Conceptual Physics

10.8 You have ten 4.0 ȍ resistors. How can you create an equivalent resistance of 5.0 ȍ? (There is more than one correct

solution, and you do not have to use all the resistors.)

10.9 When the 10.0 ȍ resistor starts to dissipate

100 W of power, it will rupture. What minimum

emf can be applied to this circuit to cause the

resistor to rupture?

V

10.10Many lamps have a switch that lets you
choose three levels of brightness. The bulbs
in this type of lamp have not one but two
filaments inside, which are wired in parallel
and have their own switches. One of the
filaments is designed to give off more light
than the other when connected to the average
120 V emf provided by a wall outlet. In the
dimmest position, only the least bright
filament is on. In the next position, only the
brighter filament is on. In the brightest
position, both filaments are on. Suppose one of the filaments consumes 55.0 watts and the other consumes 70.0 watts. What
is their equivalent resistance in the brightest position (when both are turned on)?

ȍ

10.11You have 3 identical resistors. How many equivalent resistances can you create, using all three resistors?

1 2 3 4 5 6

10.12There are n identical resistors in a section of a circuit. The potential difference across this section of the circuit is ǻV. The
resistors can be placed either all in series, or all in parallel. (a) Which configuration "consumes" more power, series or
parallel? (b) By what factor must you multiply the power consumed by the low-power configuration to get the power
consumed by the higher-power configuration?

(a) Series Parallel

(b) 1/n 1/n^2 n n^2

10.13In parallel, two resistors have an equivalent resistance of 100 ohms. In series, they have an equivalent resistance of 625

ohms. (a) What is the resistance of the resistor with greater resistance? (b) The lesser resistance?

(a) ȍ

(b) ȍ

Section 11 - Interactive problem: a parallel circuit

11.1 Use the simulation in the interactive problem in this section to calculate the resistance of the unknown resistor in the parallel
circuit.

ȍ

Section 12 - Circuits with series and parallel wiring

12.1 Four identical 5.00 ȍ resistors are joined and

form the four sides of a square. (a) What is the

resistance between points A and B? (b) What

is the resistance between A and C?

(a) ȍ

(b) ȍ

Copyright 2007 Kinetic Books Co. Chapter 27 Problems^503