Practical Assessment - DCP CE

Resistance of a wire

Design

Research Question: Find the relationship between your chosen independent variable and the resistance of a uniform wire.

Independent variable: Length

Dependant variable: Resistance

Control variables: Type of wire, battery pack etc.

Equipment:

Constantan Wire (of different diameters)VoltmeterAmmeterMicrometer screw gaugeMeter ruleWire cuttersCroc clipsConnecting wiresLabels

Plan:

Decide upon your independent variable. If you are confused see the teacher. Set up the test circuit as shown above. Take readings and record in an appropriate way. For safety reasons do not

exceed a current of 1A. Repeat readings if possible. Calculate the resistance of the wire. Plot a suitable graph to answer the research question. If necessary manipulate your data to try to get a straight line graph (use excel) All your work must be printed out for submission in hard copy next lesson.

GCSE Physics 1

In this investigation you will be assessed on the criteria data collection and processing and conclusion and evaluation.

Resistance = Voltage Current

A

V

The wire

Safety

If the wire exceeds 1A it can get hot and could burn you.

DO NOT EXCEED A CURENT OF 1AMP.

Practical Assessment - DCP CE

Assessment Criteria

Data Collection and Processing

Aspect 1: data collection

Repeat 1 Repeat 2Length /cm

Voltage/V Current /A

Voltage/V Current /A Voltage Average

Amps Average Resitance /Ω (Ohms)

10 0.01 0.06 0.01 0.06 0.01 0.06 0.16666666720 0.1 0.06 0.02 0.06 0.06 0.06 130 0.03 0.06 0.03 0.06 0.03 0.06 0.540 0.03 0.06 0.03 0.06 0.03 0.06 0.550 0.04 0.06 0.04 0.06 0.04 0.06 0.66666666760 0.07 0.06 0.07 0.06 0.07 0.06 1.16666666770 0.06 0.06 0.05 0.06 0.055 0.06 0.91666666780 0.08 0.06 0.06 0.06 0.07 0.06 1.16666666790 0.07 0.06 0.07 0.06 0.07 0.06 1.166666667

100 0.08 0.06 0.08 0.06 0.08 0.06 1.333333333

Aspect 2: processing raw dataAspect 3: presenting processed data

GCSE Physics 2

Practical Assessment - DCP CEConclusion and Evaluation

Aspect 1: concluding.

State the relationship between the dependant and independent variable.

What evidence do you have that suggests the relationship you have chosen? Remember is there a straight line? Is there a proportionality or direct proportionality?

Aspect 2: evaluating procedure

Use a few lines to discuss the quality of your results. Discuss the weaknesses in your experiment. How big a problem was each weakness?

Aspect 3: improving the investigation

Discuss how you would improve the experiment. State exactly how each improvement will be implemented.

Conclusion and Evaluation

Aspect 1: concluding.

State the relationship between the dependant and independent variable.As the length of the wire increases, the resistance of the wire also increases. There is a proportional relationship between the dependant and the independent variable.The line and results are mostly in a positive correlation.

Aspect 2: evaluating procedure

The quality of our results was very inaccurate; there were a lot of anomalies in our results and the results themselves fluctuated a lot so the data was scattered all over the chart. The weakness of our experiment was our inexperience doing this practical so our method of handling it was very clumsy. We also had the limitation with the use of the Glider as when we applied too much pressure when calculating the results fluctuated and despite repeats the results was still inaccurate. This had a huge impact of our results which were all over the graph.

Aspect 3: improving the investigationI would improve the experiment by using more accurate equipment besides the glider; I also would use the computer to record the results, as there were a lot of human errors when we did it. We should also have more repeats as we only did it twice and more repeats means more points on our results and more accurate results.

GCSE Physics 3

Practical Assessment - DCP CE

GCSE Physics 4