Post on 22-Jun-2018
THE STUDY OF FLASHLIGHTS AND THE AMOUNT OF LIGHT THAT DIFFERENT SOURCES OF
LIGHT PRODUCE
Katrine Andersen
Cary Academy
ABSTRACT
The purpose of this study was to determine if the distance that the flashlight is held effects and
determines how much light that the light probe will collect. Visible light, which is commonly referred to
as light, is part of the electromagnet spectrum, which ranges from radio waves to gamma waves. A
flashlight was placed several different distances away from the light probe it was then turned on. It
was determined that when the flashlight was placed 1 cm away from the light probe the light probe
collected more light than when farther away. It was concluded that the reason that less light is
collected when placed farther is due to the spreading of the light.
INTRODUCTION
Katie Barbery at Cary Academy School tested different batteries and the voltage loss. In addition,
Katie tested batteries to determine which battery had the greatest voltage loss and which battery had
the least voltage loss. Katie used different brands of batteries and different types of batteries like
AAA, AA batteries and C batteries. The first experiment that Katie Barbery conducted was testing the
voltage of different brands of AA batteries. Katie did this by using a Laser FX. The rest of Katie’s
experiments were similar to Katie’s first experiment. The second experiment was conducted using a
coin sorter instead of a Laser FX and replacing AA batteries with C. In the third experiment, it was
repeated, but this time was conducted using a walkie-talkie and nine voltage batteries (3 for each
test). Experiment 4 was similar to the first one but was instead conducted with a flashlight and D
batteries. For the fifth experiment the same process as the other experiments were done but using a
portable radio and AAA batteries. From the results of the experiments, Katie Barbery learned that
Raovac had the greatest voltage loss compared to all the other batteries that Katie used in her
experiments. Katie also concluded that Energizer batteries had the least voltage loss compared to the
other batteries.
What exactly is light? Many people over the years have wondered what exactly light is. Visible light,
most commonly known as light is part of the electromagnet spectrum, which ranges from radio waves
to gamma waves. Visible light is not different from the other parts of the electromagnet spectrum
however, the one exception to this is that human eyes can detect and see the visible rays as well as
gamma rays. Electromagnetic radiation can also be described in terms of a stream of photons.
Photons are massless particles each travelling with wavelike properties at the speed of light. A
photon is the smallest quantity (quantum) of energy that can be transported and it was the realization
that light travelled in discrete quanta that was the origins of Quantum Theory. Light traveling along its
straight path is known as a light ray. However, a collection or bundle of light rays make up a light
beam. A candle flame or an electric bulbs filament produces light because these items produce heat
and energy. However, there are cold sources of light such as a fluorescent tube. Light is also a form
of energy.
Figure 1. This diagram shows what happens when the sun’s rays hit a surface and then reflects off.
Humans use batteries for many appliances and everyday use. However, no one takes the time to
think why batteries supply energy and what makes a battery a battery. The anode (-), cathode (+),
and the electrolyte are the 3 parts that make up a battery. The anode is also commonly referred to as
the negative side and the cathode is commonly known as the positive side. To create energy or
electricity batteries are installed in a circuit. A circuit can also be known as the flow of electrons
through a conductive path like a wire. The chemical reaction in the battery causes a buildup of
electrons at the anode. This results in an electrical difference between the anode and the cathode. It
can also be thought of an unstable build-up of the electrons. The electrons want to rearrange
themselves to get rid of this difference. However, they do this in a certain way. Electrons repel each
other and try to go to a place with fewer electrons. In a battery, the only place to go is to the cathode.
However, the electrolyte keeps the electrons from going straight from the anode to the cathode within
the battery. When the circuit is closed, the electrons will be able to get to the cathode. The electrons
go through the wire, lighting the light bulb along the way. This is one way of describing how electrical
potential causes electrons to flow through the circuit. A battery has to be hooked up to a circuit so
that he anode and the cathode are connected and then the anode to the cathode.
+-
+ -
Batteries
Figure 2. This shows the way that the batteries are hooked up to the circuit, first the cathode (+) to the anode (-) and the anode
(-) to the cathode (+) then the cathode (+) to the anode (-).
