NAME:__________________________________________ GRADE/SECTION:______________________________ 12 GENERAL PHYSICS 2 Semester II – Week 8 Magnetic Induction CONTEXTUALIZED LEARNING ACTIVITY SHEETS SCHOOLS DIVISION OF PUERTO PRINCESA CITY General Physics II – Grade 12 Contextualized Learning Activity Sheets (CLAS) Semester II - Week 8: Magnetic Induction First Edition, 2020 Republic Act 8293, Section 176 states that: No copyright shall subsist in any work of the Government of the Philippines. However, prior approval of the government agency or office wherein the work is created shall be necessary for the exploitation of such work for a profit. Such agency or office may, among other things, impose as a condition the payment of royalties. Borrowed materials (i.e., songs, stories, poems, pictures, photos, brand names, trademarks, etc.) included in this CLAS are owned by their respective copyright holders. Every effort has been exerted to locate and seek permission to use these materials from their respective copyright owners. The publisher and authors do not represent nor claim ownership over them. Published by the Schools Division of Puerto Princesa City Development Team of the Contextualized Learning Activity Sheets Writer: Irene L. Labanero Content Editor: Sheryll C. Saclet Language Editor: Leonebell P. Dacuan Proofreader: Elsie M. Zabalo Reviewer: Rolando A. Taha EdD Illustrator: Irene L. Labanero Layout Artist: Carissa M. Calalin Management Team: Servillano A. Arzaga, CESO V, SDS Loida P. Adornado PhD, ASDS Cyril C. Serador PhD, CID Chief Ronald S. Brillantes, EPS-LRMS Manager Rolando A. Taha, EdD, EPS-Science Eva Joyce C. Presto, PDO II Rhea Ann A. Navilla, Librarian II Division Quality Assurance Team: Ronald S. Brillantes, Liezl O. Arosio, Carissa M. Calalin, Carmencita B. Daculap, Meguilito D. Campillos, Leslie O. Pulanco, and Llewelyn Anne M. Venturillo Division of Puerto Princesa City-Learning Resource Management Section (LRMS) Division Evaluators: Sta. MonicaLR Heights, Brgy. Sta. Monica, Puerto Princesa City Telephone No.: (048) 434 9438 Email Address: puertoprincesa@deped.gov.ph Lesson 1 Magnetic Induction MELC: Identify the factors that affect the magnitude of the induced emf and the magnitude and direction of the induced current (Faraday’s Law) (STEM_GP12EM-IVa-1). Compare and contrast electrostatic electric field and non-electrostatic/induced electric field (STEM_GP12EM-IVa-3). Calculate the induced emf in a closed loop due to a time-varying magnetic flux using Faraday’s Law (STEM_GP12EM-IVa-4). Describe the direction of the induced electric field, magnetic field, and current on a conducting/nonconducting loop using Lenz’s Law (STEM_GP12EM-IVa-5). Compare and contrast alternating current (AC) and direct current (DC) (STEM_GP12EM-IVb-6). Characterize the properties (stored energy and time-dependence of charges, currents, and voltages) of an LC circuit (STEM_GP12EM-IVb-8). Objectives: 1. Cite the factors that affect the magnitude of the induced emf and induced current. 2. Differentiate electrostatic electric field and induced electric field. 3. Determine the induced emf in some physics problems using Faraday’s law. 4. Explain the direction of the induced electric field, magnetic field, and current using Lenz’s law. 5. Differentiate alternating current and direct current. 6. Distinguish the properties of an LC circuit. Let’s Try Directions: Read each question carefully. Write the letter of the correct answer on the space provided before the number. ______ 1. The north pole of a magnet approaches a coil that causes its magnetic flux to increase. Given this scenario, what will be the direction of the induced current? A. Clockwise C. Down B. Counter-clockwise D. Up ______ 2. A wire loop is being pulled through a uniform magnetic field. What is the direction of the induced current? A. Clockwise C. Down B. Counter-clockwise D. No induced-current ______ 3. When a double loop of wire is used, the kick on the millivoltmeter is twice as large as before. A triple loop induces three times the emf and so on. Which of the following can be deduced from this statement? A. The emf is proportional to the number of turns in a coil. B. The speed at which the conductor moves increases the current. C. The induced emf is directly proportional to the current in the system. D. The coil brought changes in magnetic field, thus changes the emf and current. 