Investigating resistors
Aim:
- EM-5: to investigate the effect of potential difference on current in a carbon resistor
- EM-6: to investigate how the addition of resistors in parallel or series affects the voltage and current in a circuit
- EM-7: To determine the total effective resistance of a combination of resistors in series and parallel
- From all EM-5, EM-6 and EM-7 are aimed to compare the results collected from the data (current and potential difference)
Hypothesis:
When we put all resistors together in series it will has greater effectiveness than in parllel because circuit all resistors will have same current but they will have different voltage. In parallel, resistors will have same voltage but different in current. In total series (R1+R2+R3) and in total parallel (). To calculate voltage = current (I) vs resistance (R)
Variables:
Apparatus
Methods:
EM-5:
- Connect the circuit as chosen
- Set power supply to 3 v and measure the potential difference and current in the circuit
- Change the supplied voltage to 6, 9, and 12 v and measure potential difference and current
- Repeat the above for some trials
EM-6: parallel
EM-6: series
EM-7:
EM-6:
- Resistors in series
- Set up all materials as shown in diagram
- Connect a circuit with one unknown resistor, ampere meter, and volt meter and power supply. Turn power supply on and find potential difference and current
- Record results in table
- Add second resistor in series with the first. Measure the current and total potential difference and compare the results
- Then 3rd resistor in series with the first two
- Find the current and potential difference for each resistor.
- Record this last of results
- Resistors in parallel
- Set up all materials as shown in diagram
- Connect a circuit with one unknown resistors, ampere meter, and voltmeter and power supply, turn power supply (6 volt) on and find potential difference and current
- Add the second resistor to the circuit, in parallel with the first. Measure total potential difference in the circuit, total current across both resistors, and the current and potential difference for each resistor.
- Record these results
- Finally, add third resistor, in parallel with the first two. Once again, measure the total potential difference for each resistor.
- Record the last set of results