Ammeters and Voltmeters
Part of the Electricity and Magnetism section of Coddy's Physics journey. Lesson 28 of 51.
An ammeter goes in series and has almost no resistance. A voltmeter goes in parallel, across what it measures, and has a very large resistance.
Ideal meters change nothing. A voltmeter whose resistance is near the resistor's is another resistor in parallel, and its reading drops.
Challenge
An ideal 9 V battery drives a current through a 3 Ω and a 6 Ω resistor in series. An ideal voltmeter is across the 6 Ω resistor. What does it read? Call the reading V_2.
Try it yourself
Test yourselfThis lesson includes a short quiz. Start the lesson to answer it and track your progress.
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