Question 1

When a current flows through a metal wire,the moving charges are

Accepted Answer

A) only protons. 
B) only electrons. 
C) both protons and electrons. 
D) positive metal ions. 
E) negative metal ions. 
A) only protons. 
B) only electrons. 
C) both protons and electrons. 
D) positive metal ions. 
E) negative metal ions.

Question 2

When a 1.0-m length of metal wire is connected to a  
Battery,a current of  
Flows through it.What is the diameter of the wire? The resistivity of the metal is 2.24 × 10-8 Ω ∙ m.

Accepted Answer

A) 12 μm 
B) 6.0 μm 
C) 24 μm 
D) 2.2 μm 
A) 12 μm 
B) 6.0 μm 
C) 24 μm 
D) 2.2 μm

Question 3

Five 2.0-Ω resistors are connected as shown in the figure.What is the equivalent resistance of this combination between points a and b?

Accepted Answer

A) 1.0 Ω 
B) 10.0 Ω 
C) 2.0 Ω 
D) 6.0 Ω 
E) 0.40 Ω 
A) 1.0 Ω 
B) 10.0 Ω 
C) 2.0 Ω 
D) 6.0 Ω 
E) 0.40 Ω

Question 4

If 1.5 A flows through R2,what is the emf V of the ideal battery in the figure?

Accepted Answer

A) 150 V 
B) 75 V 
C) 60 V 
D) 30 V 
A) 150 V 
B) 75 V 
C) 60 V 
D) 30 V

Question 5

For the circuit shown in the figure,both batteries are ideal.What current flows in the solid wire connecting the upper left and lower left corners of the circuit?

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 6

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

Accepted Answer

A) It is increased by a factor of 2. 
B) It is increased by a factor of 4. 
C) It is reduced by a factor of 2. 
D) It is reduced by a factor of 4. 
E) It is reduced by a factor of 8. 
A) It is increased by a factor of 2. 
B) It is increased by a factor of 4. 
C) It is reduced by a factor of 2. 
D) It is reduced by a factor of 4. 
E) It is reduced by a factor of 8.

Question 7

If the current flowing through a circuit of constant resistance is doubled,the power dissipated by that circuit will

Accepted Answer

A) quadruple in magnitude. 
B) double in magnitude. 
C) decrease to one-half of what it was. 
D) decrease to one-fourth of what it was. 
A) quadruple in magnitude. 
B) double in magnitude. 
C) decrease to one-half of what it was. 
D) decrease to one-fourth of what it was.

Question 8

A 100-W driveway light bulb is on 10 hours per day.If the power company charges 10¢ for each kilowatt-hour of electricity used,estimate the yearly cost to operate the bulb if it is used every day for a 365-day year.

Accepted Answer

A) $3.65 
B) $7.30 
C) $37 
D) $73 
A) $3.65 
B) $7.30 
C) $37 
D) $73

Question 9

Two resistors having resistances of 5.0 Ω and 9.0 Ω are connected in parallel.A 4.0-Ω resistor is then connected in series with the parallel combination.An ideal 6.0-V battery is then connected across the series-parallel combination.What is the current through the 9.0-Ω resistor?

Accepted Answer

A) 0.35 A 
B) 0.53 A 
C) 0.83 A 
D) 0.30 A 
E) 0.67 A 
A) 0.35 A 
B) 0.53 A 
C) 0.83 A 
D) 0.30 A 
E) 0.67 A

Question 10

A 5-µF,a 7-µF,and an unknown capacitor CX are connected in parallel between points a and b as shown in the figure.What do you know about the equivalent capacitance Cab between a and b? (There could be more than one correct choice. )

Accepted Answer

A) Cab > 12 µF 
B) Cab > CX 
C) 5 µF ab ab ab X 
A) Cab > 12 µF 
B) Cab > CX 
C) 5 µF ab ab ab X

Question 11

A light bulb operating at a dc voltage of 120 V has a power rating of 60 W.How much current is flowing through this bulb?

