N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1
Edition) By Douglas C. Giancoli (Test Bank All Chapters, 100% Original
N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1
Verified, A+ Grade) (Chapters 21-35) Answers At The End Of Each Chapter
N1 N 1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1
Chapter 21
N1
MULTIPLE N 1 CHOICE. N 1 Choose N1 the N1 one N 1 alternative N1 that N 1 best N1 completes N1 the N1 statement N1 or N1 answers N1 the
N1 question.
1) N 1
1) Internal battery resistance: In the figure, when the terminal voltage Vab of the
N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1
battery is
N1 equal to 20 V, how much current passes through the
N1 N 1 N 1 N 1 N 1 N 1 N 1 N 1 N 1 N 1 N 1
battery, including its direction?
N 1 N 1 N 1 N 1
A) 6 N1 A, N1 from N1 a N1 to N1 b
B) 5 N1 A, N1 from N1 a N1 to N1 b
C) 4 N1 A, N1 from N1 b N1 to N1 a
D) 5 N1 A, N1 from N1 b N1 to N1 a
E) 4 N1 A, N1 from N1 a N1 to N1 b
2) Internal battery resistance: The emf and the internal resistance of a battery are as2)
N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N 1
N1shown
in the figure. When the terminal voltage Vab is equal to 17.4 V, what is the
N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1
N1current throug battery, including its direction?
N1 N1 N1 N1 N1
A) 6.8 A,
N1 N1from N1 b N1 to N1 a
B) 8.7 A,
N1 N1from N1 b N1 to N1 a
C) 16 N1 A, N1 from N1 b N1 to N1 a
D) 6.8 A,
N1 N1from N1 a N1 to N1 b
E) 8.7 A,
N1 N1from N1 a N1 to N1 b
3) Current density: A proton beam that carries a total current of 1.3 mA has 10.0
N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N 1 N1
1
,mm diameter. The current density in the proton beam increases linearly with
N 1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 3) N 1
distance from
N1 the center. This is expressed mathematically as J(r) = J0
N1 N 1 N1 N1 N1 N1 N1 N1 N1 N1 N1
(r/R), where R is the radius of the beam and J0 is the current density
N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1
N1
N1 N1 N1
N1at the edge. Determine the value of J0.
N1 N1 N1 N1 N1 N1 N1
A) 6.2 A/m2 N1 B) 17 A/m2 C) 25 A/m2
N1 N1 D) 12 A/m2 N1 N1 N1 N1
2
,4) Current: The figure shows a 2.0-cm diameter roller that turns at 90 rpm. A 4.0-cm
N1 N1 N 1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 4) N 1
wide
N1 plastic film is being wrapped onto the roller, and this plastic carries an
N 1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1
excess electric
N1 charge having a uniform surface charge density of 5.0 nC/cm2.
N1 N 1 N1 N1 N1 N1 N1 N1 N1 N1 N1
N1 What is the current of the moving film?
N1 N1 N1 N1 N1 N1 N1
A) 11 µA N1 B) N 1 23 N1µA C) N1 190 N1nA D) N 1 30 N1nA
5) Basics of ac circuits: A 500-W device is connected to a 120-V ac power
N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 5) N 1
source.
N1 What peak current flows through this device?
N 1 N1 N1 N1 N1 N1 N1
A) 150 A B) 120 A
N1 C) 4.2 A D) 170 A E) 5.9 A N1 N1 N1 N1 N1 N1 N1 N1
6) Power: The voltage and power ratings of a particular light bulb, which are its
N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 6) N 1
normal
N1 operating values, are 110 V and 60 W. Assume the resistance
N 1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1
of the filament of the bulb is constant and is independent of operating
N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1
conditions. If the light bulb is operated with a current that is 50% of the
N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1
N1current rating of the bulb, what is the actual power drawn by the bulb?
N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1
A) 15 W B) 10 W
N1 C) 20 W D) 30 W E) 25 W
N1 N1 N1 N1 N1 N1 N1 N1
7) Power: The resistivity of gold is 2.44 × 10-8 Ω · m at room temperature. A
N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 7) N 1
gold wire that is 1.8 mm in diameter and 11 cm long carries a current
N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1
of 170 mA. How much power is dissipated in the wire?
