Resistor+Lab+-+Peter,+Joey,+Amir

Title of Lab:

Researchers:Peter the MagniFabulouth, CanguroPequeno, A mirror

Research Question:What is the relationship between the voltage across an Ohmic device and the current flowing through the device.

Research: In an electric circuit, the current is constant throughout, but the voltage changes when the current passes through something with resistance. By measuring the current in a circuit and the voltage drop across a resistor, we should be able to find if there is a relationship between the two and what the relationship is.

Hypothesis: As the current passing through a resistor increases, the voltage difference across the resistor will increase as well. The current will be directly proportional to the voltage difference.

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Materials: Ammeter, Voltmeter, Volt Box, resistor, copper wires

Procedure: 1. Calibrate all instruments (and set up Multimeter as a voltmeter). 2. Create a circuit between the volt box and the ammeter, with a resistor leaving the ammeter. (Figure above) 3. Connect the voltmeter to either sides of the resistor. This will measure the difference in voltage caused by the resistor. 4. Increase the current using the volt box. 5. Measure the difference from both ends from the resistor. 6. Repeat 4 and 5. (and then record)

Data:



Data Analysis:



y= 81x + .77 The data shows that the voltage difference is directly proportional to the current. Though it should, the line does not start at (0,0) because the line of best fit that Excel found does not pass through it. The slope is most likely the resistance of the Ohmic device used in the experiment. We had a percent error of 2%.

Conclusion: The data supports the hypothesis, which is, the voltage difference is directly proportional to the current. We believe that the resistance inside the Ohmic device determines how many volts are lost per amp of current. Our error was due to the analog display on the ammeter which was hard to read accurately. For better results, an ammeter with a digital display should be used instead of the ones we were given.