Question 1

When charging two objects by rubbing them together:

Accepted Answer

A)  Neither may be a conductor. 
B)  They must be made of different material. 
C)  They will sometimes end up with both being positively charged. 
D)  The heat produced by friction is a necessary part of this process. 
A)  Neither may be a conductor. 
B)  They must be made of different material. 
C)  They will sometimes end up with both being positively charged. 
D)  The heat produced by friction is a necessary part of this process. B

Question 2

The constant ke,which appears in Coulomb's law formula,is equivalent dimensionally to which of the following?

Accepted Answer

A)  N⋅m/C 
B)  N/C 
C)  N⋅m2/C2 
D)  N/C2 
A)  N⋅m/C 
B)  N/C 
C)  N⋅m2/C2 
D)  N/C2 C

Question 3

If body M,with a positive charge,is used to charge body N by induction,what will be the nature of the charge left on the latter?

Accepted Answer

A)  must be equal in magnitude to that on M 
B)  must be negative 
C)  must be positive 
D)  must be greater in magnitude than that on M 
A)  must be equal in magnitude to that on M 
B)  must be negative 
C)  must be positive 
D)  must be greater in magnitude than that on M B

Question 4

An electron with a charge value of 1.6 × 10−19 C is moving in the presence of an electric field of 400 N/C.What force does the electron experience?

Accepted Answer

A)  6.4 × 10−22 N 
B)  8 × 10−21 N 
C)  6.4 × 10−17 N 
D)  4 × 1017 N 
E)  1.6 × 10−17 N 
A)  6.4 × 10−22 N 
B)  8 × 10−21 N 
C)  6.4 × 10−17 N 
D)  4 × 1017 N 
E)  1.6 × 10−17 N

Question 5

The beam of electrons that hits the screen of an oscilloscope is moved up and down by:

Accepted Answer

A)  gravity. 
B)  a phosphorescent coating. 
C)  varying the electron's charge. 
D)  electrical charges on deflecting plates. 
A)  gravity. 
B)  a phosphorescent coating. 
C)  varying the electron's charge. 
D)  electrical charges on deflecting plates.

Question 6

Four charges are at the corners of a square,with B and C on opposite  
Corners.Charges A and D,on the other two corners,have equal charge,while both B and C have a charge of +1.0 C.What is the charge on A so that the force on B is zero?

Accepted Answer

A)  −1.0 C 
B)  −0.50 C 
C)  −0.35 C 
D)  −0.71 C 
A)  −1.0 C 
B)  −0.50 C 
C)  −0.35 C 
D)  −0.71 C

Question 7

Two identical iron spheres have equal positive charges and the force between them when they are 1.4 m apart is 1.4 N.What percentage of the electrons has been removed from each sphere if each sphere has 1 mole (6 × 1023)of iron atoms? (ke = 8.99 × 109 N⋅m2/C2,the atomic number of iron is 26,and the electron charge is −1.6 × 10−19 C)
​

Accepted Answer

A)  0.001% 
B)  0.000 002% 
C)  1 × 10−8 % 
D)  7 × 10−10 % 
E)  ​7 × 10−12 % 
A)  0.001% 
B)  0.000 002% 
C)  1 × 10−8 % 
D)  7 × 10−10 % 
E)  ​7 × 10−12 %

Question 8

In the Millikan oil-drop experiment it was found that oil droplets:

Accepted Answer

A)  could only have positive net charge. 
B)  could only have negative net charge. 
C)  could only have negative or zero net charge. 
D)  could have positive,negative,or zero net charge. 
A)  could only have positive net charge. 
B)  could only have negative net charge. 
C)  could only have negative or zero net charge. 
D)  could have positive,negative,or zero net charge.

Question 9

How can a charged object attract an uncharged object made of non-conducting material?

Accepted Answer

A)  The uncharged object must somehow gain a like charge. 
B)  The uncharged object must somehow gain an unlike charge. 
C)  The charges in the uncharged object can become polarized. 
D)  Attraction of an insulator is not possible. 
A)  The uncharged object must somehow gain a like charge. 
B)  The uncharged object must somehow gain an unlike charge. 
C)  The charges in the uncharged object can become polarized. 
D)  Attraction of an insulator is not possible.

