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Draw a diagram that shows the magnetic fields that result when like poles of two magnets are close to each other when unlike poles are close. Use lines to show the magnetic fields that result from these situations. Warm Up: Current Can Produce Magnetism Now, you will learn Before, you learned Electric current is the flow of charge Magnetism is a force exerted by magnets Magnets attract or repel other magnets How an electric current can produce a magnetic field How electromagnets are used How motors use electromagnets Electromagnetism Electromagnetism – magnetism that results from an electric current. When a charged particle moves, it produces a magnetic field. Because an electric current consists of moving electrons, a current in a wire produces a magnetic field. Increasing the amount of current in the wire increases the strength of the magnetic field. Magnetic Field of a Wire The direction of current Determines the direction Of the magnetic field Electromagnetism How is a coil of wire that carries a current similar to a bar magnet? Electromagnet A magnet made by placing a piece of iron or steel inside a coil of wire. As long as the coil carries a current, the metal acts as a magnet and increases the magnetic field of the coil. When the current is turned off, the magnetic domains in the metal become random again and the magnetic field disappears. Electromagnet By increasing the number of loops in the coil, you can increase the strength of the electromagnet. Uses of Electromagnets Electromagnets can be turned on and off, and have more uses than permanent magnets. Electromagnets store information on a computer Electromagnets pick up and dumb recycling at a dump Magnetic strips of credit cards Motors Review 1. Explain how electric current and magnetism are related. 2. Describe three uses of an electromagnet 3. How does an electromagnet differ from a permanent magnet? Fill in the blanks with words from the box. cars fans magnetic coils generator motor currents hydroelectric spins electromagnetism kinetic turbine Magnetism and electricity are connected in a way that is very useful to people. Magnetic fields can be used to generate electric _________________ and electric currents can be used to generate _________________ fields. This connection between magnets and electricity is called _________________. How does this work? As Hydroelectric generators convert the kinetic energy of water flowing downhill into electricity. a_________________ of wire spins in a magnetic _________________, a current flows through it. A device that uses a coil of spinning wires in a magnetic field to make electricity is called a _________________. A _________________ power plant, for example, uses the energy of flowing water to generate electricity. As water flows from a high place to a low place, it pushes on _________________ blades causing them to spin. Coils of wire are attached to the spinning turbine and placed next to magnets. As the coil _________________ in the magnetic field, electric current flows through the wires. In short, the _________________ energy of water is transformed into electrical energy. This process can be reversed to produce an electric _________________. An electric current through a coil of wires in a magnetic field will cause the coil to start spinning. This coil is attached to an axle, which can be used to move something else such as a wheel or a blade. _________________ and toy cars are examples of devices that use an electric motor to generate motion.