Grade Level/Subject Physical Science 8th grade Unit Electricity Enduring Electricity and magnetism interact to make Understanding electromagnetism. SOL Objectives PS.11 The student will investigate and understand basic principles of electricity and magnetism. Key concepts include: b) electromagnets; and c) motors and generators.

Title Build a DC Motor Lesson Objective: Build a model of an electric motor. Analyze the workings of the parts of a motor. Inquiry Level 2 Materials Needed Battery 4.5 v, foam cup, disc magnet (4) magnet wire, permanent marker, paper clips, sandpaper, tape, tube, cardboard, alligator clips How is it Level 2? Teacher provides the research question and the methodology. Students gather data after performing a routine procedure. Students draw conclusions from guided questions. Build a DC Motor Lab- Electromagnetism Name ______Date ______Per ______

Teacher’s note: This lab can be conducted with small dc motors for data collection and evaluation separately. Stretch images as needed. Introduction: You have learned that electricity moves through wires to make electromagnetism. Electric motors can be used for many things. They cause motion in elevators and fans. Even some cars and buses are powered by electric motors. In this lab, you will build a direct current electric motor—the basis for the electric motors you use every day.

Hypothesis: How will reversing polarity affect a motor’s spin? ______

Objectives: Build a model of an electric motor. Analyze the working motor parts. Explain the effect of current on motor motion.

Procedures: 1. Make the spinning armature for the motor by winding the wire around the tube. Wind the ends of the wire around the loops on each side of the coil. Leave about 5 cm of wire free on each end. 2. Hold the coil on its edge. Sand the wire coating from the top half of each wire end. Partially unfold two paper clips to make “Y” holders for the coil, see image.

3. Place two magnets in the bottom of the cup and two on the outside of the inverted cup. The attraction holds the magnets in place. 4. Tape the paper clips to the sides of the cup. The hooks should suspend the coil. Test the coil that it rotates freely. 5. Attach the alligator clips to the battery and the bottoms of the paper clips to get a current through the coil. 6. Spin the coil clockwise and record your observations. Spin it counter-clockwise and record you observations. 7. Reverse the alligator clips on the battery. Repeat step 6. 8. Re-clip two batteries in series. Repeat step 6. 9. Reverse the polarity at the batteries. Repeat step 6. 10. Clip two batteries in parallel configuration, spin the coil. Repeat step 6. 11. Reverse the polarity of the batteries. Repeat step 6.

Gathering Data: Battery Polarity Spin direction Explain Coil motion configuration Single normal clockwise Single normal counter clockwise Single reversed clockwise Single reversed counter clockwise Two in Series normal clockwise Two in Series normal counter clockwise Two in Series reversed clockwise Two in Series reversed counter clockwise Two Parallel normal clockwise Two Parallel normal counter clockwise Two Parallel reversed clockwise Two Parallel reversed counter clockwise

Analyzing Results: 1. Did your motor always spin in the direction you started it? Explain.

2. How does changing polarity affect the coil motion?

Drawing Conclusions: 3. How does changing the polarity affect the electron motion?

4. How might electric cars promote less pollution than gas cars?

5. How could your motor be used to lift an elevator? (Think of your motor in a bigger scale and using simple machines.) Reviewing Vocabulary: 1. An ______motor converts electrical energy into mechanical energy. 2. An electrical ______uses electromagnetic induction to change mechanical energy into electrical energy.