Question 1

When different resistors are connected in parallel across an ideal battery,we can be certain that

Accepted Answer

A) the same current flows in each one. 
B) the potential difference across each is the same. 
C) the power dissipated in each is the same. 
D) their equivalent resistance is greater than the resistance of any one of the individual resistances. 
E) their equivalent resistance is equal to the average of the individual resistances. 
A) the same current flows in each one. 
B) the potential difference across each is the same. 
C) the power dissipated in each is the same. 
D) their equivalent resistance is greater than the resistance of any one of the individual resistances. 
E) their equivalent resistance is equal to the average of the individual resistances.

Question 2

A 400-W computer (including its monitor)is turned on for 8.0 hours per day.If electricity costs 10¢ per kWh,how much does it cost to run the computer annually for a 365-day year?

Accepted Answer

A) $120 
B) $1200 
C) $15 
D) $150 
A) $120 
B) $1200 
C) $15 
D) $150

Question 3

Three identical capacitors are connected in series across a potential source (battery).If a charge of Q flows into this combination of capacitors,how much charge does each capacitor carry?

Accepted Answer

A) 3Q 
B) Q 
C) Q/3 
D) Q/9 
A) 3Q 
B) Q 
C) Q/3 
D) Q/9

Question 4

What is the voltage drop across a 5.0-Ω resistor if the current through it is 5.0 A?

Accepted Answer

A) 100 V 
B) 25 V 
C) 4.0 V 
D) 1.0 V 
A) 100 V 
B) 25 V 
C) 4.0 V 
D) 1.0 V

Question 5

As more resistors are added in parallel across a constant voltage source,the power supplied by the source

Accepted Answer

A) increases. 
B) decreases. 
C) does not change. 
D) increases for a time and then starts to decrease. 
A) increases. 
B) decreases. 
C) does not change. 
D) increases for a time and then starts to decrease.

Question 6

The length of a certain wire is doubled while its radius is kept constant.What is the new resistance of this wire?

Accepted Answer

A) It stays the same. 
B) It is 2 times as large. 
C) It is 3 times as large. 
D) It is 4 times as large. 
E) It is 1/2 as large. 
A) It stays the same. 
B) It is 2 times as large. 
C) It is 3 times as large. 
D) It is 4 times as large. 
E) It is 1/2 as large.

Question 7

Three resistors with resistances of 2.0 Ω,6.0 Ω,and 12 Ω are connected across an ideal dc voltage source V as shown in the figure.If the total current through the circuit is I = 2.0 A,what is the applied voltage V?

Accepted Answer

A) 6.0 V 
B) 3.0 V 
C) 2.0 V 
D) 2.7 V 
E) 1.5 V 
A) 6.0 V 
B) 3.0 V 
C) 2.0 V 
D) 2.7 V 
E) 1.5 V

Question 8

Determine the current in the 4.0-Ω resistor for the circuit shown in the figure.Assume that the batteries are ideal and that all numbers are accurate to two significant figures.

Accepted Answer

A) 0.28 A 
B) 1.3 A 
C) 1.6 A 
D) 2.1 A 
A) 0.28 A 
B) 1.3 A 
C) 1.6 A 
D) 2.1 A

Question 9

Three light bulbs,A,B,and C,have electrical ratings as follows:
Bulb A: 96.0 W,1.70 A
Bulb B: 80.0 V,205 W
Bulb C: 120 V,0.400 A
These three bulbs are connected in a circuit across a 150-V voltage power source,as shown in the figure.Assume that the filament resistances of the light bulbs are constant and independent of operating conditions.What is the equivalent resistance of this combination of bulbs between the terminals of the power source?

Accepted Answer

A) 61.5 Ω 
B) 15.3 Ω 
C) 74.0 Ω 
D) 86.2 Ω 
E) 364 Ω 
A) 61.5 Ω 
B) 15.3 Ω 
C) 74.0 Ω 
D) 86.2 Ω 
E) 364 Ω

Question 10

For the graph shown in the figure,what physical quantity does the slope of the graph represent for ohmic material?

