Chapter 27 Problems
Conceptual Problems
C.1 A cheap flashlight is dropped into seawater. It is "short-circuited". What does this expression mean?
C.2 Why do batteries rated at the same emf sometimes differ so much in size? For example, consider a 1.5 AA penlight battery
compared to a D size battery.C.3 Why would a voltmeter with a low amount of resistance be a mediocre tool?
C.4 Consider a circuit containing a battery and several resistors. You measure the current flowing out one end of the battery, and
also measure the current entering the other end. Do you expect these measurements to be the same or different? Explain.
The same DifferentC.5 A battery is connected to either (1) three 5 ȍ resistors wired in series or (2) one 10 ȍ resistor. Which configuration will have
the most current flowing through it?
Configuration (1) Configuration (2)C.6 You have five identical light bulbs. You build one circuit with a battery and two light bulbs in series and build another circuit
with an identical battery and three light bulbs in series. The circuits are otherwise identical. In which circuit do you expect the
light bulbs to shine brighter? Explain.
i. Circuit with two light bulbs
ii. Circuit with three light bulbsC.7 Four 1.5 V batteries wired "in parallel" power an electronic device. If all but one of the batteries are removed, under what
circumstances (if any) will the device continue to function normally?
C.8 Are the light fixtures in a typical building wired in series or in parallel? How do you know?
Series ParallelC.9 In some strings of holiday lights, especially cheaper or older ones, if one light "burns out", all the other lights in the string also
go dark. (a) Are these types of lights wired in series or parallel? (b) Why does one light burning out cause the rest to go dark?
(a) Series Parallel
(b)
C.10Why might an engineer design a circuit with components in parallel?
C.11(a) Which resistors in the diagram are wired in
series? (b) Which are wired in parallel?
(a) R 1 and R 2 are in series
R 1 and R 3 are in series
R 2 and R 3 are in series
(b) R 1 and R 2 are in parallel
R 1 and R 3 are in parallel
R 3 is in parallel with the combination of
R 1 and R 2
C.12(a) Which resistors are in series? (b) Which
are in parallel?
(a) R 1 is in series with R 2
R 1 is in series with R 3
R 1 is in series with the combination of
R 2 and R 3
R 2 is in series with R 3
(b) R 1 is in parallel with R 2
R 1 is in parallel with R 3
R 1 is in parallel with the combination of
R 2 and R 3
R 2 is in parallel with R 3