Which Brand of Light Bulb Gives Most Light?

Researched by Cody H.
2000-01


PURPOSE 

The purpose of this experiment was to determine which brands of 60 watt light bulbs actually gave out the most light.

I became interested in this idea because I was fascinated with electricity.  So I decided to do something including light bulbs.

The information gained from this experiment can help the world know about light bulbs and which ones to trust.  It can also help consumers find the kind of light bulbs they should buy. 




HYPOTHESIS

My hypothesis was that most 60 watt light bulbs would give out the same amount of light.

I based my hypothesis on the World Book Encyclopedia because it states the most information you can find on light.

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EXPERIMENT DESIGN

The constants in this study were:

 -The same socket
 -The same amount of electricity
 -The same wooden box
 -The same distance away with the computer powered probe
 -The same room 
 -The room temperature is the same 
 -The same day
 -The same person doing the experiment (Cody Helms) 
 -The same type of experiment
 -Each bulb will be 60 watts
 -The same temperature of light bulbs
 -The same computer
The manipulated variable was the different brands of light bulbs.  The brands were Sylvania, Western Family, GE Lighting, Value Bright, and Disadvantage Workers.

The responding variable was the intensity of the light at the distance of 20 centimeters.

To measure the responding variable I used a computer probe to see how much light was coming out of each light bulb at a distance of 20 centimeters.

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MATERIALS
 
QUANTITY  ITEM DESCRIPTION
 5 Different Brands of 60 watt Light Bulbs
1 Wooden Box with a Light Socket
1 Room with light
1 Assistant
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PROCEDURES
  1. Do all of the tests in the same room with the same box.
  2. Get four each of five brands of light bulbs.
  3. Get a wooden box with a light socket in it for the experiment so you can measure how much light they're giving out with a computer powered probe.
  4. Put the first light bulb in the socket and turn the light and computer on and conduct four trials for five seconds each. 
  5. Repeat steps 6 and 7 with the other 4 brands of light bulbs.

  6. Be sure to record all the data from the experiment.
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RESULTS

The original purpose of this experiment was to determine which brands of 60 watt light bulbs actually gave out the most light.

The results of the experiment were that the brands all gave off a different amount of light.  Sylvania gave out the most, Western Family gave out the second most, GE got third, Value Bright got fourth, and Disadvantage Workers gave out the least.  Each bulb in each brand gave off a different amount of light.

See the Table and Graph

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CONCLUSION

My hypothesis was that most 60 watt light bulbs would give out the same amount of light.

The results indicate that this hypothesis should be rejected.

Because of the results of this experiment, I wonder if the same results would be true for 100 watt light bulbs.

If I were to conduct this project again I would like to try to measure the light in Lumens.  I would also have a totally dark room.

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Research Report

Light

 The world depends on light.  Light is given off as the result of atoms within a substance being given energy.  It is a form of energy, just like heat and sound. Light energy is constantly given off from hot objects, so we see light when things burn.
Light comes from atoms.  It is produced by atoms that have gained energy either by absorbing light from another source or by being struck by other particles.  An atom with such extra energy is said to be excited.  Ordinarily, an atom stays excited only briefly.  It de-excites by giving up its extra energy, or it can emit light.  The light then carries away the extra energy. 

History

Ideas about light go back thousands of years ago.  A Greek engineer named Hero wrote a book about mirrors and light in the first century A.D.  He believed that light was a kind of "feeler" or antenna sent out by the eyes to detect the things we see.  Around 900 years later an Arabian physicist figured out that light comes from one source, such as the sun, and that everything we see reflects light from the source to our eyes. 
The earliest experiments of electric light were made in the early 1800s by a British chemist Sir Humphrey Davy, who created a fine platinum wire incandescent in air by passing a current through it. He also created electric arcs.  In 1878 and 1879 British inventor Joseph Swan and American inventor Thomas Edison simultaneously developed the carbon filament lamp.  Improved vacuum pumps and the increased availability of electricity made these lamps a success.  The American pioneer in electrical engineering, Charles Francis Brush, produced the first commercially successful arc lamp in 1878. 

Electricity

 Electricity is the physical phenomena from the behavior of electrons and protons that is caused by attraction of particles with opposite charges and the repulsion of particles with the same charge.  Electricity is a flow of electrons. 

Natural Light

 Natural light and artificial light are basically created the same, light is given off as a result of atoms with a substance of energy.  There are different types of natural light, such as light from the sun, moon, stars, and bioluminescent organisms.  Sunlight is called white light, but it is really a bunch of different colors that form white light.  Moonlight is the reflection of the sun.  The sun is actually a star. Animals, fungi and bacteria that emit light are called bioluminescent organisms.  The production of light in bioluminescent organisms results from the conversion of chemical energy to light energy.  An example of a bioluminescent animal would be a firefly or a glowworm. 

Artificial Light

 The types of electric lighting devices most commonly used are the incandescent lamp, the fluorescent lamp, and the different kinds of arc and electric discharge lamps.
 If an electric current is passed through any conductor that is not perfect, a certain amount of energy is expanded that appears as heat in the conductor.  In as much as any heated body will give off a certain amount of light at temperatures above 525 degrees C, a conductor heated above that temperature will act as a light source.  The incandescent lamp consists of a filament of a material with a high melting point sealed inside a glass bulb from which the air was removed, or which is filled with an inert gas.  Filaments with high melting points must be used because the proportion of light energy to heat energy radiated by the filament rises as the temperature increases, and the most efficient light source is obtained at the highest filament temperature. 
 Electric discharge lamps depend on the ionization and the resulting electric discharge in vapors or gases at low pressures if an electric current is passed through them.  The fluorescent lamp is another type of electric discharge device used for general-purpose illumination.  It is a low-pressure mercury vapor lamp contained in a glass tube, which is coated on the inside with a fluorescent material know as phosphor.  A fluorescent tube taking 40 watts of energy produces as much light as a 150 watt incandescent bulb.  Because of this illuminating power, fluorescent lamps produce less heat than incandescent bulbs for comparable light production, resulting in lower energy costs. 

Measuring Light

 Light has several characteristics that can be measured.  The length of light waves is measured in hertz. Sometimes the direction of scattered light is also an important quantity to measure. 
 When light is considered as a source of illumination for human eyes, its intensity, or brightness, is measured in units that are based on a modernized version of the perceived brightness of a candle.  The rate of energy flow in this case can be stated in watts, or Joules per second.  Usually light contains many colors and radiates in many directions away from a source such as a lamp.

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Bibliographry

Cobb, Vickie Light Action 
"Electric Lighting" Encarta Encyclopedia
"Light" World Book Encyclopedia, 1999
"Light" Columbia Encyclopedia, 2000
Morgan, Sally Using Light 

ACKNOWLEDGEMENTS

I would like to thank the following people for their help with my science project:

  • Mr. Newkirk helped me by helping me get information on light and by pushing us to the end. 
  • Ms. Pasckvale was also very helpful because she made it possible to have pictures in my project.
  • David McMillen of the Selah Junior High School Science Department helped me by letting me use his computer probe. 
  • Cassandra let me use a box for measuring light. 
  • My mom helped me a lot by encouraging me to finish with pride. 


 I probably wouldn’t have a project as good as this one if it wasn’t for these people so thank you all a lot. 


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