Chapter 1

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College Physics
Alan Giambattista
Betty Richardson
Robert Richardson
4th edition
Chapter 18
Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.
Question 1
In the circuit shown, the current flows
counterclockwise (CCW). This means
A) the electrons flow CCW.
B) the electrons flow CW.
C) the protons flow CCW.
D) the protons flow CW.
Question 2
A wire of length L and cross sectional area A
has a resistance R. What would be the
resistance of two identical wires placed endto-end?
A) 1/4 R
B) 1/2 R
C) R
D) 2R
E) 4R
Question 3
A wire of length L and cross sectional area A
has a resistance R. What would be the
resistance of two identical wires in parallel?
A) 1/4 R
B) 1/2 R
C) R
D) 2R
E) 4R
Question 4
A wire of length L and diameter D has a
resistance R. What would be the
resistance of a wire with length L and
diameter 2D?
A) 1/4 R
B) 1/2 R
C) R
D) 2R
E) 4R
Question 5
A current I flows through a resistor R that is
held at a constant potential V. If the
resistance is doubled, the new current is
_____.
A) I/2
B) I
C) 2I
Question 6
Given the circuit below, what can you say
about the current flowing into points A, B, C,
and D?
A) IA > IB > IC > ID
B) IA = ID > IB = IC
C) IA < IB < IC < ID
D) IA = IB = IC = ID
Question 7
Given the circuit below, what can you say
about the voltage measured at points A, B,
C, and D?
A) VA > VB > VC > VD
B) VA = VB = VC = VD
C) VA = VB > VC = VD
D) VA < VB < VC < VD
Question 8
A circuit consists of three resistors connected
in parallel across a potential V. If R1 > R2 >
R3, which of the following is a true statement
about the current flowing through each
resistor?
A) I1 > I2 > I3
B) I1 = I2 = I3
C) I1 < I2 < I3
D) Cannot be determined.
Question 9
A circuit consists of three resistors connected
in series across a potential V. If R1 > R2 >
R3, which of the following is a true statement
about the current flowing through each
resistor?
A) I1 > I2 > I3
B) I1 = I2 = I3
C) I1 < I2 < I3
D) Cannot be determined.
Question 10
Your portable radio requires an emf of 24 V.
You have a box of 6 V batteries. To attain
the required emf, you should
A) connect two batteries in series to two
batteries in parallel.
B) connect three batteries in parallel in
series with a fourth battery.
C) connect four batteries in parallel.
D) connect four batteries in series.
Question 11
The electric company wants to send power to a
remote substation and must connect several
power lines to reach it. To reduce power
losses in the wire, the electric company
should
A) use a very high voltage and low current.
B) use a low voltage and very high current.
C) not worry about the voltage or current as
the power loss will be the same.
Question 12
In the circuit shown below, two capacitors in parallel
are connected to a battery through a resistor.
Initially the switch is open. When the switch is
closed, the current through the resistor is
A) at a maximum
and decreasing.
B) at a minimum
and increasing.
C) at a minimum and decreasing.
D) at a maximum and increasing.
Question 13
In this circuit, two capacitors in parallel are
connected to a battery through a resistor.
Initially the switch is open. A long time after
the switch is closed, the current through the
resistor is
A) 12.5 A
B) 12.5 mA
C) 0
D) 80 A
Question 14
Rank the drift velocity of the electrons in each
of the following copper wires (each has the
same potential difference across the ends).
L
L
1
A
2
2L
2L
2A
A) v2 > v1 = v4 > v3
B) v3 > v4 = v1 > v2
3
A
4
2A
C) v2 = v1 > v4 = v3
D) not enough information
Question 15
How much work is done by a 12.0-V ideal
battery that supplies a 5.00-A current for
30.0 minutes?
A) 1800 J
B) 1.08 x 105 J
C) 4320 J
D) 750 J
Question 16
As the temperature increases, the resistance of
a resistor
A) decreases because the electrons are
more mobile and have greater velocities.
B) increases because electrons collide more
frequently, slowing their drift velocity.
C) is unchanged since temperature doesn't
affect the number of charge-carrying
electrons.
Question 17
A copper wire is an Ohmic resistor. The
resistance is given by the slope of the in in
which of the following graphs?
I
I
I
DV
DV
A
B
I
DV
C
DV
D
Question 18
Two 12-Ω resistors are connected in series.
The equivalent resistance is
A) less than 12 Ω.
B) equal to 12 Ω.
C) greater than 12 Ω.
Question 19
Two 12-Ω resistors are connected in parallel.
The equivalent resistance is
A) less than 12 Ω.
B) equal to 12 Ω.
C) greater than 12 Ω.
Question 20
You are designing the wiring for your new
house. You would like for a single switch to
turn on three floodlights. To get the greatest
illumination, you should wire the lights in the
circuit in
A) series.
B) parallel.
C) it won't matter since the bulbs are a fixed
wattage.
Answer Key – Chapter 18
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
B
D
B
A
A
B
C
C
B
D
11.
12.
13.
14.
15.
16.
17.
18.
19.
20.
A
A
C
B
A
B
D
C
A
B

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