Experiment - A model electric motor
In this experiment you will examine the basic requirements for an electric motor and construct yourself a simple model motor.
The battery used must be NEW, and the copper wire must be of high quality and reasonably thick (>1mm diameter).
One form of electric motor is shown in the example below but this is only one design. Research the internet to identify a variety of designs then list the equipment required, locate the equipment and build a working electric motor. Many simple electric motors are shown on sites such as YouTube.
To construct and test a model electric motor
1 x AAA Duracell of Energizer battery
1 x round neodymium magnet (12 to 15 mm diameter)
1 x 20 to 25 mm steel screw
1 x 150 mm length of insulated copper wire with ends exposed (> 2mm diameter wire is preferred)
One end of the copper wire was prepared to create a brush like structure.
The neodymium magnet was attached to the head of the steel screw.
The screw was then carefully hung from the bottom of the battery using the magnetic attraction between the neodymium/screw and the battery.
The copper wire was clamped under a finger on the negative terminal of the battery (see diagram). The other end of the wire, with the end prepared as a brush, was then brought into gentle contact with the magnet.
The result was recorded in a Table.
The magnet was flipped over to see whether this affected the performance of the motor.
The results were recorded and a conclusion made.
If you used an alternate design rewrite the instructions to make your motor so that someone else could build a motor just like your chosen design.
- What happened when the copper wire was brought into gentle contact with the magnet?
- Why is it important to use a fresh battery? Hint as a battery ages the ability of the battery to supply a voltage remains relatively constant but the current supply slows down.
- List all the parts of your motor in a table with the headings part and function. Analyse the function of each bit of your motor and complete your table.
- Analyse a variety of motor designs and try to describe why each motor type works. Evaluate the benefits of each design.
- Simple electric motors almost always work on DC electricity. Most appliance motors though are designed to run on AC electricity. Identify the differences in design of a simple DC and AC electric motor.