What exactly is electricity and what forms of electricity are there? Electricity forms at the basis of a
nerve signal. Human eyes receive light rays and turn them into tiny electrical signals that pass along
nerves into the brain and the rest of the body. Our whole awareness and ability to think and move
depends on little electrical signals whizzing around the nerve pathways inside the brain. The
phenomenon associated with stationary or moving electric charges is called electricity. Electric
charge is a fundamental property of matter and is borne by elementary particles. In electricity, the
particle involved is the electron, which carries a charge designated by convention as negative. Thus,
the various manifestations of electricity are the result of the accumulation or motion of electrons. An
example of electricity is lighting. Lightning is actually a discharge of static electricity; static electricity
is where friction transfers charged particles from one body to the other. Magnetism and electricity are
related in many different ways. Electricity and Magnetism are two aspects of electro-magnetism which
is the science of charge and of the focus and fields associated with charge. Electricity and magnetism
were thought for a long time to be separate forces, not until the 19th century was they finally treated
as interrelated phenomena. Electric and magnetic forces can be detected in regions called electric
and magnetic fields. These fields are fundamental nature and can exist in space far from the charge
or current that generated them. The electric force in particular is responsible for most of the physical
and chemical properties of atoms and molecules. Electric forces are produced by electric charges
either at rest or in motion. Magnetic forces on the other hand are produced only by moving charges
and act solely on charges in motion. Electric charges are of the two general types, positive and
negative. Electric charges are called electricity, so all electric charges are electricity and vice versa.
MATERIALS AND METHODS
In these experiments a Mini Maglite flashlight, Husky flashlight, LED Technology flashlight, timer, light
probe, ruler, table, computer, green expo marker, red expo marker, black expo marker, blue expo
marker, silver sharpie, black sharpie, and a red sharpie were used.
Different brands of flashlights were tested to see, which one could produce the most amount of light.
First, the Husky flashlight was placed 5 cm away from the light probe and then was turned on and the
light probe collected the amount of light that the flashlight produced. The information was recorded
into the computer and repeated 2 more times. When done 3 times an average was determined. Then,
the LED Technology flashlight was placed 5 cm away from the light probe, the flashlight was then
turned on. The light probe collected the amount of light that the flashlight produced. The data was
recorded into a computer and the process was repeated 2 more times. Averages of the three were
measured and were calculated. Lastly, the Mini Maglite flashlight was placed 5 cm away from the light
probe and turned on. The data was recorded into a computer and the process was repeated 2 more
times, an average of the 3 was calculated.
A flashlight was placed different distances away from the light probe to see if it affected the amount of
light that the light probe picked up. The flashlight was placed 1 cm away from the light probe and
then turned on. The light probe collected the amount of light that it produced. The information was
recorded and repeated 2 more times. When done 3 times an average was determined. The flashlight
was placed 8 cm away from the light probe, it was then turned on, the light probe collected the
amount of light that it produced. The data was recorded and the process was again repeated 2 times
then taken an average. Then the flashlight was placed 15 cm away from the light probe and turned on
the data was recorded. The process was again repeated 2 times and an average was determined.
Lastly, the flashlight was placed 25 cm away from the light probe, the data was recorded and the
process was repeated 2 times. When done 3 times an average was determined.
Different brands of batteries were tested to see if it affected the amount of light that the flashlight
produced. Energizer batteries were placed in a flashlight. The flashlight was then placed 5 cm away
from the light probe. The light probe collected the amount of light produced. This was repeated 2
more times with the Energizer batteries, after 3 times an average was determined. Then, Everyday
Super Heavy Duty batteries were placed in the flashlight. The flashlight was then placed 5 cm away
from the light probe and turned on. The light probe collected the amount of light that the flashlights
produced and this was done 2 more times, an average was determined. After, Everyday Gold
batteries were placed in the flashlight, the flashlight was then positioned 5 cm away from light probe,
the light probe collected the amount of light that was produced. This was repeated 2 more times and
then an average was determined. Lastly, Kodak batteries were placed in the flashlight. The flashlight
was positioned 5 cm away from the light and the light probe collected the amount of light that it
produced. This was done 2 more times and an average was determined.
