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Learner’s Activity Sheet, Science (Quarter II – Week 8), Name: _____________________________________ Grade and Section: _______________, Teacher: ___________________________________ Date: _____________________________, School: _________________________________________________________________________, Dear Learner,, Good day!, In this week, you will learn to explain the operation of a simple electric motor, and generator S10FE-IIj-54, Specifically, you will learn the following to:, 1. explain the operation of a generator and electric motor; and, 2. compare and contrast electric motor and generator., In this lesson, taking good care of one’s body is being integrated., Your Teacher, , Simple Electric Motor and Generator, Activity 1, , Instructions: Below are objects normally found at home. List down, which has an electric motor. Mark (√) if the object has an electric, motor and (X) if the object has no electric motor. First object has done, for you. (12 points), , 1, , 10

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Activity 2, , Instructions: Answer the following questions briefly. (5 points), , 1. What are those materials with electric motors?, ___________________________________________________________________________, 2. What are those materials which do not have electric motors?, ___________________________________________________________________________, 3. Describe the materials with electric motors., ___________________________________________________________________________, 4. Describe the materials without electric motors., ___________________________________________________________________________, 5. What do you think is the role of the electric motor in the, materials/appliances?, ___________________________________________________________________________, , Activity 3, , Instructions: Please practice your writing skills by, copying this on your notebook, , What is a generator?, ➢ A generator converts Mechanical Energy to Electrical Energy., ➢ It produces an electric current when a coil of wire is wrapped around, an iron core and rotated near a magnet., , 2

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How does a generator work?, ➢ An electric generator is a device that converts mechanical energy, obtained from an external source into electrical energy as the output., Principle of Electromagnetic Induction in Generator, ➢ Modern generators can be attributed to Michael Faraday’s principle of, ELECTROMAGNETIC INDUCTION. Faraday discovered that when a, conductor moves in a magnetic field, electrical charges could be, created and directed to create a flow of current, ➢ At its most basic, an electrical generator is nothing more than an, electromagnet – moving wire near a magnet to direct the flow of, electricity. It’s similar to how a pump pushes water through a pipe., ➢ It is important to understand that a generator does not actually “create”, electrical energy. Instead, it uses the mechanical energy supplied to it to, force the movement of electric charges present in the wire of its windings, through an external electric circuit., ➢ This flow of electric charges constitutes the output electric current supplied, by the generator. This mechanism can be understood by considering the, generator to be similar to a water pump, which causes the flow of water but, does not actually create the water flowing through it., , How water, wind, and steam make electricity through generator?, 1. Water – Hydropower plants capture the energy of falling water to generate, electricity. A turbine converts the kinetic energy of the falling water into, mechanical energy. Then a generator converts the mechanical energy from, the turbine into electrical energy., 2. Wind - The wind turns the blades of the windmill, known as the turbine,, which, in turn, spins the shaft that turns the coil inside the magnet, known, as the generator, and it produces the electricity., 3. Fossil Fuel/Steam/Heat - Oil is burned to heat water which makes, steam. Steam moves the turbine blades that turn a shaft inside the, generator. The shaft spins the coil of wire inside a magnet in the generator, that produces a current of electricity., What are the main components of a DC generator?, A DC generator is an electrical machine which converts mechanical energy, into direct current electricity., 1. Stator - The main function of the stator is to provide magnetic fields, where the coil spins. A stator includes two magnets with opposite polarity, facing each other. These magnets are located to fit in the region of the rotor., , 3

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2. Rotor - A rotor in a DC machine, includes slotted iron laminations with, slots that are stacked to shape a, cylindrical armature core. The function of, the lamination is to decrease the loss, caused due to “Eddy Current”., 3. Commutator - A commutator works, like a rectifier that changes AC voltage to, DC voltage within the armature winding., It is designed with a copper segment, and, each copper segment is protected from, each other with the help of mica sheets. It, is located on the shaft of the machine., , Hydraulic turbine and electrical generator, cutaway view on commons.wikemedia.org from, https://commons.wikimedia.org/wiki/File:Water_turbine_(en_2).svg, , 4. Brushes – The Brushes are in constant contact with the commutator and, are attached to the wires leading from the generator. The commutator spins, while the brushes remain stationary, transferring current from the, commutator., 5. Shaft – The shaft transfers mechanical energy to the generator and turns, the coil through the magnetic field. The shaft may be turned by a turbine, that operates with water, steam or air, or by other means., Difference between the AC Generator and the DC Generator, ➢ AC generator produces AC electrical power whereas DC generator, produces DC electrical power, ➢ In DC generator the current flows in one direction whereas in the AC, generators current reverses periodically., ➢ In DC generator split rings are used they wear out quickly in AC, generator slip rings are used, so they have high efficiency., ➢ AC generators are used for small domestic applications whereas DC, generators used to power large motors., What are the top Uses of Generator?, ➢, ➢, ➢, ➢, ➢, ➢, ➢, , Back -Up power for your house, Stand-by power for businesses, Temporary power in a construction site, Permanent power to a farm, Helping main source of electricity to supply the total power required, Pop concerts, events, and exhibitions, Caravans/Camping in remote locations Outdoor catering facilities, , 4

