on the unit. This work will include both informal activities of an exploratory nature, and also lengthier laboratory investigations requiring a formal analysis and write-up. Activities are hands-on in nature. In many laboratories, students will be encouraged to develop their own procedures and methods of inquiry. The following laboratory investigations will support the electricity and magnetism curriculum: Topographic Mapping Lab: Students use water levels around a plastic mountain model to draw the topographic lines for the mountain. They are then asked questions to prepare them for similar concepts on lines of equipotential, gradient and electric fields. Electric Potential Mapping Lab: Using conductive ink pens, students will create and test a variety of conductive patterns on a sheet of resistive paper. They will use a voltage probe to measure the magnitude and sign of the electric potential at a variety of key locations. They will use their results to sketch equipotential surfaces and to determine electric fields around the conductors. Charging and Discharging a Capacitor Lab: Students will construct a basic resistor and capacitor DC circuit using breadboards with stock capacitors and resistors. They will use a Pasco voltage probe to measure the voltage across the capacitor as a function of time for both charging and discharging cases. For long time-constant circuits (5-30 seconds,) students will obtain a single voltage-time dataset. For short time-constant circuits (<1 second) students will use the voltage probe in oscilloscope mode to again determine time constant based on percent charge or discharge. Home-built Capacitor lab: Students will construct a capacitor from paper and aluminum foil. They will determine the time constant by using a function generator and Pasco voltage probe. Combining Capacitors in Series and Parallel Lab: Students will construct a variety of series, parallel and combination circuits involving capacitors. They will use a digital multimeter to measure voltage drops across capacitors in these networks, and will compare their results to theoretical predictions. Resistivity of a Slinky Lab: In this lab students will investigate the relationship between the resistance and length of a toy Slinky. They will use a digital ohmmeter to determine resistance as a function of the number of coils. Ohmic Material Lab: Students will make a series of measurements of current versus applied voltage for a light-bulb filament in order to determine if the filament displays ohmic behavior. They will construct a graph of current versus voltage and will use it to justify their conclusion. They will correctly discuss the behavior in terms of the increase of resistance with temperature in most metals. Internal Resistance Lab: Students will use a battery in combination with a low-resistance, high-power resistor in order to determine the internal resistance of the battery. In this lab, students will be required to demonstrate proper usage of both a voltmeter an ammeter. 5

6 Series and Parallel Circuits Lab: Students will construct series circuits, parallel circuits and combination networks using a set of stock carbon resistors on a prototyping breadboard. They will measure voltage drops across resistors, current through resistors, and equivalent resistance of networks, using a standard digital multimeter probe (acts as voltmeter, ammeter and ohmmeter.) DC Motor Lab: Students will apply principles of force acting on a current loop in a uniform magnetic field to design, construct and test a simple DC motor, using a battery, length of insulated wire, and small permanent magnet. Student motors will have a 50% duty cycle, achieved by using a permanent marker to shut off current for half of a turn. Helmholtz Coil Lab: Students will construct Helmholtz coils using wire and cardboard discs. They will use a Hall probe to measure the magnetic field along the axis of these coils when a DC current is applied, comparing field magnitudes and directions to theoretical predictions. Slinky Solenoid Lab: Students will use a Hall probe to measure the magnitude and direction of the magnetic field generated within a toy Slinky. They test the relationship between field strength and the number of coils per unit length. They will also determine the permeability constant. Induction Lab: Students will explore a variety of concepts relating to Faraday s law, and electromagnetic induction by exploring stations at which they investigate how changing magnetic fields induce EMFs. They will use Lenz s law to predict the direction of the flow of induced current when a bar magnet is moved into and out of a solenoid, comparing these results to the current induced in a neighboring solenoid that is hooked up to a power supply. Students will also explore magnetic braking by analyzing the motion of a magnet dropped through a copper tube, and will investigate the repulsion of an aluminum ring when placed over a changing field core. RL Circuit Lab: Students use a signal generator to generate a positive square-wave voltage supply. They then use a Pasco voltage sensor to measure the varying voltage across the resistor of an RL circuit. By doing this they can analyze the time constant of the circuit. 6

7 Units of Study, Detailed Outline Electricity and Magnetism Unit 1: Electrostatics: Charge, Field and Energy (15 days), Chapters o Electric charge and Coulomb s law Describe types and behavior of electric charge Apply Coulomb s law and the superposition principle o Electric field Define in terms of force on a test charge Calculate magnitude and direction of field from or more point charges Interpret electric field diagrams Analyze kinematics of motion of a charged particle in a field. o Gauss s law Concept of flux and Gaussian surface Electric field by integration for symmetric geometries o Electric potential Concept of electric potential and relation to field Potential of point charge configurations Potential by integration o Fields and potentials of other charge distributions Equipotential lines and surfaces Unit 2: Conductors, Capacitors and Dielectrics (5 days), Chapter 24 o Conductors Explain how charge distributes itself on conductor in equilibrium Describe the electric fields surrounding conductors in equilibrium o Capacitors Define capacitance and state relation to charge, voltage and energy o Parallel plate capacitors o Dielectrics Understand effect of dielectric placed within a capacitor Unit 3: Electric Circuits (16 days), Chapters 25, 26 o Current, resistance and power Concept of resistance and current at microscopic level Ohm s law o Steady-state direct current circuits with batteries and resistors only Series and parallel combinations of resistors Application of Kirchoff s rules to solve circuits o Capacitors in circuits Concept of voltage and charge across capacitors in initial and steady-state situations Capacitors in series and parallel Write expressions for time-dependence of charge and voltage for capacitor 7

8 Unit 4: Magnetic Fields (15 days), Chapters 27, 28 o Forces on moving charges in magnetic fields Describe magnitude and direction of force on charges moving in magnetic fields Understand situations involving motion of charged particle through a magnetic field at constant velocity, uniform circular motion, etc. o Forces on current-carrying wires in magnetic fields Describe magnitude and direction of force on current-carrying wire in magnetic field Calculate magnitude and direction of torque on current loops o Fields of long current-carrying wires Calculate net field from multiple current sources, and the effect that one wire has on another. o Biot-Savart law and Ampere s law Derive and apply expression for the field created by summing small current elements, in particular for a circular loop of current. Use Ampere s law, plus symmetry arguments and the right-hand rule, to relate magnetic field strength to current for planar or cylindrical symmetries. Unit 5: Electromagnetism (14 days), Chapters 29, 30 o Electromagnetic induction Calculate flux of a uniform field through a loop of arbitrary orientation. Calculate flux of a non-uniform field by integration Calculate the magnitude and direction of an induced emf in a loop under different circumstances o Inductance Understand how an emf generated within an inductor Understand self-inductance of long solenoid. Understand LR and LC circuits with direct current, especially initial and steady state behavior. o Maxwell s Equations Recognize each of Maxwell s equations and identify its implications 8