Physics Lab: Resistance is Futile! (DCP, CE) Write a lab report including the following: Research Question: How does the resistance of a conductor (a pencil lead) depend on the length of the conductor? Variables: Independent: length Dependent: Resistance Materials: Ohm-meter, mechanical pencil lead Procedure: Use the ohmmeter supplied to measure the resistance of a pencil lead of some easily handled length. Start with the test leads as close together as possible, and measure the resistance. Note the uncertainty in the resistance reading (how much does it fluctuate by? +/- 0.1 ? +/- 0.5 ?). Note also the uncertainty in your length measurements (+/- 1 cm? +/- 1 mm?). Include these in your data tables and subsequently on your graphs as error bars. Take several readings at each length. Data tables: Include units, labels, uncertainties in both R and L for all data. Graphs: Which variable goes on which axis? Include error bars for both R and L. Graph the data and draw a best fit line, and then a maximum possible slope line and a minimum possible slope line. Calculate the slopes of each to obtain an average slope and an uncertainty value. Consult your teacher and old lab/worksheet packets showing what is required for obtaining a maximum score for the IB DCP criteria. Conclusion & Evaluation Answer the question regarding the relationship between your variables. Does your graph what might have been expected from your study of current electricity? Discuss possible errors or uncertainties; explain what you could do to improve your lab procedure or results in a meaningful way.