A flashlight was left on for different amounts of time to see if it affected how much light it produced.
The flashlight was placed 5 cm away from the light probe and then turned on for 1 sec. Then it was
turned on and kept on for 60 sec the light probe collected how much light was produced this was
repeated 2 more times and an average was determined. After that, it was then turned on for 120 sec
the light probe collected the amount of light that it produced this process was repeated 2 more times
than an average was determined. Then the flashlight was left on for 240 sec and the light probe
collected the amount of light that it produced this process was done 2 more times, then an average
was determined. Lastly, the flashlight was left on for 500 seconds the light probe collected the amount
of light that was produced and the data was recorded, this was repeated 2 more times, and an
average was determined.
A flashlight was placed different distances away from a mirror to see if it affected the amount of light
that the mirror reflected. The flashlight was first placed 1 cm away from the mirror the light probe
collected the amount of light that reflected. The data was recorded and the process was repeated 2
more times, an average was then determined. Then the flashlight was placed 6 cm away from the
mirror, the light probe collected the amount of light that was reflected off. The data was recorded and
the process was repeated 2 more times an average was then determined. After that, the flashlight
was placed 18 cm away from the flashlight, the light probe collected the amount of light that the mirror
reflected. The data was recorded and the process was repeated 2 more times, an average was
determined. The flashlight was then placed 30 cm away from the mirror and the light probe collected
the amount of light that was reflected. The data was recorded and the process was repeated 2 more
times, an average was then determined. After, the flashlight was placed 40 cm away from the mirror
the light probe collected the amount of light that was reflected. The data was recorded and the
process was repeated 2 more times. An average was determined.
Different brands of soap were placed over the lens of a flashlight to see if it affected the amount of
light that the flashlight produced. The experiment was first conducted with using no soap, the
flashlight was placed 5 cm away from the light probe and the amount of light the flashlight produced
was recorded, this was repeated 2 more times and then an average was determined. Soft soap was
placed over the lens of the flashlight and then the flashlight was placed 5 cm away from the light
probe. The amount of light produced was recorded and the process was repeated 2 more times. An
average was then determined. Then Dial soap was placed over the lens of the flashlight. The amount
of light was recorded and the process was repeated 2 more times. An average was then determined.
After that Up and Up soap was placed over the lens of the flashlight the light probe collected the
amount of light produced and the data was recorded. This process was repeated 2 more times, an
average was then determined.
Different colors of plastic were placed over the flashlight to see if it affected how much light was able
to come through. The first color was blue. The flashlight was placed 1 cm away from it the light probe
on the other side of the color collected the amount of light that came through. This process was
repeated 2 more times an average was then determined. The second color to be used was red. The
light probe on the other side of the color collected the amount of light that came through. This process
was repeated 2 more times and an average was determined. The third color to be tested was silver.
The light probe collected the amount of light that came through and the data was recorded. This
process was then repeated 2more times. Then an average was determined. The last color that was
tested was black. The flashlight was placed 1 cm away from the color and then was turned on. The
light probe collected the amount if light that came through. The data was recorded and an average
was determined.
Different colors of mirrors were tested to see if it affects how much light that reflected. The first color
that was tested was green. The flashlight was placed 5 cm away from the mirror and the light probe
on the other side. The flashlight was turned on and the light probe collected the data. This process
was repeated 2 more times and then an average was determined. The second color that was tested
was blue. The flashlight was placed 5 cm away from the mirror and the light probe on the other side.
The flashlight was turned on and the light probe collected the data. This process was repeated 2
more times and then an average was determined. The third color that was tested was red . The
flashlight was placed 5 cm away from the mirror and the light probe on the other side. The flashlight
was turned on and the light probe collected the data. This process was repeated 2 more times and
then an average was determined. The fourth color that was tested was black. The flashlight was
placed 5 cm away from the mirror and the light probe on the other side. The flashlight was turned on
and the light probe collected the data. This process was repeated 2 more times and then an average
was determined. The last color that was tested was clear. The flashlight was placed 5 cm away from
the mirror and the light probe on the other side. The flashlight was turned on and the light probe
collected the data. This process was repeated 2 more times and then an average was determined.