3 ______ 4. How does an alternating current differ from a direct current? A. AC is a current that changes while DC is steady. B. AC is unidirectional on the other hand DC is bidirectional. C. AC has no polarity but DC has positive and negative polarity. D. AC contains a single path on the other hand DC contains back and forth movement of the electron. ______ 5. In an LC Circuit, the charge on the capacitor and the current on the inductor varies sinusoidally with time. If there are no energy losses, what will happen to the charges in the capacitor? A. It decreases the voltage. B. It increases the current. C. It oscillates back and forth indefinitely. D. It travels in unidirectional along with the path in the circuit. ______ 6. A varying magnetic field linking a loop or coil causes an emf within the conductor – an induced current. This induced current is the displacement of charges of an electric force due to the existence of ____________. A. Electrostatic electric field C. Nonelectrostatic electric field B. Magnetic Force D. All of these ______ 7. How will you differentiate an electrostatic electric field from nonelectrostatic or induced electric field? A. Electrostatic electric field is nonconservative while nonelectrostatic field is conservative. B. Electrostatic electric field does net work on moving charge but nonelectrostatic electric field does no work. C. Electrostatic electric field is determined via Faraday’s law on the other hand Coulomb’s law applies in induced electric field. D. An electrostatic electric field is produced by static distribution of charge while induced electric field is produced by a changing magnetic field. ______ 8. Which of the following are factors that affect the magnitude and direction of induced current? I. Mass of the load II. Length of the conductor III. Strength of the magnetic field IV. Number of the loops in the coil A. I and II C. I,II, and III B. II and IV D. II, III, and IV ______ 9. A bar magnet approaches a single coil of area 1.73 x 10-2 m2 and makes the average value of B cos θ to decrease from 0.38 T to 0.079 T in 0.17 seconds. What is the magnitude of the induced emf? A. 0.056 V C. 0.14 V B. 0.031 V D. 1.17 V ______ 10. (Refer to situation no. 9). What will be the induced emf if there are 127 loops in the coil? A. 7.11 V C. 17.78 V B. 3.94 V D. 148.59 V 4 Let’s Explore and Discover Unlocking of Difficulties Electromagnetism - A branch of Physics that deals with the electromagnetic force that occurs between electrically charged particles. Induction - Generation of an electric current by a varying magnetic field. Michael Faraday is best known for his contribution to electromagnetism. Being born in poor family and only receiving a basic formal education did not limit him to excel in the field of Science. He was the first scientist to produce an electric current from a magnetic field and invented the first electric motor and dynamo. His experiments significantly paved the way for our understanding of electromagnetism. Have you experienced going to the supermarket and noticed that you are cashless and pay using a card? Or have you witnessed someone withdrawing cash using an Automated Teller Machine (ATM)? Have you asked how swiping or scanning the card can deduct money? Have you wondered how it works? The answer to these questions lies on the idea of “electromagnetic induction” and thanks to Michael Faraday for his great contribution to this field. Michael Faraday (1791 - 1867) (Source: roberthuffstutter , MICHAEL FARADAY, https://creativecommons.org/licenses/by-nc/2.0/. licensed with CC BY-NC 2.0.) After Hans Christian Oersted demonstrated that electric currents can produce magnetic fields, another physicist in the person of Michael Faraday established a law where electromotive force (emf) is produced from the interaction of magnetic field and electric current (electromagnetic induction). This law is known as Faraday’s law. Several factors can affect the emf induced by magnetic flux such as the change in the magnetic flux, since emf depends on the loop’s area and angle. Also, the emf is greatest when the change in time is smallest, thus the speed at which the conductor moves is also considered. In addition, the number of turns in a coil is also a factor that can affect the induced emf. Based on that, the following relationships are formulated: 1. Emf is directly proportional to the change in magnetic flux. 2. Emf is inversely proportional to the change in time. 3. Emf is directly proportional to the number of turns of a coil. 5 Furthermore, Faraday’s law also implies that a changing magnetic field induces an emf when it interacts in an electric circuit, therefore work is done on the conduction of electrons in the wire. The source of this work is the electric field that is induced in the wires. It is important to note the difference between the electrostatic electric field and nonelectrostatic or induced electric field. Electrostatic electric field is determined by Coulomb’s law, it is conservative and does no work over a closed path, on the other hand, induced electric field is nonconservative since it does net work in moving a charge over a closed path. In formula, Faraday’s law of magnetic induction is given by: ٤ = induced voltage (electromotive force) N = number of turns ∆Φ = change in magnetic flux ∆t = change in time The unit for emf is volts (V) and the negative sign (-) indicates that the emf creates a current (I) and magnetic field (B) that oppose the change in flux (∆Φ). This principle is known as Lenz’s law after the Russian physicist Heinrich Lenz. Lenz’s law is used to predict the direction of an emf induced in a loop or coil of wire by the changing magnetic field. (Source: Keministi , “Lenz law demonstration.png" http://creativecommons.org /publicdomain/zero/1.0/deed.en , marked under CC0 1.0. ). 