Electricity And Magnetism Powerpoint

[Arridano Tillo]

Thisdocument provides an overview of electricity and magnetism. It discusses electric and magnetic fields, how magnetic fields are produced by electric currents, and some applications like electromagnets and motors. The key topics covered include electric charge, electric fields, magnetic fields, electromagnetism, and basic electric circuits. Hands-on activities are also included to demonstrate these concepts.Read less

Electricity and Electromagnetism. What is Electricity?. Electricity is a form of energy resulting from charged particles. What are the 2 types of electricity?. Static Electricity. Current Electricity. Current electricity is the flow of electrical charges through a path.

Using Electricity Safely EQ: How can you use electricity safely? When too many appliances are plugged into the same power source (plug), the current of electricity can increase. This current can become large enough to start fires. If you touch two power lines at the same time, or one power line and the ground it can be dangerous.

Magnetic levitation Magnetic levitation- the lifting of an object by the means of magnetic forces. Magnetic levitation happens when two like poles of magnets face each other creating a pushing force against the force of gravity.

Principles of electricity and magnetism 2 (E&M II), is the second semester in our two-semester sequence of junior-level classical electromagnetism courses for physics majors. We have compiled a suite of clicker questions, in-class activities, homework problems & other assessments, covering a range of electrodynamics topics, including:

This package of course materials also contains implementation guides, an archive of several past E&M II courses at CU, and other supporting documents (e.g., explicit learning goals, relevant education research articles, and notes on common student difficulties). Source files are included (in PowerPoint and Word formats) in order to facilitate their adaptation and implementation at other institutions.

Instructors and education researchers are free to use and adapt these materials for non-commercial purposes, according to the creative commons license below. We ask for your cooperation in not making any solutions you may create for the homework (and exam problems, clicker questions, etc...) available on the open web, out of respect for instructors and students at other institutions, and for maintaining the integrity of our research.

Engineers design electromagnets, which are a basic part of motors. Electromagnetic motors are a big part of everyday life, as well as industries and factories. We may not even realize that we interact with electromagnets on a daily basis as we use a wide variety of motors to make our lives easier. Common devices that use electromagnetic motors are: refrigerators, clothes dryers, washing machines, dishwashers, vacuum cleaners, sewing machines, garbage disposals, doorbells, computers, computer printers, clocks, fans, car starters, windshield wiper motors, electric toothbrushes, electric razors, can openers, speakers, music or tape players, etc.

The really important thing to remember today is that electricity can create a magnetic field. This may sound strange, because we're used to magnetic fields just coming from magnets, but it is really true! A wire that has electrical current running through it creates a magnetic field. In fact, the simplest electromagnet is a single wire that is coiled up and has an electric current running through it. The magnetic field generated by the coil of wire is like a regular bar magnet. If we put an iron (or nickel, cobalt, etc.) rod (perhaps a nail) through the center of the coil (see Figure 1), the rod becomes the magnet, creating a magnetic field. Where do we find the electricity for an electromagnet? Well, we can get this electricity a few ways, such as from a battery or a wall outlet.

We can make this magnetic field stronger by increasing the amount of electric current going through the wire or we can increase the number of wire wraps in the coil of the electromagnet. What do you think happens if we do both of these things? That's right! Our magnet will be even stronger!

Engineers use electromagnets when they design and build motors. Motors are in use around us everyday, so we interact with electromagnets all the time without even realizing it! Can you think of some motors that you have used? (Possible answers: Washing machine, dishwasher, can opener, garbage disposal, sewing machine, computer printer, vacuum cleaner, electric toothbrush, compact disc [CD] player, digital video disc [DVD] player, VCR tape player, computer, electric razor, an electric toy [radio-controlled vehicles, moving dolls], etc.)

Brainstorming: In small groups, have students engage in open discussion. Remind them that no idea or suggestion is "silly." All ideas should be respectfully heard. Ask the students: What is an electromagnet?