Different sizes of width of candles were tested to see if it affected the amount of light that the candle
was producing. A 1.75 cm candle was tested first. It was placed on a table and the light probe was
placed 5 cm away from it. The candle was then lit, using matches and the light probe collected the
amount of light that the flashlight produced. This process was repeated 2 more times and then an
average was determined. A 3.5 cm candle was tested second. It was placed on a table and the light
probe was placed 5 cm away from it. The candle was then lit, using matches and the light probe
collected the amount of light that the flashlight produced. This process was repeated 2 more times
and then an average was determined. A 7 cm candle was tested third. It was placed on a table and
the light probe was placed 5 cm away from it. The candle was then lit, using matches and the light
probe collected the amount of light that the flashlight produced. This process was repeated 2 more
times and then an average was determined.
A candle was placed at different distances from a light probe to see if it affected how much light the
light probe collected. The candle was placed 1 cm away from the light probe and then lit using a
match. This process was repeated 2 more times and then an average was determined. Then the
candle was placed 8 cm away from the light probe and then lit using a match. This process was
repeated 2 more times and then an average was determined. After that, the candle was placed 15
cm away from the light probe and then lit using a match. This process was repeated 2 more times
and then an average was determined. Last, the candle was placed 25 cm away from the light probe
and then lit using a match. This process was repeated 2 more times and then an average was
determined.
RESULTS AND DISCUSSION
Figure 3. As shown, the different types of flashlights affect how much light is produced.
It was determined in the first experiment that the type of flashlight used does affect how much light
that is produced. This is because of the wattage of the light bulb inside the flashlight. However, the
wattage does not make a big difference in how long that the light of the flashlight lasts the wattage
should not make a difference in how long a bulb last. However, it will make a bigger difference in how
much light that the flashlight produces. A higher wattage bulb will draw more current and then in
result the flashlight will produce a brighter light. The lower the wattage of the bulb is, the flashlight will
draw less current and this result in dimmer light than the higher wattage bulb. This is why the LED
Technology flashlight produced a brighter light than all the other flashlights because it had a higher
wattage bulb. It can also be concluded that the Husky flashlight had the lowest wattage bulb. This
was concluded because the Husky flashlight produced the dimmest amount compared to all the other
flashlights. The higher the wattage of the bulb the brighter the light it and the lower the wattage of the
bulb is the dimmer the light is.
0
200
400
600
800
1000
1200
Husky LED Technology Mini Maglite
Am
ou
nt
of
Ligh
t P
rod
uce
d (
lux)
Flashlight Used
Figure 4. As seen, the distance away from the flashlight affects how much light is picked up.
In the second experiment, it was found that the distance away from the flashlight affects the amount
of light that is collected. This is mainly because of the spreading of the light. Whenever the flashlight
is up close to the light probe it collects more light because it does not spread over a wide range.
However, whenever the flashlight is moved farther away from the light probe the amount of light that
the light probe picks up is less. The spreading of the light caused all this. As it was shown in figure 4,
when the flashlight was only 1 cm away from the light probe it collected up to 2650 lux. But, when the
flashlight was moved to 8 cm away it only picked up 1072 lux and then when it was 25 cm away from
the light probe it collected a mere 618 lux. The spreading of the light is what caused all of this. The
closer that the light is to the light probe the more light it collects and picks up and the farther away
from the light probe is the less light is collected this is due to the spreading of the light. Therefore,
from this it was concluded that the closer the flashlight is the more light it produces.
0
500
1000
1500
2000
2500
3000
0 5 10 15 20 25 30
Am
ou
nt
of
Ligh
t P
rod
ucr
ed
(lu
x)
Distance Away from Flashlight (cm)
Figure 5. As is shown, the brand of battery has little effect on how much light the flashlight produced.