6 To use Lenz’s law to determine the directions of the induced magnetic fields, currents, and emfs, follow this problem-solving strategy: 1. Make a sketch of the situation for visualizing and recording directions. 2. Determine the direction of the magnetic field B. 3. Determine whether the flux is increasing or decreasing. 4. Now determine the direction of the induced magnetic field B. It opposes the change in flux by adding or subtracting from the original field. 5. Use Right Hand Rule-2 to determine the direction of the induced current I that is responsible for the induced magnetic field B. 6. The direction (or polarity) of the induced emf will now drive a current in this direction and can be represented as current emerging from the positive terminal of the emf and returning to its negative terminal. (Source: “Faraday’s Law of Induction: Lenz’s Law,” Lumen Boundless Physics, accessed March 24, 2021, https://courses.lumenlearning.com/austinccphysics2/chapter/23-2-faradays-law-of-induction-lenzs-law/.) The changing magnetic flux through the coil induces an emf, thus producing a current. The induced current produces its own magnetic field. If the number of field lines or magnetic field increases, the magnetic flux also increases. Following the Lenz’s law, the induced emf creates its own current and magnetic field that opposes the change in magnetic flux. When there is no change in magnetic flux, there will be no emf or current that is induced in the loop. Thought to Ponder: Induced emf occurs when there’s a change in the magnetic flux. If the flux in the circuit has a constant value, there is no induced emf. Sample Problem 1.a. Study the illustrations below. In which direction is the current induced on the loop directed? In figure A, the magnetic field lines point out from the North pole of the magnet, the magnetic flux in the loop increases due to the increasing number of magnetic field lines. To oppose this change, the current in the loop will be induced in the counter-clockwise direction with respect to the bar magnet. In figure B, the approaching South pole will induce a current that is in clockwise with respect to the direction bar magnet. The flux in the loop increases because of the increase in the number of field lines. Using Lenz’s law, the magnetic field line induced by the current is directed from the front to the back. 7 Sample problem 1.b. A bar magnet approaches a single coil with a radius of 7.42 cm and the average value of B cos θ increases from 0.079 Tesla (T) to 0.38 T in 0.17 s. Find a.) The rate of change in the flux in Weber per second (Wb/s). (b.) The emf and current in Amperes (A) induced if the coil has a total resistance of 100 Ohms (Ω). (c.) The emf induced if the coil contains 50 loops (d.) the direction of the induced current and magnetic field. Follow these steps in solving problems: 1st : Write all of the given data needed in the solution. 2nd: Write the unknown or the information the problem is seeking to solve. rd 3 : Write the formula and perform a derivation if necessary. 4th: Calculate. 5th: Write your final answer. 6th: Formulate a conclusion. Illustration Given: Unknown: Radius of the coil Average value of initial B cos θ Average value of final B cos θ Change in time Total resistance r = 7.42 cm = 0.0742 m B cos θi = 0.079 T B cos θf = 0.38 T ∆T = 0.17 s R =100 Ω Formula: a.) The rate of change in the flux b.) The emf and current induced c.) The emf induced if the coil contains 50 loops d.) The direction of the induced current and magnetic field Faraday’s and Lenz’s laws Calculate: a.) Magnetic flux Φ = ABcosθ Area of the coil = Πr2 = 3.1415(0.0742m)2 A = 0.0173 m2 ∆Φ = A B cos θf - A B cos θi = A (0. 38 T - 0.079 T) = A (0.301 T) = (0.0173 m2) (0.301 T) ∆Φ = 5.21 x 10-3 Wb Rate of change in the flux = ∆Φ ∆T = 5.21 x 10-3 Wb 0.17 s Rate of change in the flux = 0.031 Wb/s 8 b.) = - 1 (0.031 Wb/s) ٤ = - 0.031 V c.) = - 50 (0.031 Wb/s) = - 1.55 V Answer: a.) 0.031 Wb/s b.) ٤ = - 0.031 V , I = 3.1 x 10-4 A c.) - 1.55 V d.) Following the Lenz’s law, the magnetic field lines point out from the north pole of the magnet, the magnetic flux in the loop increases. To oppose this change, the current in the loop will be induced in the counter-clockwise direction with respect to the bar magnet and the induced magnetic field will be on the opposite direction of the magnetic field, and that is from back to front. Conclusion: a.) The rate of change in the flux is 0.031 Wb/s. b.) The emf induced has the value of 0.031 