Question 10

A thin uncharged conducting spherical shell has a charge q carefully placed at its center through a small hole in the shell.The charge q does not touch the shell.What is the charge on the shell?

Accepted Answer

A)  q 
B)  −q 
C)  2q 
D)  0 
A)  q 
B)  −q 
C)  2q 
D)  0

Question 11

Two point charges,separated by 1.1 cm,have charge values of +2.0 and −4.0 µC,respectively.Suppose we determine that 10 field lines radiate out from the +2.0-µC charge.If so,what might be inferred about the −4.0-μC charge with respect to field lines?
​

Accepted Answer

A)  5 radiate out 
B)  20 radiate out 
C)  20 radiate in 
D)  10 radiate in 
E)  10 radiate out 
A)  5 radiate out 
B)  20 radiate out 
C)  20 radiate in 
D)  10 radiate in 
E)  10 radiate out

Question 12

Electrons in a particle beam each have a kinetic energy of 4.5 × 10−17 J.What is the magnitude of the electric field that will stop these electrons in a distance of 0.6 m? (e = 1.6 × 10−19 C)

Accepted Answer

A)  4,320 N/C 
B)  16,875 N/C 
C)  4,688 N/C 
D)  593 N/C 
E)  ​3,516 N/C 
A)  4,320 N/C 
B)  16,875 N/C 
C)  4,688 N/C 
D)  593 N/C 
E)  ​3,516 N/C

Question 13

Charge A has 10 electric field lines coming out,Charge B has 20 lines coming out,and Charge C has 30 lines coming in.Which pair of these charges will have the largest force between them if placed one cm apart?

Accepted Answer

A)  A and B 
B)  B and C 
C)  C and A 
D)  More information is needed. 
A)  A and B 
B)  B and C 
C)  C and A 
D)  More information is needed.

Question 14

Of the following substances,which one contains the highest density of free electrons?

Accepted Answer

A)  hard rubber 
B)  iron 
C)  amber 
D)  glass 
A)  hard rubber 
B)  iron 
C)  amber 
D)  glass

Question 15

A charge of +2 C is at the origin.When charge Q is placed at 2 m along the positive x axis,the electric field at 2 m along the negative x axis becomes zero.What is the value of Q?

Accepted Answer

A)  −3 C 
B)  −6 C 
C)  −7 C 
D)  −8 C 
A)  −3 C 
B)  −6 C 
C)  −7 C 
D)  −8 C

Question 16

A closed surface contains the following point charges: 9 C,6 C,-3 C,-6 C.The electric flux coming out of the surface is:
​

Accepted Answer

A)  36 C/εo. 
B)  -36 C/εo. 
C)  6 C/εo. 
D)  -6 C/εo. 
E)  ​0 C/εo. 
A)  36 C/εo. 
B)  -36 C/εo. 
C)  6 C/εo. 
D)  -6 C/εo. 
E)  ​0 C/εo.

Question 17

A Van de Graaff generator has a spherical dome of radius 27 cm.Operating in dry air,where "atmospheric breakdown" is at Emax = 3.0 × 106 N/C,what is the maximum charge that can be held on the dome? (ke = 8.99 × 109 N⋅m2/C2)
​

Accepted Answer

A)  4.9 × 10−5 C 
B)  2.4 × 10−5 C 
C)  1.2 × 10−6 C 
D)  24.3 × 10−6 C 
E)  ​0.9 × 10−6 C 
A)  4.9 × 10−5 C 
B)  2.4 × 10−5 C 
C)  1.2 × 10−6 C 
D)  24.3 × 10−6 C 
E)  ​0.9 × 10−6 C

Question 18

A ping-pong ball covered with a conducting graphite coating has a mass of 5.1 × 10−3 kg and a charge of 3.3 µC.What electric field directed upward will exactly balance the weight of the ball? (g = 9.8 m/s2)
​

