demonstrations:simple_electric_motor

Simple Electric Motor

Materials: ★★☆ Available in most school laboratories or specialist stores
Difficulty: ★★☆ Can be done by science teachers
Safety: ★☆☆ Minimal safety procedures required

Categories: Electricity, Magnetism, Motion

Alternative titles: Homemade Electromagnet Motor

Summary

A simple electric motor is built using a coil of wire, a battery, paperclips, and strong magnets. The motor works by converting electrical energy into mechanical motion through the interaction of a magnetic field from a permanent magnet and a temporary magnetic field created by current flowing in the coil.

Procedure

  1. Build motor according to instructions in the links.
  2. Adjust coil balance, magnet position, and stripped wire surfaces if needed to get the motor running smoothly.

Build a Simple Electric Motor | Science Project - Science Buddies:


3 Simple DIY Motor Experiments - Science Buddies:


📄 The simplest motor - Institute of Physics: https://spark.iop.org/simplest-motor

Variations

  • Compare circular and square coils, keeping the same wire length.
  • Test with one, two, or three stacked magnets to see how field strength affects speed.
  • Flip the coil or motor upside down and observe direction of spin.
  • Add a second battery in series to increase current and field strength.
  • Modify the setup to include a switch for turning the motor on and off.

Safety Precautions

  • Do not connect the motor to a wall outlet—use only batteries.
  • Handle neodymium magnets carefully—they are strong and can pinch skin or snap together.
  • Coils can heat up if left connected too long—allow them to cool before touching.

Questions to Consider

  • What is the difference between a permanent magnet and an electromagnet? (Permanent magnets always have a magnetic field; electromagnets only produce one when current flows.)
  • Why does stripping only half the insulation from one axle make the motor spin continuously? (It allows current to flow only during part of the rotation, so the coil always gets a push in the same direction.)
  • How does the number of magnets affect motor speed? (More magnets increase field strength, making the motor spin faster up to a point.)
  • How does Fleming’s left-hand rule explain the direction of motion? (It shows the relationship between current, magnetic field, and the resulting force on the wire.)
  • What would happen if you used a second battery in series? (It would increase current and make the electromagnet stronger, likely spinning the coil faster.)