Accepted Answer

A) 1.5 A 
B) 2.5 A 
C) 0.50 A 
D) 2.0 A 
E) 1.0 A 
A) 1.5 A 
B) 2.5 A 
C) 0.50 A 
D) 2.0 A 
E) 1.0 A

Question 12

Three identical capacitors are connected in parallel to a potential source (battery).If a charge of Q flows into this combination,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 13

The resistors in the circuit shown in the figure each have a resistance of  
What is the equivalent resistance between points a and b of this combination?

Accepted Answer

A) 700 Ω 
B) 2,800 Ω 
C) 175 Ω 
D) 1,400 Ω 
A) 700 Ω 
B) 2,800 Ω 
C) 175 Ω 
D) 1,400 Ω

Question 14

When the current through a resistor is increased by a factor of 4,the power dissipated by the resistor

Accepted Answer

A) decreases by a factor of 4. 
B) decreases by a factor of 16. 
C) increases by a factor of 16. 
D) increases by a factor of 4. 
E) increases by a factor of 2. 
A) decreases by a factor of 4. 
B) decreases by a factor of 16. 
C) increases by a factor of 16. 
D) increases by a factor of 4. 
E) increases by a factor of 2.

Question 15

For the circuit shown in the figure,C = 12 µF and R = 8.5 MΩ.Initially the switch S is open with the capacitor charged to a voltage of 80 V.The switch is then closed at time t = 0.00 s.What is the charge on the capacitor,when the current in the circuit is 3.3 µA?

Accepted Answer

A) 350 µC 
B) 340 µC 
C) 480 µC 
D) 620 µC 
E) 700 µC 
A) 350 µC 
B) 340 µC 
C) 480 µC 
D) 620 µC 
E) 700 µC

Question 16

The figure shows a graph of the power dissipated in a resistor as a function of the resistance.What quantity does the slope of this graph represent?

Accepted Answer

A) the current in the resistor 
B) the potential difference across the resistor 
C) the reciprocal of the current in the resistor 
D) the square of the current in the resistor 
E) the resistivity of the resistor 
A) the current in the resistor 
B) the potential difference across the resistor 
C) the reciprocal of the current in the resistor 
D) the square of the current in the resistor 
E) the resistivity of the resistor

Question 17

Four resistors are connected across an ideal dc source of V = 8.0 V,as shown in the figure.Assume all resistances shown are accurate to two significant figures.What is the current through the 9.0-Ω resistor?

Accepted Answer

A) 1.0 A 
B) 0.67 A 
C) 0.50 A 
D) 0.90 A 
E) 2.0 A 
A) 1.0 A 
B) 0.67 A 
C) 0.50 A 
D) 0.90 A 
E) 2.0 A

Question 18

A multiloop circuit is shown in the figure,but some quantities are not labeled.Find the emf ε if the batteries are ideal.(It is not necessary to solve the entire circuit. )

Accepted Answer

A) +3 V 
B) +19 V 
C) -3 V 
D) -10 V 
E) -19 V 
A) +3 V 
B) +19 V 
C) -3 V 
D) -10 V 
E) -19 V

Question 19

Kirchhoff's loop rule is a statement of

Accepted Answer

A) the law of conservation of momentum. 
B) the law of conservation of charge. 
C) the law of conservation of energy. 
D) the law of conservation of angular momentum. 
E) Newton's second law. 
A) the law of conservation of momentum. 
B) the law of conservation of charge. 
C) the law of conservation of energy. 
D) the law of conservation of angular momentum. 
E) Newton's second law.

Question 20

The resistance of a 100-cm wire of cross sectional area 2 ×  
 
Is 400 Ω.What is the resistivity of the material from which this wire is made?

