A Simple Electrical Circuit

Purpose:

To study the resistor-capacitor electric circuit.

Description:

This lab begins with an introduction of the elements of the R-C circuit. This includes discussions on the change in voltage across a resistor with resistance R and on the change in voltage across a capacitor with capacitance C. The differential equation governing the R-C circuit is developed from Kirchhoff's Loop Law.

Students are asked to construct a R-C circuit using a 22 Kilo-ohm resistor and a 400 microfarad capacitor. Using MBL equipment they collect data on the amount of charge in the circuit and the potential difference across the capacitor.

They are asked to write a report on their findings. This report should include

• Graphs of the original MBL data, the regression analysis, and the overlay graphs showing the exponential fit.
• Some error analysis.
• The MathCAD/Maple V worksheet.

Materials Needed:

• MBL with Voltmeter and Ammeter probes.
• A 22 Kilo-ohm resistor.
• A 400 microfarad capacitor.
• Several wires.
• Power source between 3 and 10 Volts.

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