N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1
A) 0.013 mW N1
B) 0.030 mW N1
C) 0.0076 mW N1
D) 0.025 mW N1
E) 0.019 mW N1
8) Drift velocity: A silver wire has a cross sectional area A = 2.0 mm2. A
N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1
8) N 1
N1total of 9.4 × 1018 electrons pass through the wire in 3.0 s. The
N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1
N1conduction electron density in silver is
N1 N1 N1 N1 N1
5.8 × 1028 electrons/m3 and e = 1.60 × 10-19 C. What is the drift velocity
N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1
of these electrons?
N1 N1 N1
A) 5.2 × 10-5 m/s N1 N1 N1
B) 7.4 × 10-5 m/s N1 N1 N1
C) 2.7 × 10-5 m/s N1 N1 N1
D) 1.1 × 10-5 m/s N1 N1 N1
E) 9.1 × 10-5 m/s N1 N1 N1
3
, 9) Current density: If a current of 2.4 A is flowing in a cylindrical wire of
N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 9) N 1
diameter 2.0 mm, what is the average current density in this wire?
N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1
A) 21 × 10-6 A/m2 N1 N1 N1
B) 1.9 × 105 A/m2 N1 N1 N1
C) 3.6 × 105 A/m2 N1 N1 N1
D) 7.6 × 105 A/m2 N1 N1 N1
E) 5.2 × 10-6 A/m2 N1 N1 N1
10) Power: A certain electric furnace consumes 24 kW when it is connected to
N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1
10) N 1
a 240-V line. What is the resistance of the furnace?
N1 N1 N1 N1 N1 N1 N1 N1 N1 N1
A) 1.0 kΩ B) 100 ΩN1 C) 2.4 Ω D) 0.42 Ω E) 10 Ω N1 N1 N1 N1 N1 N1 N1 N1
11) Current density: A certain fuse "blows" if the current in it exceeds 1.0 A, at
N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1
11) N 1
N1which instant N1
the fuse melts with a current density of620 A/cm2. What is the diameter of
N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1
N1the wire in the fuse?
N1 N1 N1 N1
A) 0.45 mm B) 0.91 mm
N1 C) 0.68 mm D) 0.63 mm N1 N1 N1 N1 N1 N1
12) N 1
12) Power: A 1500-W heater is connected to a 120-V line.
N1 N1 How much heat energy
N1 N1 N1 N1 N1 N1 N1 N 1 N1 N1 N1
does it
N1 produce in 2.0 hours?
N1 N 1 N1 N1 N1
A) 11 MJ B) 1.5 kJ
N1 C) 0.18 MJ D) 18 MJ E) 3.0 kJ N1 N1 N1 N1 N1 N1 N1 N1
13) N 1
13) Ohm's law: Two cables of the same length are made of the same
N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1
N1material, except that one cable has twice the diameter of the other
N1 N1 N1 N 1 N1 N1 N1 N 1 N1 N 1 N1
cable. When the same potential difference is maintained across both cables,
N 1 N 1 N 1 N1 N1 N1 N1 N1 N1 N1 N1
which of the following statements are true? (There may be more than one
N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1
correct choice.)
N1 N1
A) The current in the thin cable is twice as great as the current in the thick
N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1
cable.
N1
B) Both cables carry the same current density.
N1 N1 N1 N1 N1 N1
C) The current in the thin cable is four times as great as the current in the
N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1
thick cable.
N1 N1
D) The electrons have the same drift velocity in both cables.
N1 N1 N1 N1 N1 N1 N1 N1 N1 14) N 1
E) The same current flows through both cables.
N1 N1 N1 N1 N1 N1
14) Internal battery resistance: The emf and the internal resistance of a battery
N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1
are shown in the figure. If a current of 7.8 A is established through the battery
N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1 N1
from b to a, what is the
N1 N1 N1 terminal voltage Vab of the battery?
N1 N1 N1 N1 N 1 N1 N1 N1 N1 N1
4