1. Verifying the Effect of Length
of a conductor to the Resistance
Vania Lundina – 11 Science
According to Ohm’s Law, the resistance of a conductor depends on its
material. From the formula R =  L / A, we can conclude that the
resistance of a conductor is directly proportional to its length, and is
inversely proportional to the cross-sectional area of the conductor
itself. The aim of this experiment is to verify the effect of length of a
conductor to its resistance.
My hypothesis would be the longer the material, the bigger the
resistance and the greater the cross-sectional area of the material,
the lower the resistance would be. The independent variable is the
length and thickness of the conductor. The dependent variable is the
voltmeter and ammeter reading to find the resistance, and the
controlled variable is the V from the power supply and the thickness
of the wire.
My experiment diagram would look like this:
A
V
= Resistance wire

2. The materials needed are:
1. Resistance wires of 10 cm, 15 cm, 20 cm, 25 cm, 30 cm and
35 cm.
2. Connecting wires.
3. Crocodile clips.
4. A voltmeter.
5. An ammeter.
6. A power supply.
Procedures:
1. Set up the circuit with a 10 cm resistance wire like the diagram
shown above.
2. Turn the power supply on; set it into 3 V.
3. Check the reading on the ammeter and voltmeter.
4. Measure the resistance of the resistance wire using the formula
V = I R.
5. Do the same step for the resistances wire 15 cm, 20 cm, 25
cm, 30 cm and 35 cm.
In doing this experiment, the accuracy of the length of resistance wire
must be considered. To avoid any unexpected or inaccurate data, the
experiment will be repeated 3 times. I will take the average of the
three data.

3. Result in table form:
No. Length of Ammeter Voltmeter Resistance Ave.
Resistance Reading/A Reading/V from R/
wire/cm R = V/I
TRIAL
1 2 3
1 10 1,8 1,3 1,6 0,7 0,7 1,0
2 15 1,5 1,6 1,1 0,9 0,9 1,0
3 20 1,4 1,7 1,2 1,2 1,2 1,2
4 25 1,2 1,8 1,5 1,5 1,5 1,5
5 30 1,1 2,0 1,8 1,9 1,7 1,7
6 35 1,0 2,1 2,1 2,1 1,9 2,0
Analysis and conclusion:
Some data form my first, second and third trial showed different
readings of ampere and volt. This difference might be caused by the
inaccuracy of the length of the resistance wire. But the average value
somehow proves the formula R =  L / A, where the length of the
resistance wire does affect the resistance of the conductor. So my conclusion
is, the longer the wire, the bigger the value of resistance would be.