Accepted Answer

A) 0.80 ×   Ω ∙ m 
B) 8.0 ×   Ω ∙ m 
C) 0.80 ×   Ω ∙ m 
D) 0.80 ×   Ω ∙ m 
E) 8.0 ×   Ωv 
A) 0.80 ×   Ω ∙ m 
B) 8.0 ×   Ω ∙ m 
C) 0.80 ×   Ω ∙ m 
D) 0.80 ×   Ω ∙ m 
E) 8.0 ×   Ωv

Exam 21: Electric Current and Direct-Current Circuits

When a current flows through a metal wire,the moving charges are

When a 1.0-m length of metal wire is connected to a Battery,a current of Flows through it.What is the diameter of the wire? The resistivity of the metal is 2.24 × 10-8 Ω ∙ m.

Five 2.0-Ω resistors are connected as shown in the figure.What is the equivalent resistance of this combination between points a and b?

If 1.5 A flows through R2,what is the emf V of the ideal battery in the figure?

For the circuit shown in the figure,both batteries are ideal.What current flows in the solid wire connecting the upper left and lower left corners of the circuit?

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

If the current flowing through a circuit of constant resistance is doubled,the power dissipated by that circuit will

A 100-W driveway light bulb is on 10 hours per day.If the power company charges 10¢ for each kilowatt-hour of electricity used,estimate the yearly cost to operate the bulb if it is used every day for a 365-day year.

Two resistors having resistances of 5.0 Ω and 9.0 Ω are connected in parallel.A 4.0-Ω resistor is then connected in series with the parallel combination.An ideal 6.0-V battery is then connected across the series-parallel combination.What is the current through the 9.0-Ω resistor?

A 5-µF,a 7-µF,and an unknown capacitor CX are connected in parallel between points a and b as shown in the figure.What do you know about the equivalent capacitance Cab between a and b? (There could be more than one correct choice. )

A light bulb operating at a dc voltage of 120 V has a power rating of 60 W.How much current is flowing through this bulb?

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

The resistors in the circuit shown in the figure each have a resistance of What is the equivalent resistance between points a and b of this combination?

When the current through a resistor is increased by a factor of 4,the power dissipated by the resistor

For the circuit shown in the figure,C = 12 µF and R = 8.5 MΩ.Initially the switch S is open with the capacitor charged to a voltage of 80 V.The switch is then closed at time t = 0.00 s.What is the charge on the capacitor,when the current in the circuit is 3.3 µA?

The figure shows a graph of the power dissipated in a resistor as a function of the resistance.What quantity does the slope of this graph represent?

Four resistors are connected across an ideal dc source of V = 8.0 V,as shown in the figure.Assume all resistances shown are accurate to two significant figures.What is the current through the 9.0-Ω resistor?

A multiloop circuit is shown in the figure,but some quantities are not labeled.Find the emf ε if the batteries are ideal.(It is not necessary to solve the entire circuit. )

Kirchhoff's loop rule is a statement of

The resistance of a 100-cm wire of cross sectional area 2 × Is 400 Ω.What is the resistivity of the material from which this wire is made?

Introduction to Physics

One-Dimensional Kinematics

Vectors in Physics

Two-Dimensional Kinematics

Newtons Laws of Motion

Applications of Newtons Laws

Work and Kinetic Energy

Potential Energy and Conservation of Energy

Linear Momentum and Collisions

Rotational Kinematics and Energy

Rotational Dynamics and Static Equilibrium

Gravity

Oscillations About Equilibrium

Waves and Sound

Fluids

Temperature and Heat

Phases and Phase Changes

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

Geometrical Optics

Optical Instruments

Physical Optics: Interference and Diffraction

Relativity

Quantum Physics

Atomic Physics

Nuclear Physics and Nuclear Radiation

Filters

When a 1.0-m length of metal wire is connected to a Battery,a current of Flows through it.What is the diameter of the wire? The resistivity of the metal is 2.24 × 10^-8 Ω ∙ m.

If 1.5 A flows through R₂,what is the emf V of the ideal battery in the figure?

A 5-µF,a 7-µF,and an unknown capacitor C_X are connected in parallel between points a and b as shown in the figure.What do you know about the equivalent capacitance C_ab between a and b? (There could be more than one correct choice. )