Design Overview
This is the design overview of the report. It describes the main purpose
for the experiments to be carried out In order to investigate the link between
the factors and the resistance, a few experiments regarding to their designated
factors must be done. This will be a report with multiple experiments, being
analyzed and documented separately, and only being linked (concluded) at last.
Aim
To investigate the factors that
affect resistance
Research
Question
What link can be generated between
the factors and the resistance?
Hypothesis
Factors affecting the flow of
electron affect resistance
Experiment
1
Design
Aim
To investigate the relationship
between resistance and the length of the wire
Hypothesis
The longer the length of the wire,
the higher the resistance
|
Variables
|
Ways
|
|
|
Constant
|
The
current and voltage flowing through the circuit
|
By
using the same batteries with each of the experiments to ensure the constancy
of the voltage and current
|
|
Manipulated
|
The
length of the wire
|
Measure the wire thrice before
cutting and cut it with sharp object to ensure accuracy
|
|
Responding
|
The
resistance of the circuit
|
Calculate resistance by taking down
the voltage and current, substituting them into the formula V=IR
|
Apparatus
1. 1
ammeter
2.
2 crocodile clips (red & black)
3.
2 1.5V batteries
4.
1 0.5m SWG26 Nichrome wire
5.
1 0.75m SWG26 Nichrome wire
6. 1
1m SWG26 Nichrome wire
Procedure
1. Arrange
the apparatus accordingly to the circuit stated
2.
Complete the circuit with the 0.5m
Nichrome wire
3.
Note down the reading of the ammeter
4. Repeat
step 2 and 3 with 0.75m and 1m Nichrome wire
Safety
Procedure
1. Do
not connect the circuit by holding the wire and the Nichrome wire with hands
2. Use
low voltage batteries to avoid the danger of being electrified
Data
The
following is a table regarding to the results of the experiment:
|
Diameter
|
Type of wire
|
Length (m)
|
Voltage (V)
|
Current (A)
|
Resistance (Ohms) V=IR
|
|
SWG26
|
Nichrome
|
0.5
|
3
|
0.35
|
8.57
|
|
0.75
|
3
|
0.25
|
12.1
|
||
|
1
|
3
|
0.18
|
16.67
|
Observation
There
is an increase of voltage and current when the length is increased. With the
formula V=IR, the resistance is calculated and with the increase of the length,
there is an increase in the resistance.
Data Analysis
Evaluation
The battery pack is measured with a
multimeter to confirm its voltage for an accurate result. The length of the
wire is inaccurate due to the inaccuracy of identifying the point of the
cutting and the lacking of proper equipment to make a clean cut. Although the
graph is not plotted with a complete straight line, estimation is made where
the line is drawn through the average of two points, giving an accurate answer.
Things to Improve:
·
Using the multimeter instead of the
ammeter where the experiment will be simpler and more accurate
·
Using diagonal pliers to cut the wire
for its sharpness and accuracy in length
·
Usage of a variable resistor, as it
too uses the theory of increasing the length of the circuit to increase
resistance
Conclusion
The
hypothesis is valid where resistance is directly proportional to length. Hence,
R α L
Experiment 2
Design
Aim
To investigate the relationship
between resistance of a conductor and cross-sectional area of wire
Hypothesis
The larger the cross-sectional area
of the wire, the lower the resistance
|
Variables
|
Ways
|
|
|
Constant
|
The
current and voltage flowing through the circuit
|
By
using the same batteries with each of the experiments to ensure the constancy
of the voltage and current
|
|
Manipulated
|
The
cross-sectional area of the wire
|
Using different wires with
different diameters by identifying the SWG of the wire
|
|
Responding
|
The
resistance of the circuit
|
Calculate resistance by taking down
the voltage and current, substituting them into the formula V=IR
|
1. 1
ammeter
2.
2 crocodile clips (red & black)
3.
2 1.5V batteries
4.
1 1m SWG26 Nichrome wire
5. 1
1m SWG28 Nichrome wire
Procedure
1. Arrange
the apparatus accordingly to the circuit stated
2.
Complete the circuit with the SWG 26
1m Nichrome wire
3.