Worksheet: At the beginning of the activity, hand out the Building an Electromagnet Worksheet. Have students make drawings, record measurements and follow along with the activity on their worksheets. After students finish the worksheet, have them compare answers with a peer or another pair, giving all students time to finish. Review their answers to gauge their mastery of the subject.

Hypothesize: As students make their electromagnet, ask each group what would happen if they changed the size of their battery. How about more coils of wire around the nail? (Answer: An electromagnet can be made stronger in two ways: increasing the amount of electric current going through the wire or increasing the number of wire wraps in the coil of the electromagnet.)

Graphing Practice: Present the class with the following problems and ask students to graph their results (or the entire class' results). Discuss which variables made a bigger change in the strength of the electromagnet.

Another way to vary the current in the electromagnet is to use wires of different gauges (thickness) or of different materials (for example: copper vs. aluminum). Ask students to test different wire types to see how this affects the electromagnet's strength. As a control, keep constant the number of coils and amount of current (battery) for all wire tests. Then, based on their rest results, ask students to make guesses about the resistances of the various wires.

Students learn more about magnetism, and how magnetism and electricity are related in electromagnets. They learn the fundamentals about how simple electric motors and electromagnets work. Students also learn about hybrid gasoline-electric cars and their advantages over conventional gasoline-only-pow...

Students are briefly introduced to Maxwell's equations and their significance to phenomena associated with electricity and magnetism. Basic concepts such as current, electricity and field lines are covered and reinforced. Through multiple topics and activities, students see how electricity and magne...

Students induce EMF in a coil of wire using magnetic fields. Students review the cross product with respect to magnetic force and introduce magnetic flux, Faraday's law of Induction, Lenz's law, eddy currents, motional EMF and Induced EMF.

Students investigate the properties of magnets and how engineers use magnets in technology. Specifically, students learn about magnetic memory storage, which is the reading and writing of data information using magnets, such as in computer hard drives, zip disks and flash drives.

The contents of this digital library curriculum were developed under grants from the Fund for the Improvement of Postsecondary Education (FIPSE), U.S. Department of Education, and National Science Foundation (GK-12 grant no 0338326). However, these contents do not necessarily represent the policies of the Department of Education or National Science Foundation, and you should not assume endorsement by the federal government.

Ask the students to get into groups of three to four. Explain that 'nano' means 10-9 or one billionth of something and that dividing by 1000 can help us understand how small nano is. Use a meter stick to show that a meter is divided into 1000 mm. Explain that if you divide 1 mm by 1000, you get 1 micrometer (something that we can't see), and if you divide the micrometer into another 1000 equal spaces, each one of those would be 1 nanometer.

Ask each group to brainstorm definitions or explanations of one of the three following words: giant, magneto, resistance. After a couple minutes, ask a representative of each group to share his/her group's definition of the word.

Summarize by emphasizing that giant means the effect is very large, that the effect has something to do with magnetism, and that the resistance is related to how much electricity/current can flow through the material. GMR materials are found in read heads of computer hard drives and control the flow of current through a circuit that reads the magnetic data on the hard disk.

Describe the three parts of an atom (electrons - negative charge, protons - positive charge, neutrons - neutral). Explain that moving electrons create an electric current. Explain that some materials are conductors and are good carriers of electric current, and that some materials are insulators and are not good carriers of electric current.

Explain how to identify magnetic and non-magnetic materials. Ask the groups to answer the magnetism question in the Powerpoint slide. In order to do so, each group will need to test various materials with a cow magnet for magnetism.

Explain that current induces a magnetic field, and a that magnetic field induces an electric current. Ask the groups to answer the electricity/magnetism question in the Powerpoint slide. In order to do so, each group will need to experiment with the cow magnet and the coil/LED demo.

Explain GMR materials and what happens when a magnetic current is introduced. Explain how information is stored on the platters. (Ask GMR group for explanation.) Ask the groups to answer the GMR question. Then students can try to find the read/write head by dissecting a hard drive with a screwdriver. Show the read/write head and explain basic function in computer hard drive (Ask GMR group for explanation.)

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