Accepted Answer

A)  0.7 × 102 N/C 
B)  1.5 × 104 N/C 
C)  0.6 × 10−7 N/C 
D)  1.7 × 106 N/C 
E)  6.3 × 106 N/C 
A)  0.7 × 102 N/C 
B)  1.5 × 104 N/C 
C)  0.6 × 10−7 N/C 
D)  1.7 × 106 N/C 
E)  6.3 × 106 N/C

Question 19

Q1 has 50 electric field lines radiating outward and Q2 has 150 field lines converging inward.What is the ratio Q1/Q2?
​

Accepted Answer

A)  3 
B)  −3 
C)  1/3 
D)  −1/3 
E)  ​0 
A)  3 
B)  −3 
C)  1/3 
D)  −1/3 
E)  ​0

Question 20

Two point charges each have a value of 32.1 mC and are separated by a distance of 6 cm.What is the electric field midway between the two charges? (ke = 8.99 × 109 N·m2/C2)
​

Accepted Answer

A)  25.7 × 107 N/C 
B)  12.9 × 107 N/C 
C)  6.4 × 107 N/C 
D)  zero 
E)  ​8 × 107 N/C 
A)  25.7 × 107 N/C 
B)  12.9 × 107 N/C 
C)  6.4 × 107 N/C 
D)  zero 
E)  ​8 × 107 N/C

Exam 15: Electric Forces and Electric Fields

When charging two objects by rubbing them together:

The constant ke,which appears in Coulomb's law formula,is equivalent dimensionally to which of the following?

If body M,with a positive charge,is used to charge body N by induction,what will be the nature of the charge left on the latter?

An electron with a charge value of 1.6 × 10−19 C is moving in the presence of an electric field of 400 N/C.What force does the electron experience?

The beam of electrons that hits the screen of an oscilloscope is moved up and down by:

Four charges are at the corners of a square,with B and C on opposite Corners.Charges A and D,on the other two corners,have equal charge,while both B and C have a charge of +1.0 C.What is the charge on A so that the force on B is zero?

In the Millikan oil-drop experiment it was found that oil droplets:

How can a charged object attract an uncharged object made of non-conducting material?

A thin uncharged conducting spherical shell has a charge q carefully placed at its center through a small hole in the shell.The charge q does not touch the shell.What is the charge on the shell?

Two point charges,separated by 1.1 cm,have charge values of +2.0 and −4.0 µC,respectively.Suppose we determine that 10 field lines radiate out from the +2.0-µC charge.If so,what might be inferred about the −4.0-μC charge with respect to field lines? ​

Electrons in a particle beam each have a kinetic energy of 4.5 × 10−17 J.What is the magnitude of the electric field that will stop these electrons in a distance of 0.6 m? (e = 1.6 × 10−19 C)

Charge A has 10 electric field lines coming out,Charge B has 20 lines coming out,and Charge C has 30 lines coming in.Which pair of these charges will have the largest force between them if placed one cm apart?

Of the following substances,which one contains the highest density of free electrons?

A charge of +2 C is at the origin.When charge Q is placed at 2 m along the positive x axis,the electric field at 2 m along the negative x axis becomes zero.What is the value of Q?

A closed surface contains the following point charges: 9 C,6 C,-3 C,-6 C.The electric flux coming out of the surface is: ​

A Van de Graaff generator has a spherical dome of radius 27 cm.Operating in dry air,where "atmospheric breakdown" is at Emax = 3.0 × 106 N/C,what is the maximum charge that can be held on the dome? (ke = 8.99 × 109 N⋅m2/C2) ​

A ping-pong ball covered with a conducting graphite coating has a mass of 5.1 × 10−3 kg and a charge of 3.3 µC.What electric field directed upward will exactly balance the weight of the ball? (g = 9.8 m/s2) ​

Q1 has 50 electric field lines radiating outward and Q2 has 150 field lines converging inward.What is the ratio Q1/Q2? ​

Two point charges each have a value of 32.1 mC and are separated by a distance of 6 cm.What is the electric field midway between the two charges? (ke = 8.99 × 109 N·m2/C2) ​