Note down the reading of the ammeter
4. Repeat
step 2 and 3 with the SWG 28 1m Nichrome wire
Safety
Procedure
1. Do
not connect the circuit by holding the wire and the Nichrome wire with hands
2. Use
low voltage batteries to avoid the danger of being electrified
Data
The following is a table regarding to the results of
the experiment
|
Diameter
(SWG)
|
Diameter
(mm)
|
Type
|
Length
(m)
|
Voltage
(V)
|
Current
(A)
|
Resistance
(Ohms)
|
|
SWG
26
|
0.457
|
Nichrome
|
1
|
3
|
0.18
|
16.67
|
|
SWG
28
|
0.376
|
Nichrome
|
1
|
3
|
0.16
|
18.75
|
Observation
There
is an increase of voltage and current when the diameter is decreased. With the
formula V=IR, the resistance is calculated and with the increase of the
diameter, there is an increase in the resistance.
Data Analysis
As you can see, the diagram displays on the
flow of electrons in the wire, with red being the ions and black ones are being
the electrons. With a bigger diameter, there will be more presence of ion
particles due to the more materials used. Therefore, more ions mean more
electrons can be transferred at a time, decreasing the resistance.
Evaluation
No resistors are used in this experiment,
causing the battery to short-circuit, draining all of its energy in just a
short amount of time. The battery was forced to be changed in order to carry on
the experiment.
A multi-meter should be used to measure the
resistant too for a more accurate answer as the reading on the ammeter keeps
jumping up and down making the results unreadable and inaccurate.
Conclusion
The
resistance inversely proportional to the cross-sectional area of wire,
therefore hypothesis is proven. Hence,
R α 1/A
Experiment 3
Design
Aim
To investigate the relationship
between resistance of a conductor and temperature
Hypothesis
The higher the temperature, the
higher the resistance
|
Variables
|
Ways
|
|
|
Constant
|
The
current and voltage flowing through the circuit
|
By
using the same batteries with each of the experiments to ensure the constancy
of the voltage and current
|
|
Manipulated
|
The
temperature of the wire
|
Changing the environment’s
temperature by using a Bunsen burner while comparing it to room temperature
|
|
Responding
|
The
resistance of the circuit
|
Calculate resistance by taking down
the voltage and current, substituting them into the formula V=IR
|
1. 1
ammeter
2.
2 crocodile clips (red & black)
3.
2 1.5V batteries
4.
1 1m SWG26 Nichrome wire
5.
1 1m SWG28 Nichrome wire
6. Bunsen
Burner
Procedure
1. Arrange
the apparatus accordingly to the circuit stated
2.
Complete the circuit with the SWG 26
1m Nichrome wire
3.
Burn the wire using the Bunsen burner
4.
Note down the reading of the ammeter
5. Repeat
step 2, 3 and 4 with the SWG 28 1m Nichrome wire
Safety
Procedure
1.
Do not connect the circuit by holding
the wire and the Nichrome wire with hands
2.
Use low voltage batteries to avoid
the danger of being electrified
3.
Be cautious while handling the Bunsen
burner
Data
|
Resistance (Ohms)
|
|||
|
Diameter
(SWG)
|
Type
|
Before
Heating
|
After
heating
|
|
SWG
26
|
Nichrome
|
16.67
|
16.87
|
|
SWG
28
|
Nichrome
|
18.75
|
19.05
|
Observation
There
is a slight increase of resistance after the temperature of the wire is
increased by the Bunsen burner. With estimation for the change of temperature
around 2000 degree Celsius, there is an increase of 0.2 ohms of resistance.
Data Analysis
There is an increase of resistance due to the
movement of particles reacting to the heat energy. When atoms are heated up,
they contain more energy causing the kinetic energy present inside them to
increase. The resistance is increased where the atoms are heated up, electrons
will have a harder time getting pass the atoms due to the increased of number
of collisions made.
With every temperature increase, there will
be always a constant increase in resistance due to the atoms. However, the
formula cannot be figured out and the data cannot be inputted into a graph due
to the inability to measure the temperature increase of the wire.
Evaluation
The battery pack is measured with a
multi-meter to confirm its voltage for an accurate result. The length of the
wire is inaccurate due to the inaccuracy of identifying the point of the
cutting and the lacking of proper equipment to make a clean cut. Although the
graph is not plotted with a complete straight line, estimation is made where
the line is drawn through the average of two points, giving an accurate answer.
