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Science Fair
Project
Doing an
experimental Science Project?
Making a working model of an
electric motor by itself is a good educational activity and a
perfect display project; however, if you have selected this subject
as an experimental project, you will need to perform experiments in
order to find answers to a specific question about electric motor.
Following are samples of questions that may be studied as an
experimental science project.
How do the material used in the
construction of an electric generator affect the production of
electricity?
How does the number of loops of
wire in the coil affect the amount of electricity?
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Experiment: |
While winding wire around
the generator, count the number of turns you wind. After 100
turns, make a small loop on the wire, twist it, and label it
as 100. Hold the loop toward outside so you will not loose
it after winding more wire.
Continue to wind the second
100 turns. Make another loop and mark it as 200.
Continue to wind the third
100 turns. Make another loop and mark it as 300.
Continue to wind the fourth
100 turns. Make another loop and mark it as 400.
Continue to wind any
remaining wire and label the end of wire with final number
of loops. For example if you made 15 more loops, label it
415.
Sand the area of all loops
as well as the beginning and the end of the wire.
Get a volt meter or
multimeter and set it to the lowest range of AC Voltage.
Connect one probe of the
meter to the beginning of the wire coil on the generator.
Connect the generator to an electric drill (not battery
operated drill) and start the drill while holding the
generator. Ask your assistant to use the other probe of the
voltmeter to the loops 100, 200, 300 and 400 while reading
the voltage on the meter. (If you don't have an electric
drill, just spin the rotor with hand as fast as you can.
Observe the voltage. Repeat that a few times for each number
of loops and then record the average. You may not need an
assistant if you are not using an electric drill.) |
How does the diameter of coil wire
affect the electric current?
How does the speed of turning affect the production of electricity?
How does the diameter of wire coil affect the amount of electricity?
After you select your question, you
must come up with an educated guess about the results. That will be
your hypothesis.
Finally you will perform
experiments and enter your results in a data table. You may finally
use your results to make a graph.
Sample question 1:
While making the wooden generator,
I noticed that wood is fragile and can not be used to make long
lasting generator. I am wondering if metals, plastics or strong
cardboards can be used instead.
Sample Hypothesis 1:
Plastic and cardboard boxes will
function as good as wood and they may offer a better mechanical
strength and durability. Iron and steel will attract the magnet and
may redirect the magnetic field. With no magnetic field on copper
wires, we will not have any electricity. Aluminum and copper can not
be magnetized and magnetic field can pass through them. I expect a
strong working electric generator with a box constructed from copper
or aluminum.
Sample Experiment 1:
Construct five identical generators
with five different materials for the box. Use the same type and
length of wire, the same size and shape magnet, and finally the same
shape and size axle for all generators.
Spin the magnet (rotor) at a
constant speed and use a voltmeter to measure the voltage. Record
the voltages in your data table.
Note: You may use an electric drill
to spin the axis at a constant speed.
Sample Results table 1:
| Box
Material |
Produced
Voltage |
| Wood |
|
| Cardboard |
|
| Aluminum |
|
| ....... |
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Sample question 2:
While making the wooden generator,
I noticed that instructions recommend to wrap the wire at least 200
turns around the box. I am wondering why more than 200 turns? How
does the number of loops of wire in the coil affect the amount of
electricity?
Sample Hypothesis 2:
As the number of loops of wire
increase, more free electrons in the wire will be in magnetic field.
As a result by increasing the number of loops, more electron
pressure will be produced and the produced voltage will be higher.
Sample Experiment 2:
Construct four identical generators
with four different number of loops of wire on the box. Use the same
type of wire, but turn the wire coil as follows:
- For generator number 1, wrap
50 turns of wire.
- For generator number 2, wrap
100 turns of wire.
- For generator number 3, wrap
150 turns of wire.
- For generator number 4, wrap
200 turns of wire.
All other specifications on four
generators that you construct must be the same.
On each generator, spin the magnet
(rotor) at a constant speed and use a voltmeter to measure the
voltage. Record the voltages in your data table.
Note: You may use an electric drill
to spin the axis at a constant speed.
Sample Results table 2:
| Loops of
wire in the coil |
Produced
Voltage |
| 50 |
|
| 100 |
|
| 150 |
|
| 200 |
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What is happening?
When the magnet (rotor) spins
inside the coil of insulated copper wires, the free electrons inside
the wire are pushed back and fort. When these electrons are trying
to pass through very thin filament of the light bulb, they will
create such a high amount of friction and heat that will produce
light.
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