## Magnets and Motors

posted by guy on 20 Mar 2013
last changed 30 Mar 2014

 Select ratingGive it 1/5Give it 2/5Give it 3/5Give it 4/5Give it 5/5Cancel rating No votes yet Your vote (click to rate)ages: 9 yrs to 99 yrs A sequence of lessons on magnets and motors to cover 5 to 6 classes (each 30 to 60 minutes) in logical progression.
subjects: Engineering, Physics

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Iron and MagnetslessonInstructor should read this first for general background on magnets and magnetic materials. Have students do the activities on identifying magnetic materials, find the north pole, and iron filing art.
Lorentz forcecurriculumIntroduce the Lorentz force before building motors.
 A Survey of Simple Electric Motors lesson Instructors should read this first for background on electric motors. Use the attached slides to introduce the idea of the Lorentz force when students begin work on Classroom Rail Gun (next). Classroom Rail Gun lesson Use this device as a class demo to introduce the Lorentz force, the concept behind the electric motor, before students build other more complicated motors.
 Faraday Motor lesson Let pairs of students build this device. Get them to explain how it works in terms of the Lorentz force. Discuss the nature of the electric current in salt solution. Minimalist Motors lesson Have each student build the D battery version of this device. Let them take it home to show the parents and explain how it works. Don't forget to have Neo disk magnets for everyone and plenty of 30-gauge copper wire. An Electric Screw Motor lesson Another simple motor using only a D battery, a magnet, a screw and a wire. Don't bother with the LEDs; just have students resuse the materials from their Homopolar Motors (previous). Talk about the similar device that measures electricity usage. Safety Pin Motor lesson Use this motor to introduce the idea of a rotating switch ("commutator"). Start with a demo where the coil ends are completely bare (and the motor won't work) and have students think about how to modify the design to work. Let them work in pairs.