In the third experiment, it was found that the brand of the battery has little effect on how much light
the flashlight produces. The flashlight uses the same amount of energy from the battery regardless of
the type of battery. It is only up until the last few minutes or hours that a change in the amount of light
produced would be noticed. This is because the flashlight is using the remaining energy that the
battery has to produce light and the flashlight may have to use less so than the amount of the light
produced would be smaller. However, brand new batteries were used to conduct the experiment so it
had very little effect on the amount of light that it produces. In all, there is no major difference
between the different brands of batteries that were used. All of the batteries stayed around 720 lux
with only a minor spike from Energizer batteries. From this, it was concluded the brand of battery
does not have an effect on the amount of light produced.
Figure 6. As is shown, the amount of time that the flashlight is left on for has little effect on how much light it produced.
0
100
200
300
400
500
600
700
800
900
1000
Everyday SuperHeavy Dutey
Energizer Everyday Gold Kodak
Am
ou
nt
of
Ligh
t P
rod
uce
d (
lux)
Brand of Battery
0
100
200
300
400
500
600
0 100 200 300 400 500 600
Am
ou
nt
of
Ligh
t P
rod
uce
d (
lux)
Amount of Time Left on (sec)
In the fourth experiment, it was found that the amount of time that the flashlight is left on for has little
effect on how much light it produces. Keeping in mind the result from the previous experiment, the
brand of battery does not have an effect on how much light that the flashlight produces. This relates
to the previous experiment because the flashlight will keep using the same amount of energy from the
battery until there is little to no energy left, then the flashlight produces less and less light until the
battery is dead. In this experiment, however, the amount of time was to short to make a difference
because the batteries could still supply the same amount of energy. This was supported because on
10 sec, the flashlight produced around 519.5 lux but then when it was at 500 sec it was still producing
around 430 lux. This a small change of the light that was produced.
Figure 7. As seen, the distance that the flashlight was held from the mirror has effect on how much of the light was reflected.
In the fifth experiment, it was found that the distance away from the mirror/surface had effect on how
much light was reflected. This was because of the spreading of the light as was described in the
second experiment. So the closer the flashlight was held to the surface/mirror the more light the
surface/mirror reflected because more light had hit it in the beginning. In addition, the farther away the
flashlight was held the less light was reflected because of the amount of light that actually hit the
surface/mirror due to the spreading of light. This is because the farther away the flashlight is held the
less amount of light is collected. As a result, when the flashlight when was 1 cm away from the
surface/mirror it reflected around 210 lux and when it was 40 cm away it only reflected around 20 lux.
0
50
100
150
200
250
0 10 20 30 40 50
Am
ou
nt
of
Ligh
t R
efl
ect
ed
(lu
x)
Distance the Flashlight is From the Mirror/Surface (cm)
Figure 8. As seen, the brand of soap does not have a huge effect on how much light it let through.
In the sixth experiment, it was determined that the brand of soap that is used over the lens of the
flashlight does not cause a huge effect, but that the soap does cause some of the light to be blocked
off. The reason for this is that the soap absorbs the light. Therefore, when the soap absorbs the light
there will be less light coming through. In addition, that the brand of soap does not matter because it
is made up of the similar ingredients. But when there is no soap there is more light produced and
collected because none of it is absorbed as it would have been with soap. This was supported by the
graph because the 3 different brands of soap all collected around 138 lux of light, but when there is
no soap on the flashlight lens there is more light produced. Just because less light is collected does
not mean that the flashlight produces less light because of the soap it simply means that the soap
was what was causing the decrease in light collected because the soap is absorbing the light that
comes.
0
50
100
150
200
250
300
350
Soft Soap Dial Up&Up No Soap
Am
ou
nt
of
Ligh
t U
Sed
(lu
x)
Brand of Soap Used
0
50
100
150
200
250
Clear Blue Red Silver Black
Am
ou
nt
of
Ligh
t Le
t Th
rou
gh (
lux)
Color
Figure 9. As seen, the different colors have effect on how much light that was let through.
In the seventh experiment, it was found that the color that is put up in front of the flashlight does affect
how much light is able to come through. The reason for this was that different colors absorb light
differently. As the graph shows, the color of the plastic wrap does have some effect on how much
light is able to come through. The reason for this is that colors absorb light differently. The graph
shows that the darker the color gets the more light is absorbed and the lighter the color is the less
light was absorbed. Clear plastic wrap let 200 lux of light to go through where black let only about 75
lux through.
