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Voltmeters and Ammeters

PHY 201 & 231

Lab PDF 1
Lab PDF 2

Based on Loyd #31. In this experiment, students will take measurements of circuits with galvanometers. From the measurements, the students will determine the internal resistance of the galvanometer, the current sensitivity. The students will also turn the galvanometer into a voltmeter by putting it in series with the correct resistance and into an ammeter by putting it in parallel with the correct resistance.


Name Location Quantity
Galvanometer JE-105A-S51 1 per table
Power Supply, Extech (Model #382213) JE-105A-X12/13 1 per table
Resistors, 330 Ohms JE-105A -X40 1 per table
Multimeter, Digital, Sperry DM5300 - Battery JE-105A- D101 1 per table
Resistance, Decade Box (Central Scientific Co. Cat JE-105A-S47 1 per table
Wire, Banana Patch Cords, Hookup Leads JE-Lab Rooms-ByChalkboard 4 per table
Tools, Wire Cutter JE-105A-Toolbox S8 1 per room
Clips, Alligator JE-105A-S58 4 per table
Multimeter, Digital, Extech EX420 - Battery JE-105A-D103 1 per table


Use the center screw to zero all galvanometers before the lab. Also be sure to test the multimeters and power supplies. Put out the Extech power supplies. If there are not enough, use the Sargent-Welch power supplies. The Loyd lab manual calls for resistance boxes between 2500 and 3500 ohms. Make sure that the resistance boxes put out have that range.

Have available a spool of #28 copper wire (located on S69) and wire cutters. Because of their size, the resistors should be kept on the instructor's table.

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Item modified on 2020-02-17 11:47:48 by llanosn2.