- Level: International Baccalaureate
- Subject: Physics
- Word count: 2560
Investigating resistors
Extracts from this document...
Introduction
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:
Dependent | Independent | Controlled |
Voltage and current in each resistors | Resistors | Amperemeter and voltmeter used |
Potential difference in each resistors measured by using voltmeter | Number of resistors in circuit | Temperature is kept the same |
Potential difference (V) from power supply | Constantly used amperemeter in series connection and set up to always get in positive current | |
Values of resistance in resistors |
Apparatus
Items | Quantity | Accuracy |
Power Supply | 1 | |
Voltmeter | 1 | |
Amperemeter | 1 | |
Resistor | As needed | |
Connector table or wire | As needed | |
Circuit breadboard | As needed |
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
Middle
4.7×10
4.7×10
1.41×10
6.36
0.45
6.345
6.345
6.345
Table3. Table of resistance, voltage, and current
R1() ΔR ±0.5% | R2 () ΔR ±0.5% | R3() ΔR ±0.5% | Rt() ΔR ±0.5% | Vs (V) ΔV ±0.005v | Current I (mA) ΔI±0.5 mA | V1 (V) ΔV ±0.005v | V2 (V) ΔV ±0.005v | V3 (V) ΔV ±0.005v |
820 | 820 | 6.36 | 7.7 | 6.314 | ||||
820 | 820 | 1640 | 6.36 | 3.9 | 6.396 | 6.396 | ||
820 | 820 | 470 | 2130 | 6.36 | 3.0 | 6.390 | 6.390 | 6.390 |
Table4. Table of resistance, voltage, and current
R1() ΔR ±0.5% | R2 () ΔR ±0.5% | R3() ΔR ±0.5% | Rt() ΔR ±0.5% | Vs (V) ΔV ±0.005v | Current I (mA) ΔI±0.5 mA | V1 (V) ΔV ±0.005v | V2 (V) ΔV ±0.005v | V3 (V) ΔV ±0.005v |
100 | 100 | 6.36 | 6.36 | 6.36 | ||||
100 | 820 | 920 | 6.36 | 6.90 | 6.35 | 6.35 | ||
100 | 820 | 680 | 1600 | 6.36 | 4.00 | 6.40 | 6.40 | 6.40 |
Table5. Table of resistance, voltage, and current
R1() ΔR ±0.5% | R2 () ΔR ±0.5% | R3() ΔR ±0.5% | Rt() ΔR ±0.5% | Vs (V) ΔV ±0.005v | Current I (mA) ΔI±0.5 mA | V1 (V) ΔV ±0.005v | V2 (V) ΔV ±0.005v | V3 (V) ΔV ±0.005v |
820 | 820 | 6.36 | 7.7 | 6.314 | ||||
820 | 820 | 1640 | 6.36 | 3.9 | 6.396 | 6.396 | ||
820 | 820 | 820 | 2460 | 6.36 | 2.6 | 6.396 | 6.396 | 6.396 |
EM-6: Parallel
Table1. Table of resistance, voltage, and current
R1() ΔR ±0.5% | R2 () ΔR ±0.5% | R3() ΔR ±0.5% | Rt() ΔR ±0.5% | Vs (V) ΔV ±0.005v | Current I (mA) ΔI±0.5 mA | I1 ΔI ±0.005 mA | I2 ΔI ±0.005mA | I3 ΔI ±0.005mA |
4.7×10 | 4.7×10 | 6.36 | 1.3 | 1.3 | ||||
4.7×10 | 2×10 | 1402 | 6.36 | 4.54 | 1.3 | 3.2 | ||
4.7×10 | 2×10 | 6.8×10 | 1163 | 6.36 | 5.5 | 1.3 | 3.2 | 0.93 |
Table2. Table of resistance, voltage, and current
R1() ΔR ±0.5% | R2 () ΔR ±0.5% | R3() ΔR ±0.5% | Rt () ΔR ±0.5% | Vs (V) ΔV ±0.005v | Current I (mA) ΔI±0.5 mA | I1 ΔI ±0.005 mA | I2 ΔI ±0.005mA | I3 ΔI ±0.005mA |
1.2×10 | 1.2×10 | 6.36 | 0.53 | 0.53 | - | - | ||
1.2×10 | 2×10 | 7.5×10 | 6.36 | 0.85 | 0.53 | 0.32 | - | |
1.2×10 | 2×10 | 1×10 | 5454.54 | 6.36 | 1.17 | 0.53 | 0.32 | 0.32 |
Table3. Table of resistance, voltage, and current
R1() ΔR ±0.5% | R2 () ΔR ±0.5% | R3() ΔR ±0.5% | Rt () ΔR ±0.5% |
Conclusion
From the result that was gotten from this experiment and the results have been calculated using formula as stated before, there was slightly difference. This might be was caused by power loss and resistance of the wire. Other possibility was because the resistance of ampere meter was zero and that’s infinite as voltmeter which will never be gotten in the results. The difficulties in this experiment were very usual in setting up the circuit especially in setting in parallel and combination circuit. We didn’t usual to do this kind of experiment. It was also making some mistake in conducting the experiment with a lot of variants or changes. In this experiment, we didn’t usual to read how many ohms in the resistor because we weren’t expert in this experiment.
Overall, this experiment is success with the result of calculation. In the results which slightly difference that was because of power loss. My suggestion is to use a small wire to make less chance to the power loss by reducing resistance from large area. The other suggestion is to be more careful and practice better in conducting this kind of experiment and learn again about how to set up the circuit and read each resistor. Those suggestions will improve the results and make more trials because faster and longer time. By doing this experiment, there should be an effect to our experience in doing all kind of electro. My suggestion may improve a lot if we will do this kind of experiment again.
This student written piece of work is one of many that can be found in our International Baccalaureate Physics section.
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