V. c.) The emf induced if the coil contains 50 loops is 1.55 V. d.) The direction of the induced current is counter clockwise and the induced magnetic field is from the back to the front. Alternating Current and Direct Current Direct current (DC) and alternating current (AC) both describe the types of current flow in a circuit. Direct current refers to the flow of electric charge in only one direction and the source voltage is constant, thus the magnitude does not change, on the other hand, alternating current reverses the direction of the flow of the electric charge. The electric charge can move either forward or backward, also the magnitude and polarity change along with time. Further comparison of AC and DC is stated in the following table. Basis Definition Alternating current The direction of the current reverses periodically. Causes of flow of electrons Rotating a coil in a uniform magnetic field or rotating a uniform magnetic field within a stationary coil 50 or 60 Hertz depends on the country Bidirectional Frequency Direction of flow of electrons. Power factor Lies between 0 and 1 Direct current The direction of the current remains the same. Constant magnetic field across the wire Zero Unidirectional Always 1 9 Polarity Obtained from It has polarity (+, -) Alternators Type of load Their load is resistive, inductive, or capacitive. It is represented by irregular waves like triangular wave, square wave, square tooth wave, and sine wave. Can be transmitted over long distance with some losses. Graphical representation Transmission Convertible Easily converted into direct current Substation Few substation is required for generation and transmission. Passive parameter Hazardous Application Impedance Dangerous Factories, Industries, and for domestic purposes Do not have polarity Generators, battery, and solar cell, etc. Their load is usually resistive in nature. It is represented by the straight line. It can be transmitted over very long distance with negligible losses. Easily converted into alternating current More substations are required for generation and transmission. Resistance Very dangerous Electroplating, Electrolysis, Electronic, Equipment etc. (Source: “Difference Between Alternating Current (AC) and Direct Current (DC),” Circuitglobe.com, accessed March 28, 2021, https://circuitglobe.com/difference-between-alternating current-ac-and-direct-current-dc.Html#KeyDifferences) LC Circuit An LC circuit (inductor- capacitor circuit) is a closed loop that contains only two elements, a capacitor and an inductor. The inductor stores energy in its magnetic field while energy is stored in its electric field for the capacitor. The LC circuit shifts the energy stored in the circuit between the electric and magnetic field, thus it can oscillate even without a source of emf. If the capacitor of an LC circuit contains a charge before the switch is closed, all of the energy in the circuit will be stored in the capacitor’s electric field. The energy in the capacitor is given by: Where U is energy in the capacitor, q is the charge, and C is the capacitance of the capacitor. The capacitor begins to discharge the energy when the switch is closed, therefore producing a current in the circuit. The produced current will create a magnetic field in the inductor. This process will lead to the transfer of energy from the capacitor (electric field will diminish) to the inductor where its magnetic field increases. The current is at its maximum level value (Io) when the capacitor is completely discharged, all the energy is stored in the magnetic field of the inductor and the energy in the inductor is UL= ½ LIo2. (UL – energy in the inductor, L- inductance and Io- maximum current). Due to the absence of resistance in the circuit, there is no loss of energy, therefore, the maximum energy stored in the capacitor is equal to the maximum energy stored in the inductor is: 10 When the capacitor charge q at time t and the current is I at time t, the total energy in the circuit is: Because there is no energy dissipation, it can be written as: After reaching the maximum current (Io), the capacitor will be recharged due to the continuous transport charge between the capacitor’s plates by the current. Current will continue to flow even though the capacitor is discharged because the inductor resists a change in current, this will result for the capacitor to change with opposite polarity. The capacitor’s electric field increases while the inductor’s magnetic field diminishes. As a result, the energy from the inductor is transferred back to the capacitor. Following the law of conservation of energy, the capacitor will re-acquire its maximum charge however its plates will be charged opposite to their initial charge. When the capacitor is completely charged, it will transfer its energy again to the inductor until it becomes fully discharged. Then again, the energy flows back