I. Directions: Pick the definition in column B that best matches the word in column A. Write the letter of the definition on the blank line.

Transcription

1 1 U LY from the series lectricity and Magnetism P -. Directions: Pick the definition in column B that best matches the word in column. Write the letter of the definition on the blank line. 1. current electricity 2. circuit 3. conductor 4. insulator 5. switch 6. short circuit 7. circuit breaker B a. omething that lets electrons flow easily through it. b. an start a fire or cause other problems because electricity can escape from its path. c. omething that stops the flow of electrons. d. lectrons that are moving. e. Protects buildings from overloading circuits and fires. f. omething that can control the flow of electricity through a circuit. g. Made up of three main parts: a source of electrons, an object to use the electricity, and a path.. Directions: he following questions need a short answer. 1. Describe how a series and a parallel circuit are different from each other. 2. Why is a parallel circuit used in household wiring? 3. Why are certain metals, such as copper, silver, and gold, good conductors of electricity?

2 2 U LY from the series lectricity and Magnetism P G M Q U Z Directions: t the end of the program, there is a short quiz. You can record your answers on this sheet. 1. urrent electricity is. a. a conductor b. an insulator c. the flow of electrons d. a closed circuit 2. complete circuit is made of three things: a. n insulator, a source of electrons, and a path. b. conductor, a source of electrons, and a path. c. switch, a source of electrons, and a path. d. omething to use the electricity, a source of electrons, and a path. 3. omething that allows electrons to flow easily through it is called. a. an insulator b. a conductor c. a switch d. a current 4. omething that slows the flow of electrons is called. a. an insulator b. a conductor c. a switch d. a current 5. here are two types of circuits:. a. insulators and conductors b. closed and open c. series and parallel d. switch and current

3 3 U LY from the series lectricity and Magnetism DU Materials that allow electricity to flow easily through them are called conductors. hings that resist, or stop, the flow of electricity are called insulators. Purpose: Materials: Procedures: o identify objects as either conductors or insulators. objects to be tested 1-1/2 volt dry cell 1-1/2 volt light bulb and socket wire tape 1. Using the diagram as a guide, set up a tester. 2. nce the tester is made, use it to test the objects you have collected. Write your findings in the chart below bject ested onductor nsulator U L?

4 4 U LY from the series lectricity and Magnetism D B U L B his is an incandescent light bulb. hey are the most common sources of light and are found in homes, cars, and flashlights. hey have a special filament, often made of tungsten, that does not allow electricity to flow easily through it. he electricity heats the filament to a very high temperature, which makes the filament glow. Look at an unlit bulb. Directions: Using the following materials, how would you wire a flashlight bulb in order to make it light? Write your procedure for setting up the circuit and include illustrations. Purpose: Materials: o light a flashlight bulb with a 1-1/2 volt dry cell. 1-1/2 volt flashlight bulb 1-1/2 volt dry cell insulated wire - about 30 cm (12 inches) wire cutters or scissors Procedures:

5 5 U LY from the series lectricity and Magnetism H - W Y three-way light bulb is designed to give three different levels of brightness. hese bulbs are different from regular bulbs. hey have two filaments instead of one. n a three-way bulb that can show 50 watts, 100 watts, and 150 watts, the filaments are arranged so that one is 50 watts and the other is 100 watts. he three-way bulb must have a special socket that has different settings. he bottom of the bulb is different from a regular light bulb. ompare a three-way bulb with a regular bulb. What is different about them? hree-way bulb How would a three-way bulb give you three different light settings? B U L B egular Bulb

6 6 U LY from the series lectricity and Magnetism G L V M galvanometer is a device used to measure small electric currents. ften the currents are smaller than one volt, so a sensitive instrument must be used to show that electricity was produced. Galvanometers can be purchased, but the one described below can be easily constructed. Purpose: Materials: Procedures: o construct a galvanometer. compass knife insulated wire 1. Wrap the wire carefully around the compass about 25 times. 2. Use the knife to cut away about one inch of insulation on both ends of the wire. 3. he home-made galvanometer can now be hooked up to things to test for electric current. hings to try: 1. Get a second coil of wire and a bar magnet. ut away the insulation from the ends of the wire. Hook these bare ends to the bare ends of the galvanometer wire. Move the magnet in and out of the coil of wire. What happens and why? 2. onnect a 1-1/2 volt dry cell to the galvanometer. What happens and why?