Figure 10. As seen, the color of the mirror effects how much of the light was reflected.
In the eighth experiment, it was determined that the color of the mirror had an effect on how much
light was reflected off the mirror. It was also concluded that the black mirror reflected less light than
the clear mirror. This was because the darker the color of the mirror the more light is absorbed
resulting in less light reflecting and vice versa. An example of this would be the difference between
the reflection of the black and the green mirror. When the mirror color was green it reflected about
280 lux, however the black color of the mirror only reflected about 115 lux. This is a huge difference
between the two and is a clear example of why the color of the mirror effects how much light is
reflected. Overall, it was concluded that color clear reflects the most light and color black reflects less
light.
0
50
100
150
200
250
300
350
400
Green Blue Red Black Clear
Am
ou
nt
of
Ligh
t R
efl
ect
ed
(lu
x)
Color of Mirror
Figure 11. As shown, the width of the candle effects how much light was produced.
In the ninth experiment, it was determined that the size of the candle has some effect on the amount
of light that the candle produces. The reason for this is the candlewick on the candle. The larger that
the candle was the larger the wick was. The wick is what mainly controls the flame and the amount of
light that candle gives off. Keeping this in mind, the larger the candle got in the experiment the larger
the wick of the candle is. This was supported by the graph because when the candle was 1.5 cm wide
the candle only produced about 36 lux of light and when the candle was 7 cm wide the light that it
was produced was greater being about 46 lux of light produced. The graph shows that the thicker the
candle was the more light was produced.
Figure 12. As seen, the distance away from the candle affects how much light is collected.
0
5
10
15
20
25
30
35
40
45
50
0 1 2 3 4 5 6 7 8
Am
ou
nt
of
Ligh
t P
rod
uce
d (
lux)
Size of Candles Width (cm)
0
50
100
150
200
250
300
350
0 5 10 15 20 25 30
Am
ou
nt
of
Ligh
t P
rod
uce
d (
lux)
Distance Away (cm)
In the tenth, experiment it was determined that the distance away from the candle effects how much
light was collected and the farther away the less light was collected. The same thing applies as to the
other experiments that the spreading of the light has a lot to do about how much light reaches
somewhere at different distances away. The farther away that the light probe was from the candle the
less light was able to pick up. This was mainly due to the spreading of the light, the farther that the
candle goes from the light probe; the less amount of light was collected because the spreading of the
light was bigger. However, if the candle was closer to the light probe, then the amount of light that
was recorded will be larger due to the spreading of light. This was because the light does not spread
out as for because it was more focused one just one object. That was why when the flashlight was at
1 cm the light probe collected about 325 lux but when the candle was 25 cm away from the light
probe the light probe only collected about 17 lux of light. This was all due to the spreading of the light
and the distance which the candle was placed.
CONCLUSION
It was determined that the brand of flashlight affects how much light was produced. If the choice was
between an LED technology flashlight and a Husky the better choice would be the LED Technology
flashlight because it produced the most light compared to all of the other flashlights. The data
recorded supported the hypothesis that was made because the LED Technology flashlight produced
more light than the other flashlights. It could be interesting to see whether the temperature
surrounding the flashlight has effect on how much light the flashlight produces.
CITATIONS
Barbery, Katie. “The Study of Voltage Loss of Different Brands of Batteries”. Cary Academy. 2010.
Brain, Marshall. "How Batteries Work.". HowStuffWorks. HowStuffWorks, Inc. 2013. Web. 2/2/2013
“Energy Activities for Teachers and Students.” Energy Information Administration. 11 February 2007. Web.
2/2/2013
Gregersen, Erik. Electricity and Magnetism. New York: Britannica Educational Publishing, 2011. Print.
Lewis, Peter. Light and Sound. Tuscan: Brown Bear Books Limited, 2010. Print.
Parker, Steve. Electricity. New York: DK Publishing, 1992. Print.