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RC Time Constant

PHY 201 & 231

Lab PDF 1
Lab PDF 2

Based on Loyd #33. In this experiment, students will use a series combination of a power supply, a capacitor, and resistors to determine the RC time constant and measure voltage across a resistor as a function of time. The students will determine the RC time constant of two series RC circuits. From measurements made on a series RC circuit, the value of an unknown capacitor will be determined. The value of an unknown resistor will be determined from an RC circuit in parallel with a voltmeter.


Name Location Quantity
Timer, - MyChron, Battery JE-105A-D62 1 per table
Wire, Banana Patch Cords, Hookup Leads JE-Lab Rooms-ByChalkboard 6 per table
Multimeter, Digital, Sperry DM5300 - Battery JE-105A- D101 1 per table
Power Supply, Extech (Model #382213) JE-105A-X12/13 1 per table
Kirchhoff's Law Circuit Boards JE-105A-S55, S56 1 per table
Multimeter, Digital, Extech EX420 - Battery JE-105A-D103 1 per table
Multimeter, Digital, Tektronix DM253 - Battery JE-105A-S59 1 per room
Resistor, 3.9 Megaohms JE-105A-X40 0 per table
Clips, Alligator JE-105A-S58 2 per table


1.) Put out the Extech power supplies. If there are not enough, use the Sargent-Welch power supplies.
2.) Put out the smaller Kirchhoff's Law Circuit boards found on S56 in place of the RC Circuits boards found on S57.
3.) 10uF capacitors are kept in a drawer found on shelf X40. These capacitors are only needed if one on a Kirchhoff's Law circuit board is broken or has become detached.
4.) Do not forget the capacitance meter.
5.) Check with supervisor or instructor whether the extra 3.9 MΩ resistors should be used, in which case place the resistor on the table with an alligator clip attached to each end.

This lab requires laptops. The computer cart containing the laptops can be wheeled by faculty into the lab room.

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Item modified on 2017-03-31 17:49:19 by damicoa6.