07-10-02 Tigers Lab Exercise

Bruce Dillon, Bill Davis, Jennie Lynch

Hi-tech Motor

Objective: To build and demonstrate a working motor.

Equipment:

  • 1- D battery
  • Large rubber band
  • 2 - large paper clips
  • Masking tape
  • Ceramic magnet
  • Enamel coated wire (26 - gauge)
  • Steel wool

Procedure:

  1. Tape battery to table
  2. Shape paper clip (see figure 1.)
  3. Use the rubber band to attach the paper clips to the ends of the battery.
  4. Form coil of wire with protruding ends. (see figure 2.)
  5. Use steel wool to completely remove the enamel from one of the protruding ends.
  6. Next remove the enamel from only one side of the other protruding end.
  7. Place the magnet on the battery
  8. Hang the coil on the paper clips.
  9. Give the coil a slight push.

The bend at each end of the coil should probably be 90 degrees. The purpose is to keep the coil from walking, or dropping out.

Discussion:

Recognize that a current perpendicular to a magnetic field will have a resulting EMF perpendicular to both the current and the magnetic field following the right hand rule. Recognize the polarity of the battery and the orientation of the magnet in relation to the direction of rotation of the coil.

We tried 22, 26, and 30 - gauge wire and found that the 26 gauge worked best.

Questions:

  1. Does the number of turns of wire affect the function of the motor?
  2. Does the type of wire affect the motor?
  3. Why does the wire appear to oxidize?
  4. Does the strength of the magnet affect the outcome?
  5. Draw the field exhibited by the magnet.
  6. How does the position of the magnet affect the motor?
  7. Draw the magnetic field exhibited in the coil at a designated point (the point when the battery is supplying the power to the coil)
  8. State one idea on how to improve this system.
  9. State one error this system exhibits.
  10. Show what happens when the coil crosses the field of the magnet.