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What is an electric motor?, , ELECTRIC MOTOR, Anything that changes electricity into motion, meaning electrical energy into, mechanical energy is called an electric motor., Basic Principles, ➢ Danish physicist HANS CHRISTIAN ØRSTED began a new scientific, era when he discovered that electricity and magnetism are linked. He, showed by experiment that an electric current flowing through a wire, could move a nearby magnet., ➢ The discovery of ELECTROMAGNETISM set the stage for the eventual, development of our modern technology-based world., How do Electric Motors work?, Motors work through the principles of ELECTROMAGNETISM. If you run, electricity through a wire, it creates a magnetic field. If you coil the wire, around a rod and run electricity through the wire, it creates a magnetic field, around the rod. One end of the rod will have a north magnetic pole and the, other will have a south pole. Opposite poles attract one another, like poles, repel. When you surround that rod with other magnets, the rod will rotate, from the attractive and repulsive forces., , 5

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Figure 2: “Parts of the Electric Motor” illustrated by Richard C. Paragas, , A. THE STATOR, Every electric motor has two essential parts; one stationary, and one that, rotates. The stationary part is the stator. Though configurations vary, the, stator is most often a permanent magnet or row of magnets lining the edge, of the motor casing, which is usually a round plastic drum., B. THE ROTOR, Inserted into the stator is the rotor, usually consisting of copper wire wound, into a coil around an axle. When electric current flows through the coil, the, resulting magnetic field pushes against the field created by the stator, and, makes the axle spin., C. THE COMMUTATOR, 1. BASICS – An electric motor has another important component, the, commutator, which sits at one end of the coil. It is a metal ring divided into, two halves. It reverses the electrical current in the coil each time the coil, rotates half a turn. The commutator periodically reverses the current, between the rotor and the external circuit, or the battery. This ensures that, the ends of coils do not move in opposite directions, and ensures that the, axle spins in one direction., 2. MAGNETIC POLES – BRUSHES AND TERMINALS. At one end of the motor, are the brushes and the terminals. They are at the opposite end from where, the rotor exits the motor casing. The brushes send electrical current to the, commutator and are typically made of graphite. The terminals are the, locations where the battery attaches to the motor and sends the currents to, spin the rotor., Difference between the AC Motor and the DC Motor, ➢ In the AC Motor, the source of power is AC mains supply whereas in, DC motor power is obtained from batteries., ➢ In AC motors no commutators and brushes are used whereas in DC, motors these play an important part in their operation., , 6

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➢ In AC motors the armature is stationary and the magnetic field rotates, whereas in DC motors it is vice versa., ➢ AC motors are suitable for large industrial applications whereas DC, motors are suitable for domestic applications., APPLICATIONS OF ELECTRIC MOTOR, ➢ Electric motors are extremely important in modern-day life. They are, used in food processors, vacuum cleaners, dishwashers, computer, printers, fax machines, video recorders, machine tools, printing, presses, automobiles, subway systems, sewage treatment plants, and, water pumping stations, to mention only a few applications., Comparison of Motor and Generator, A motor and generator perform opposite functions, but their fundamental, structure is the same. Their structure is a “coil mounted on an axle within, a magnetic field”. An electric motor is used to produce rotational motion, from electrical supply. In a motor, an electric current is passed through the, coil. The coil then creates a magnetic field that interacts with the already, existing magnetic field. This interaction forces the coil to rotate., For a motor, the input energy is electrical energy and the useful output, energy is mechanical energy., The generator is used to produce an electric current from rotational motion, (on large scale power stations a “turbine” is used to provide this rotation)., In a generator, the rotation causes the coil to rotate inside the magnetic, field. This induces an alternating current in the coil., For generator the input energy is mechanical energy and the useful, output energy is electrical energy., In power stations, it is usually the magnet which is attached to the axel and, rotates with the coils surrounding the magnet. However, the end result is, the same., The motor and the generator are almost similar from the construction point, of view, as both have stator and rotor., The differences between Motor and Generator are as follows:, The motor converts electric energy into mechanical energy, whereas,, generator does the opposite., ➢ Electricity is used in the motor, but the generator produces the, electricity., ➢ An example of motor is an electric car or bike where electric current is, supplied to the machine or device and it gets converted to mechanical, motion and, as a result, the car or bike moves. The example of, generator is that in power stations, the turbine is used as a device, which converts mechanical energy from the force of water falling from, the dam to generate electric energy., ➢, , 7