7 7 U LY from the series lectricity and Magnetism M P L U Use the materials listed below to find different ways to get the flashlight bulb or bulbs to light. Materials: two flashlight bulbs two dry cell batteries a length of wire with the ends stripped of insulation Questions: 1. How can you set up things to light one bulb with one dry cell? (Draw a picture of each set-up.) 2. How many ways can you set up things to light both flashlights? Here is a picture of a flashlight bulb. What purpose does the ceramic material perform? What are the two important areas of the bulb that allow current to flow?

8 8 U LY from the series lectricity and Magnetism M P L Directions: Look at the picture of the bulb, dry cell, and wire, and predict whether the light would light up or not. hen test your predictions by making the illustrated circuits. Prediction esult U 2

9 9 U LY from the series lectricity and Magnetism U n electric circuit must have three things to be complete. here must be a supply of electrons, something to use the electricity, and a path on which the electrons travel. here are two kinds of circuits parallel and series. Purpose: Materials: o compare a parallel circuit with a series circuit. four 1-1/2 volt light bulbs and sockets three 1-1/2 volt dry cells insulated wire Procedures:1. efer to the diagrams and build parallel and series circuits. bservations: 1. What happens when you loosen one of the light bulbs in the parallel set-up? 2. What happens when you loosen one of the bulbs in the series set-up? onclusions: xplain why there are different results in your observations.

10 10 U LY from the series lectricity and Magnetism G ircuits can have different switches, or gates, to allow the flow of electricity. When a gate is open, the circuit isn't complete and the bulb is off. When the gate is closed, the circuit is complete and the bulb lights. o begin, make a supply of homemade aluminum foil conductors. You need aluminum foil, some masking tape, scissors, and paper clips. ear off a sheet of foil and place it so the dull side is facing up. arefully place strips of masking tape along the foil's dull side. hen cut the foil into ½-inch strips. You can make these strips any length. f you need longer strips, you can attach two strips together with a paper clip. hese foil strips can be used like copper wire for building various circuits. Use the aluminum foil-conducting strips to build the circuits and gates illustrated in the three drawings on the right.

11 11 P - U LY from the series lectricity and Magnetism Directions: nswer the following questions in the space provided. 1. What three things are needed for a complete circuit? 2. What is a conductor? 3. What is an insulator? 4. What is a series circuit? 5. What is a parallel circuit? 6. How does a circuit breaker protect a home? 7. Why are parallel circuits used in homes instead of series circuits? 8. What is a short circuit? 9. What is current electricity? 10. Draw a parallel circuit to connect these two bulbs with the dry cell. battery

12 . Directions: Pick the definition in column B that best matches the word in column. Write the letter of the definition on the blank line. olumn 1. electricity 2. conductor 3. insulator 4. attract 5. repel 6. electron 7. proton 8. neutron 9. hales LY D MGM Unit est. Directions: nswer the following questions in the space provided. 1. ame three good conductors of electricity. olumn B a. When two objects come toward each other. b. he Greek philosopher who named electricity. c. positively charged particle found in the nucleus of an atom. d. he flow of electrons. e. n atomic particle found in the center of an atom. t has no charge. f. Material that will not allow the flow of electricity. g. particle found orbiting around the nucleus of an atom. t has a negative charge. h. Material that allows electricity to go easily through it. i. When two objects move apart. 2. ame three good insulators. 3. Describe some uses for insulators. 4. How does a generator work? 5. Describe how a simple electromagnet could be made. 6. How is an electromagnet different from a regular bar magnet? 7. What three things are needed for a complete circuit? 8. here are two kinds of circuits: series and parallel. Finish the drawings below by adding wires. series battery battery parallel

13 LY D MGM Unit est (Page 2) 9. What are the differences between a series circuit and a parallel circuit? 10. How do fuses or circuit breakers help protect homes? 11. Mechanical energy of the spinning turbine and generator produce electrical energy at a power station. Give some examples of electrical energy being changed to other forms of energy around your home. 12. Fossil fuels (oil, coal, and natural gas) are the main sources of fuels used to power the electric plants of today. What are some other sources of energy that can be used to make electricity? 13. f these two magnets were to be brought near each other, how would the lines of force look? 14. f one of the magnets was flipped over, how would the lines of force be changed? 15. mperage is equal to wattage divided by voltage. alculate the number of amps for each of these electrical appliances. a. electric toothbrush 480 watts 120 volts amps b. electric blender 960 watts 120 volts amps c. microwave 720 watts 120 volts amps