Accepted Answer

A) current 
B) resistivity 
C) 1/(current) 
D) power 
E) 1/(resistivity) 
A) current 
B) resistivity 
C) 1/(current) 
D) power 
E) 1/(resistivity)

Question 11

An ideal 100-V dc battery is applied across a series combination of four resistors having resistances of 20 Ω,40 Ω,60 Ω,and 80 Ω.What is the potential difference across the 40-Ω resistor?

Accepted Answer

A) 20 V 
B) 40 V 
C) 60 V 
D) 80 V 
E) 100 V 
A) 20 V 
B) 40 V 
C) 60 V 
D) 80 V 
E) 100 V

Question 12

The figure shows a graph of the resistance of a wire as a function of its length.What physical quantities does the slope of this graph represent?

Accepted Answer

A) the cross-sectional area of the wire 
B) the resistivity of the material of which the wire is made 
C) the product of the resistivity and the cross-sectional area of the wire 
D) the resistivity of the material divided by the cross-sectional area of the wire 
E) the reciprocal of the resistivity of the material 
A) the cross-sectional area of the wire 
B) the resistivity of the material of which the wire is made 
C) the product of the resistivity and the cross-sectional area of the wire 
D) the resistivity of the material divided by the cross-sectional area of the wire 
E) the reciprocal of the resistivity of the material

Question 13

For the graph shown in the figure,what physical quantity does the slope of the graph represent for ohmic material?

Accepted Answer

A) power 
B) resistivity 
C) 1/(resistivity) 
D) resistance 
E) 1/(resistance) 
A) power 
B) resistivity 
C) 1/(resistivity) 
D) resistance 
E) 1/(resistance)

Question 14

Determine the current in the 12-Ω resistor for the circuit shown in the figure assuming that the batteries are ideal.

Accepted Answer

A) 0.25 A 
B) 0.50 A 
C) 0.75 A 
D) 1.0 A 
A) 0.25 A 
B) 0.50 A 
C) 0.75 A 
D) 1.0 A

Question 15

What is the resistance of a 0.100-kW light bulb designed to be used in a 120-V circuit dc?

Accepted Answer

A) 12.0 Ω 
B) 144 Ω 
C) 1.2 Ω 
D) 0.83 Ω 
A) 12.0 Ω 
B) 144 Ω 
C) 1.2 Ω 
D) 0.83 Ω

Question 16

The length of a certain wire is doubled and at the same time its radius is also doubled.What is the new resistance of this wire?

Accepted Answer

A) It stays the same. 
B) It is 2 times as large. 
C) It is 4 times as large. 
D) It is 1/2 as large. 
E) It is 1/4 as large. 
A) It stays the same. 
B) It is 2 times as large. 
C) It is 4 times as large. 
D) It is 1/2 as large. 
E) It is 1/4 as large.

Question 17

A metal bar is 20 cm long and has a rectangular cross-section measuring 1.0 cm × 2.0 cm.What is the voltage drop along its length when it carries a 4000-A current? The resistivity of the metal is 1.68 × 10-8 Ω ∙ m.

Accepted Answer

A) 0.67 V 
B) 0.34 V 
C) 0.067 V 
D) 0.034 V 
A) 0.67 V 
B) 0.34 V 
C) 0.067 V 
D) 0.034 V

Question 18

What is the magnitude of the potential difference between points A and C for the circuit shown in the figure? The battery is ideal,and all the numbers are accurate to two significant figures.

Accepted Answer

A) 6.0 V 
B) 4.0 V 
C) 3.0 V 
D) 2.0 V 
A) 6.0 V 
B) 4.0 V 
C) 3.0 V 
D) 2.0 V

Question 19

A 5.0-μF,a 14-μF,and a 21- μF.  Capacitor are connected in parallel.How much capacitance would a single capacitor need to have to replace the three capacitors?

Accepted Answer

A) 40 μF 
B)  21 μF 
C) 5.0 μF 
D) 14 μF 
A) 40 μF 
B)  21 μF 
C) 5.0 μF 
D) 14 μF

Question 20

In the circuit shown in the figure,R1 = R2 = 90.0 Ω,R3 = R4 = 20.0 Ω,V1 = 7.0 V,V2 = 8.0 V,and the batteries are both ideal.What current does the ammeter read?

