Ohm's Law
Aim:To prove ohms' law, and to study the relationship between current
and potential difference (voltage).
Hypothesis: The current flowing through a metal wire is proportional
to the potential difference across it (providing the temperature is
constant).
Apparatus:
1. Power Supply
2. Variable resistor
3. Ammeter
4. Voltmeter
5. Resistors
6. Electric wires
Diagrams:
=========
R1: R2:
R1 + R2 (in series): R1 + R2 (in parallel):
Method:
1. Set up the apparatus 4 times as shown in the diagrams above
2. Set the power supply to 6v
3. Set the variable resistor to maximum resistance
4. Switch on the power and note the ammeter and voltmeter readings
5. Reduce the resistance of the variable resistor
6. Repeat steps 4, and 5 until at least five 8 sets of readings have
been obtained
7. Change the setting of the apparatus as shown in the diagrams
above, and perform steps 2 - 6 with each setting of apparatus
Results:
· Table of results for one resistor of 12Ω
------------------------------------------
Current (A)
Voltage (v)
0.18
2.18
0.20
2.30
0.22
2.52
0.24
2.79
0.26
3.02
0.28
3.39
0.30
3.62
0.38
4.41
· Table of results for one resistor of 10Ω
Current (A)
Voltage (v)
0.18
1.80
0.20
2.06
0.22
2.23
0.24
2.46
0.26
2.67
0.28
2.95
0.30
3.19
0.39
3.99
· Table of results for two resistors in series of 10Ω + 12 Ω = 22Ω
5. A second test tube was then filled with water and placed in a test
3.) Divide your 30g of white substance into the 4 test tubes evenly. You should put 7.5g into each test tube along with the water.
1. Decide on a range of temperatures from 5 °C to 35 °C to be tested.
= I have decided to produce a step-by-step guide for each experiment. just to ensure that when we actually come to conducting the practical work, it runs flawlessly. This will also help us conduct fairer tests. as we will be following the same set of steps each time we collect a result.
I would also use what I have concluded at the end of the experiment to
Method:I am going to do 5 tests & each test will be performed 3 times
of each in each test tube. (Table below showing how I am going to make
I chose to take 7 readings as 7 is an easy number to work with to
5) I will repeat the experiment 2 more times, so I have a total of
have to be across the wire and not just anywhere in the circuit so it
4. Put each group of potato discs in one of the 6 test tubes and watch
An Investigation into the Relationship Between the Resistance of a Wire and Its Diameter and Length
8) Repeat, till there is no more mass on the elastic. Measure the length of the elastic.
1. Label the test tubes A, B, C, and D. label the staining dishes B,
results are shown on page . For each reading I will repeat it 3 times