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Activity 4, 4.1 Instructions: Compare and contrast the electric motor and Generator, using the Venn diagram. Choose the answer form the box below. (10 points), , 4.2 Instructions: Read each question carefully. Choose the letter of the, correct answer. Write the letter on the space provided before the number., (10 points), _____ 1. Which of the following principles explains how an electric motors, works?, A. magnetic force, C. electrolysis, B. magnetism, D. electromagnetism, _____ 2. Which is NOT a distinguishing feature of an electric generator?, A. Electric generator converts mechanical energy into electrical., B. Electric generator converts electrical energy into mechanical, energy., C. It generates electricity., D. It is based on the principle of electromagnetic induction., _____ 3. What do we call a device that converts electricity into mechanical, movement?, A. electric charge, C. electric current, B. electric motor, D. electric generator, , 8

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_____ 4. What do you call a device that converts mechanical movement into, electricity?, A. electric field, C. electric generator, B. electric motor, D. electric plasma, _____ 5. Which of the following situations illustrate how a simple electric, motor works?, A. The energy stored in the car’s batteries is converted into the, rotation of the wheels., B. Electrical energy turned into rotation of the blades in the food, processor and cut up food., C. Both A and B, D. None of these, _____ 6. Which of the following is a device that converts electrical energy into, mechanical energy?, A. vacuum cleaner, C. weighing scale, B. bicycle, D. all of the above, _____ 7. What two forces are required for generators and electric motors to, work?, A. magnetic and thermal, C. electric and thermal, B. magnetic and radiant, D. electric and magnetic, _____ 8. What would happen to the coiled wire in an electric motor model if, there is a repulsion and attraction of the magnetic poles?, A. The coil fluctuates and converts electrical energy into chemical energy., B. The coil stops and changes mechanical energy into electrical energy., C. The coil rotates and changes electrical energy into mechanical energy., D. The coil remains stable., ____ 9. What do you call a huge wheel that rotates when pushed by water,, wind, or steam (associated with generators)?, A. Turbine, B. Magnet, C. Motor, D. Pipe, _____ 10. What do you call a devise that produces an electric current when a, coil of wire is wrapped around an iron core and rotated near a magnet?, A. magnet, B. car, C. generator, D. motor, Activity 5, Instructions: Let us make our own and simple electric motor at home., Reminder: seek assistance from adults., DIY Electric Motor, Materials:, • D battery, • Insulated 22G wire, • 2 large-eyed, long, metal sewing needles (the, eyes must be large enough to fit the wire through), • Modeling clay, • Electrical tape, • Hobby knife or cutter, • Small circular magnet, • Thin marker, , 9

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Procedures:, 1. Starting in the center of the wire, wrap the wire tightly and neatly, around the marker 30 times., 2. Slide the coil you made off of the marker., 3. Wrap each loose end of the wire around the coil a few times to hold it, together, then point the wires away from the loop, as shown:, , 4. Ask an adult to use the hobby knife or cutter to help you remove the, top-half of the wire insulation on each free end of the coil. The exposed, wire should be facing the same direction on both sides., , 5. Thread each loose end of the wire coil through the large eye of a needle., Try to keep the coil as straight as possible without bending the wire, ends., , 6. Lay the D battery sideways on a flat, surface., 7. Stick some modeling clay on either, side of the battery so it does not roll, away., 8. Take 2 small balls of modeling clay, and cover the sharp ends of the, needle., 9. Place the needles upright next to the, terminals of each battery so that the, side of each needle touches one, terminal of the battery., , 10

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10. Use electrical tape to secure the, needles to the ends of the battery., Your coil should be hanging above, the battery., 11. Tape the small magnet to the side, of the battery so that it is centered, underneath the coil., 12. Give your coil a spin., , References:, 1. K to 12 Most Essential Learning Competencies, 2. Science – Grade 10, Learner’s Material, First Edition 2015, , 3. Science – Grade 10, Alternative Delivery Mode, Quarter 2 – Module 5: Simple Electric Motor and Generator, First Edition, 2019, , 4. Emerlinda P. Cerna, Science– Grade 10, Alternative Delivery Mode, Quarter 2 – Module 6: How a Simple Electric Motor and Generator, Operates, First Edition, 2020, , CERTIFICATION, , This is to certify that my child has successfully done all the, activities included in this Learning Activity Sheet., _________________________________________, Name and Signature of the Parent, , 11, , ____________________, Date