to the capacitor, and the initial state of the circuit is restored. (Source: Chetvorno ,Tuned circuit animation 3.gif,http://creativecommons. .org/publicdomain/zero/1.0/deed.en Marked under CCO 1.0) 11 Let’s Practice Directions: Solve the word problem below. Write your answer on the space provided. A bar magnet approaches a coil with a radius of 124 mm and the average value of B cos θ increase from 0.0043 T to 0.17 T in 0.01 s. Find the a.) emf induced in the coil; and b.) the induced emf if the coil contains 100 loops. Given: Unknown: Formula: Calculate: Answer: Conclusion: Directions: Study the figure below and answer the given question. In which direction is the induced current and magnetic field directed? Support your answer. _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ _________________________________________________________________________________________ 12 Let’s Do More Directions: Using the venn diagram below, compare and contrast alternating current (AC) and direct current (DC). Give at least 5 differences. Directions: Solve the word problem below. Write your answer on the space provided. Use additional sheet of paper if necessary. A magnet is approaching a square coil of wire with a length of 3.56 cm that contains 77 loops. The average value of Bcosθ decreases from 0.54 T to 0.0032 T in 0.13 s. What is the magnitude of the induced emf? How about the magnitude of induced current if the coil has a resistance of 75 Ω? Given: Unknown: Formula: Calculate: Answer: Conclusion: 13 Let’s Sum Up Directions: Identify whether the following statements about magnetic induction is true or false. Write T if the statement is correct and F if it is incorrect. Write your answer on the space provided before each number. ________ 1. Emf is inversely proportional to the change in magnetic flux. ________ 2. The number of loop in a coil is a factor that affects the magnitude of the induced emf, thus if the number of the loop in a coil increases, the emf also increases. ________ 3. An electrostatic electric field is conservative and does no work in a closed path while an induced electric field is nonconservative. ________ 4. Induced electric field is determined by using Coulomb’s law on the other hand an electrostatic electric field follows Faraday’s law. ________ 5. Since magnetic flux affects the induced emf, area, and angle are also factors that need to be considered. Directions: Answer the following questions on the space provided after each item. 1. What are the factors that can affect the magnitude of the induced emf and current? Cite 3 and briefly explain each. _______________________________________________________________________________________ _______________________________________________________________________________________ _______________________________________________________________________________________ _______________________________________________________________________________________ 2. How will you differentiate an electrostatic electric field and an induced electric field? _______________________________________________________________________________________ _______________________________________________________________________________________ _______________________________________________________________________________________ _______________________________________________________________________________________ 3. What are the properties of an LC circuit? How will you distinguish these properties from one another? _______________________________________________________________________________________ _______________________________________________________________________________________ _______________________________________________________________________________________ _______________________________________________________________________________________ 4. What does Faraday’s law suggest about magnetic induction? How about Lenz’s law? Briefly explain the idea regarding the two laws. _______________________________________________________________________________________ _______________________________________________________________________________________ _______________________________________________________________________________________ _______________________________________________________________________________________ _______________________________________________________________________________________ 14 _______________________________________________________________________________________ _______________________________________________________________________________________ Let’s Assess Directions: Read each question carefully. Write the letter of your answer on the space provided before the number. ______ 1.Which of the following are factors that affect the magnitude and direction of induced current? I. Mass of the load II. Length of the conductor III. Strength of the magnetic field