Ohm's Law Lab
Purpose:
You will build circuits using variable and fixed resistors.
You will measure current when resistance is changed.
You will measure and graph change in voltage when current is changed.
You will use your data and graph to determine the relationship between voltage, current and resistance.
Materials: Multimeter, wires, battery, resistors, potentiometer(variable resistor)
You will build circuits using variable and fixed resistors.
You will measure current when resistance is changed.
You will measure and graph change in voltage when current is changed.
You will use your data and graph to determine the relationship between voltage, current and resistance.
Materials: Multimeter, wires, battery, resistors, potentiometer(variable resistor)
![Picture](/uploads/1/1/1/4/1114892/published/screen-shot-2017-02-01-at-8-10-36-am_1.png)
Procedure: Part 1
- You will now use the potentiometer AND a green fixed resistor. Measure the resistance of ONLY your fixed resistor (place each lead on each end of the resistor). Record this value. PAY CLOSE ATTENTION TO YOUR UNIT on the meter. This will remain constant throughout the lab.
- Build the circuit on the right. Turn the potentiometer all the way to one side (as though it was all the way off). This will be your first setting where you will collect current and voltage.
- Measure the current through the circuit, and the voltage across the resistor. Record the values in a table.
- Turn the potentiometer knob and change the setting slightly.
- Measure the current and voltage again (you do not need to measure resistance across the potentiometer; you've already measured the resistor in step 1.)
- Repeat steps 4 & 5 for FIVE settings of the potentiometer. Record all values in a data table.
Analysis: (Answer, then upload photos of your data table, graph, and analysis questions to Edmodo)
- How does changing voltage affect current?
- Graph the data. Put voltage on the y-axis and current on the x-axis. (Remember to label axes and title your graph.) Upload a photo of your graph to Edmodo when done.
- Calculate the slope of the graph.
- Compare the slope you calculate to your data. Explain in a paragraph how your slope and data are or are not related and give data/calculations to support your claim.