PHY222, Elements of Physics II
Ohm's Law, 25 January 2008
Items for Theory section of reports:
- State and describe Ohm's law for resistors in electric circuits.
- What formula describes how to combine resistors in series? Why?
- What formula describes combining resistors in parallel? Why?
- Describe the proper way to place a voltmeter into a circuit; also describe the proper placement of an ammeter.
In your explanations, look for what physical quantity remains constant throughout a series circuit,
and what remains constant in a parallel circuit. Chapter 17 in the textbook has useful information about
resistors and Ohm's law; chapter 18 explains how to obtain the combination formulas. As a bridge from
where the lecture is to the concepts the lab introduces, chapter 16.8 has analogous information
about how to combine another kind of circuit element, capacitors - possibly helpful.
There is a computer simulation, cut from the lab period, whose procedure is found at
Ohm's Law - Simulation. You can look over that and play with the computer program, too, for further background.
Comments on the Procedure, UPDATED 1/22:
The work for the Ohm's Law lab is split over the next two weeks. There is a write-up
for the first week's procedure found at Ohm's
Law - Light Bulbs.
The second week's procedure (that for 1 February) is found at
Ohm's Law - Series and Parallel Resistors.
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