IV. Number of the loops in the coil A. I and II C. I,II, and III B. II and IV D. II, III, and IV ______ 2. When a double loop of wire is used, the kick on the millivoltmeter is twice as large as before. A triple loop induces three times the emf and so on. Which of the following can be deduced from this statement? A. The emf is proportional to the number of turns in a coil. B. The speed at which the conductor moves increases the current. C. The induced emf is directly proportional to the current in the system. D. The coil brought changes in magnetic field, thus changes the emf and current. ______ 3. A varying magnetic field linking a loop or coil causes an emf within the conductor – an induced current. This induced current is the displacement of charges of an electric force due to the existence of ____________. A. Electrostatic electric field C. Nonelectrostatic electric field B. Magnetic Force D. All of these ______ 4. How will you differentiate an electrostatic electric field from nonelectrostatic or induced electric field? A. Electrostatic electric field is nonconservative while nonelectrostatic field is conservative. B. Electrostatic electric field does net work on moving charge but nonelectrostatic electric field does no work. C. Electrostatic electric field is determined via Faraday’s law on the other hand Coulomb’s law applies in induced electric field. D. An electrostatic electric field is produced by static distribution of charge while induced electric field is produced by a changing magnetic field. ______ 5. A bar magnet approaches a single coil of area 1.73 x 10-2 m2 and makes the average value of B cos θ to decrease from 0.38 T to 0.079 T in 0.17 seconds. What is the magnitude of the induced emf? A. 0.056 V C. 0.14 V B. 0.031 V D. 1.17 V ______ 6. (Refer to situation no. 5.) What will be the induced emf if there are 127 loops in the coil? A. 7.11 V C. 17.78 V B. 3.94 V D. 148.59 V 15 ______ 7. The north pole of a magnet approaches a coil that causes its magnetic flux to increase. Given this scenario, what will be the direction of the induced current? A. Clockwise C. Down B. Counter-clockwise D. Up ______ 8. A wire loop is being pulled through a uniform magnetic field. What is the direction of the induced current? A. Clockwise C. Down B. Counter-clockwise D. No induced-current ______ 9. How does an alternating current differ from a direct current? A. AC is a current that changes while DC is steady. B. AC is unidirectional on the other hand DC is bidirectional. C. AC has no polarity but DC has positive and negative polarity. D. AC contains a single path on the other hand DC contains back and forth movement of the electron. ______ 10. In an LC Circuit, the charge on the capacitor and the current on the inductor varies sinusoidally with time. If there are no energy losses, what will happen to the charges in the capacitor? A. It decreases the voltage. B. It increases the current. C. It oscillates back and forth indefinitely. D. It travels in unidirectional along with the path in the circuit. 16 Answer Key Let’s Try 1. B 2. D 3. A 4. A 5. C 6. C 7. D 8. C 9.B 10. B Let’s Practice Activity 1 Activity 2 1.a. Emf = -0.80 V I - clockwise with respect to 1.b. Emf = -80 V the magnet B – front to the back Let’s Do More Activity 1 Answers may vary. Refer to the table on page 10 1. F 4. F Let’s Sum Up Activity 1 Activity 2 2. T 3.T Answers may 5. T vary Activity 2 Emf = 0.404 V I = 5.39 x 10-3 A Let’s Assess 1. C 6. B 2. A 7. B 3. C 8. D 4. D 9. A 5. B 10.C References Websites Circuit Globe. “Difference Between Alternating Current (AC) and Direct Current (DC).” Accessed March 28,2021. https://circuitglobe.com/difference-between-alternating-current-ac-anddirect-current-dc.html. Lumen Boundless Physics. “Faraday’s Law of Induction: Lenz’s Law.” Accessed March 24, 2021. https://courses.lumenlearning.com/austincc-physics2/chapter/23-2-faradays-law-ofinduction-lenzs-law/. 17 FEEDBACK SLIP A. FOR THE LEARNER Thank you very much for using this CLAS. This learner’s material is aimed at ensuring your worthwhile learning through the help of your family members. For feedback purposes, kindly answer the following questions: 1. Are you happy and contented with your learning experiences using this CLAS? 2. Were you able to follow the processes and procedures that were indicated in the different learning activities? 3. Were you guided by anybody from your family while using this CLAS 4. Was there any part of this CLAS that you found difficult? If yes, please specify what it was and why. B. FOR THE PARENTS / GUARDIANS Do you have any suggestions or recommendations on how we can make improvements to this CLAS to better serve the learners? Yes (Please indicate what this is/these are.) None Contact Number: __________________________________ NAME OF SCHOOL: Teacher’s Name and Signature: Parent’s / Guardian’s Name and Signature: Date Received: Date Returned: 18 YES NO