Electrical experiments usually involve the reading of meters such as the voltmeters shown. a. What is the reading shown by each voltmeter, and the uncertainty in each reading? b. The voltmeters show the readings obtained when they were connected across two wires that were identical apart from their different lengths. The current in each wire was 0.500 A and the

Chapter 32, Exam-style Questions #4

Electrical experiments usually involve the reading of meters such as the voltmeters shown.

a. What is the reading shown by each voltmeter, and the uncertainty in each reading?
b. The voltmeters show the readings obtained when they were connected across two wires that were identical apart from their different lengths. The current in each wire was 0.500 A and the length l of the wire was 30.0 cm in the right diagram and 50.0 cm in the left diagram. Use the scale readings to test the hypothesis that the resistance R of the wire is proportional to length l. Consider the effect of the uncertainties on your conclusion.