Things to Improve:
·
Using the multi-meter instead of the
ammeter where the experiment will be simpler and more accurate
·
Using diagonal pliers to cut the wire
for its sharpness and accuracy in length
·
Usage of a variable resistor, as it
too uses the theory of increasing the length of the circuit to increase
resistance
·
The exact heat temperature of the
wire couldn’t be measured where expensive high-end equipment must be used in
order to carry out such tasks.
Conclusion
The
higher the temperature, the higher the resistance, therefore, the hypothesis is
proven.
Experiment
4
Design
Aim
To investigate the relationship
between resistance and the material of the wire
Hypothesis
The longer the length of the wire,
the higher the resistance
|
Variables
|
Ways
|
|
|
Constant
|
The
current and voltage flowing through the circuit
|
By
using the same batteries with each of the experiments to ensure the constancy
of the voltage and current
|
|
Manipulated
|
The
material of the wire
|
Identifying and changing the types wire
accordingly by their properties such as color, hardness and more.
|
|
Responding
|
The
resistance of the circuit
|
Calculate resistance by taking down
the voltage and current, substituting them into the formula V=IR
|
Apparatus
7. 1
ammeter
8.
2 crocodile clips (red & black)
9.
2 1.5V batteries
10.
1 1m Copper Wire
11. 1
1m SWG26 Nichrome wire
Procedure
5. Arrange
the apparatus accordingly to the circuit stated
6.
Complete the circuit with the
Nichrome wire
7.
Note down the reading of the ammeter
8. Repeat
step 2 and 3 with the copper wire
Safety
Procedure
3. Do
not connect the circuit by holding the wire and the Nichrome wire with hands
4. Use
low voltage batteries to avoid the danger of being electrified
Data
|
Diameter
|
Material
|
Length (m)
|
Voltage (v)
|
Current (A)
|
Resistance (Ohm) V=IR
|
|
SWG 26
|
Nichrome
|
1
|
3
|
0.18
|
16.67
|
|
SWG 26
|
Copper
|
1
|
3
|
11.627
|
0.258
|
Observation
The
resistance of Nichrome wire is higher than copper wire, with the formula V=IR,
the resistance of Nichrome wire is 16.67 ohms and the resistance for copper
wire is 0.258 ohms.
Data Analysis
Different types of materials have different
resistance, where they have different ways of transferring the electrons from
one another due to their electron alignment. From the table, the constant for
Nichrome is 1.1 x 10^-6 and copper is 1.7 x 10^-8.
Copper has less resistance than Nichrome where more energy is consumed
by resistance. Copper being cheap and easily accessible, is used frequently for
electrical purposes such as wiring due to its low resistance.
Evaluation
The battery pack is measured with a
multi-meter to confirm its voltage for an accurate result. The length of the
wire is inaccurate due to the inaccuracy of identifying the point of the
cutting and the lacking of proper equipment to make a clean cut. Although the
graph is not plotted with a complete straight line, estimation is made where
the line is drawn through the average of two points, giving an accurate answer.
Things to Improve:
·
Using the multi-meter instead of the
ammeter where the experiment will be simpler and more accurate
·
Using diagonal pliers to cut the wire
for its sharpness and accuracy in length
·
Usage of a variable resistor, as it
too uses the theory of increasing the length of the circuit to increase
resistance
Conclusion
Different types of material have different
resistance. The hypothesis is proven.
Overall Conclusion
·
R α L
·
R α 1/A
From these two relationships acquired from
the experiments, an equation can be created which can connect both of the two
stated relationships.
R=p (1/A )
This equation is acquired by using the
proportionate rule, where R α L is
equivalent to R=p (L) where p is a constant. The same applies to R α 1/A where
R= p(1/A). Both can be combined which forms the stated equation.
In conclusion, it is proven that factors
which affect the movement of electrons in atoms will affect resistance, where
the size, temperature, materials all affects the electrons.
Resistance can bring us advantages and
disadvantages too, where it can help us control the amount of current going
through while much energy loss occurred because of resistance. Therefore, I
hope that further research could be made to improve and advance in technology.
This was quite helpful for one of my tasks...thnx! :)
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