Introduction

Introduction: Part A

Motion in One Dimension

Motion in One Dimension: Part A

Vectors and Two-Dimensional Motion

Vectors and Two-Dimensional Motion: Part A

The Laws of Motion

The Laws of Motion: Part A

Energy

Energy: Part A

Momentum and Collisions

Momentum and Collisions: Part A

Rotational Motion and the Law of Gravity

Rotational Motion and the Law of Gravity: Part A

Rotational Equilibrium and Rotational Dynamics

Rotational Equilibrium and Rotational Dynamics: Part A

Solids and Fluids

Solids and Fluids: Part A

Thermal Physics

Thermal Physics: Part A

Energy in Thermal Processes Heat and Internal Energy

Energy in Thermal Processes Heat and Internal Energy: Part A

The Laws of Thermodynamics Work in Thermodynamic Processes

The Laws of Thermodynamics Work in Thermodynamic Processes: Part A

Vibrations and Waves

Vibrations and Waves: Part A

Sound

Sound: Part A

Electric Forces and Electric Fields: Part A

Electrical Energy and Capacitance

Electrical Energy and Capacitance: Part A

Current and Resistance Electric Current

Current and Resistance Electric Current: Part A

Direct-Current Circuits Sources of EMF

Direct-Current Circuits Sources of EMF: Part A

Magnetism Magnets

Magnetism Magnets: Part A

Induced Voltages and Inductance

Induced Voltages and Inductance: Part A

Alternating-Current Circuits and Electromagnetic Waves

Alternating-Current Circuits and Electromagnetic Waves: Part A

Reflection and Refraction of Light

Reflection and Refraction of Light: Part A

Mirrors and Lenses

Mirrors and Lenses: Part A

Wave Optics

Wave Optics: Part A

Optical Instruments

Optical Instruments: Part A

Relativity

Relativity: Part A

Quantum Physics Blackbody Radiation and Plancks Hypothesis

Quantum Physics Blackbody Radiation and Plancks Hypothesis: Part A

Atomic Physics

Atomic Physics: Part A

Nuclear Physics

Nuclear Physics: Part A

Nuclear Energy and Elementary Particles

Nuclear Energy and Elementary Particles: Part A

Particle Collisions, Mediating Photons, and Quark Structures: Exploring the Fundamentals of Physics

The constant k_e,which appears in Coulomb's law formula,is equivalent dimensionally to which of the following?

An electron with a charge value of 1.6 × 10−¹⁹ C is moving in the presence of an electric field of 400 N/C.What force does the electron experience?

Two point charges,separated by 1.1 cm,have charge values of +2.0 and −4.0 µC,respectively.Suppose we determine that 10 field lines radiate out from the +2.0-µC charge.If so,what might be inferred about the −4.0-μC charge with respect to field lines?

Electrons in a particle beam each have a kinetic energy of 4.5 × 10−¹⁷ J.What is the magnitude of the electric field that will stop these electrons in a distance of 0.6 m? (e = 1.6 × 10−¹⁹ C)

A closed surface contains the following point charges: 9 C,6 C,-3 C,-6 C.The electric flux coming out of the surface is:

A Van de Graaff generator has a spherical dome of radius 27 cm.Operating in dry air,where "atmospheric breakdown" is at E_max = 3.0 × 10⁶ N/C,what is the maximum charge that can be held on the dome? (k_e = 8.99 × 10⁹ N⋅m²/C²)

A ping-pong ball covered with a conducting graphite coating has a mass of 5.1 × 10−³ kg and a charge of 3.3 µC.What electric field directed upward will exactly balance the weight of the ball? (g = 9.8 m/s²)

Q₁ has 50 electric field lines radiating outward and Q₂ has 150 field lines converging inward.What is the ratio Q₁/Q₂?

Two point charges each have a value of 32.1 mC and are separated by a distance of 6 cm.What is the electric field midway between the two charges? (k_e = 8.99 × 10⁹ N·m²/C²)