Accepted Answer

A) 0.40 A 
B) 0.050 A 
C) 0.83 A 
D) 0.056 A 
A) 0.40 A 
B) 0.050 A 
C) 0.83 A 
D) 0.056 A

Exam 21: Electric Current and Direct-Current Circuits

When different resistors are connected in parallel across an ideal battery,we can be certain that

A 400-W computer (including its monitor)is turned on for 8.0 hours per day.If electricity costs 10¢ per kWh,how much does it cost to run the computer annually for a 365-day year?

Three identical capacitors are connected in series across a potential source (battery).If a charge of Q flows into this combination of capacitors,how much charge does each capacitor carry?

What is the voltage drop across a 5.0-Ω resistor if the current through it is 5.0 A?

As more resistors are added in parallel across a constant voltage source,the power supplied by the source

The length of a certain wire is doubled while its radius is kept constant.What is the new resistance of this wire?

Three resistors with resistances of 2.0 Ω,6.0 Ω,and 12 Ω are connected across an ideal dc voltage source V as shown in the figure.If the total current through the circuit is I = 2.0 A,what is the applied voltage V?

Determine the current in the 4.0-Ω resistor for the circuit shown in the figure.Assume that the batteries are ideal and that all numbers are accurate to two significant figures.

For the graph shown in the figure,what physical quantity does the slope of the graph represent for ohmic material?

An ideal 100-V dc battery is applied across a series combination of four resistors having resistances of 20 Ω,40 Ω,60 Ω,and 80 Ω.What is the potential difference across the 40-Ω resistor?

The figure shows a graph of the resistance of a wire as a function of its length.What physical quantities does the slope of this graph represent?

For the graph shown in the figure,what physical quantity does the slope of the graph represent for ohmic material?

Determine the current in the 12-Ω resistor for the circuit shown in the figure assuming that the batteries are ideal.

What is the resistance of a 0.100-kW light bulb designed to be used in a 120-V circuit dc?

The length of a certain wire is doubled and at the same time its radius is also doubled.What is the new resistance of this wire?

A metal bar is 20 cm long and has a rectangular cross-section measuring 1.0 cm × 2.0 cm.What is the voltage drop along its length when it carries a 4000-A current? The resistivity of the metal is 1.68 × 10-8 Ω ∙ m.

What is the magnitude of the potential difference between points A and C for the circuit shown in the figure? The battery is ideal,and all the numbers are accurate to two significant figures.

A 5.0-μF,a 14-μF,and a 21- μF. Capacitor are connected in parallel.How much capacitance would a single capacitor need to have to replace the three capacitors?

In the circuit shown in the figure,R1 = R2 = 90.0 Ω,R3 = R4 = 20.0 Ω,V1 = 7.0 V,V2 = 8.0 V,and the batteries are both ideal.What current does the ammeter read?

Introduction to Physics

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Vectors in Physics

Two-Dimensional Kinematics

Newtons Laws of Motion

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Work and Kinetic Energy

Potential Energy and Conservation of Energy

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Rotational Dynamics and Static Equilibrium

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Oscillations About Equilibrium

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The Laws of Thermodynamics

Electric Charges, Forces, and Fields

Electric Potential and Electric

Magnetism

Magnetic Flux and Faradays Law of Induction

Alternating-Current Circuits

Electromagnetic Waves

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Physical Optics: Interference and Diffraction

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A metal bar is 20 cm long and has a rectangular cross-section measuring 1.0 cm × 2.0 cm.What is the voltage drop along its length when it carries a 4000-A current? The resistivity of the metal is 1.68 × 10^-8 Ω ∙ m.

In the circuit shown in the figure,R₁ = R₂ = 90.0 Ω,R₃ = R₄ = 20.0 Ω,V₁ = 7.0 V,V₂ = 8.0 V,and the batteries are both ideal.What current does the ammeter read?