Question 1

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.E) A) and B)
F) All of the above

Question 2

An electron with a speed of 2.0 x 106 m/s moves into a uniform electric field of 500 N/C that is parallel to the electron's motion.How long does it take to bring the electron to rest? (me = 9.11 x 10-31 kg,e = 1.6 x 10-19 C)

Accepted Answer

A)  2.3 x 10-8 s
B)  3.5 x10-8 s
C)  1.2 x 10-7 s
D)  2.3 x 10-6 sE) All of the above
F) A) and C)

Question 3

Q1 has 50 electric field lines radiating outward and Q2 has 100 field lines converging inward.What is the ratio Q1/Q2?

Accepted Answer

A)  2
B)  -2
C)  1/2
D)  -1/2E) A) and B)
F) A) and C)

Question 4

Two identical balls have the same amount of charge,but the charge on ball A is positive and the charge on ball B is negative.The balls are placed on a smooth,level,frictionless table whose top is an insulator.Which of the following is true?

Accepted Answer

A)  Since the force on A is equal but opposite to the force on B,they will not move.
B)  They will move together with constant acceleration.
C)  Since the force on both balls is negative,they will move in the negative direction.
D)  None of the above is correct.E) None of the above
F) A) and C)

Question 5

Relative distribution of charge density on the surface of a conducting solid depends on:

Accepted Answer

A)  the shape of the conductor.
B)  mass density of the conductor.
C)  type of metal of which the conductor is made.
D)  strength of the earth's gravitational field.E) All of the above
F) B) and D)

Question 6

Two identical spheres each carry a charge of -40.0 µC.The spheres are separated by a distance of 1.00 m.What is the electric force between the spheres? (ke = 8.99 x 109 N·m2/C2)

Accepted Answer

A)  28.8 N (repulsive) 
B)  14.4 N (repulsive) 
C)  7.19 N (attractive) 
D)  43.2 N (attractive) E) A) and B)
F) A) and C)

Question 7

An airplane is flying through a thundercloud at a height of 2 000 m.(This is a very dangerous thing to do because of updrafts,turbulence,and the possibility of electric discharge. ) If there is a charge concentration of +40 C at height 3 000 m within the cloud and -40 C at height 1 000 m,what is the magnitude of the electric field E at the aircraft? (ke = 8.99 x 109 N·m2/C2)

Accepted Answer

A)  90 000 N/C
B)  180 000 N/C
C)  360 000 N/C
D)  720 000 N/CE) B) and C)
F) A) and D)

Question 8

Which of the following best characterizes electrical conductors?

Accepted Answer

A)  low mass density
B)  high tensile strength
C)  electric charges move freely
D)  poor heat conductorsE) All of the above
F) None of the above

Question 9

A spherical surface surrounds a point charge it its center.If the charge is doubled and if the radius of the surface is also doubled,what happens to the electric flux FE out of the surface and the magnitude E of the electric field at the surface as a result of these doublings?

Accepted Answer

A)  FE  and E do not change.
B)  FE increases and E remains the same.
C)  FE increases and E decreases.
D)  FE increases and E increases.E) B) and D)
F) A) and C)

Question 10

Electrons in a particle beam each have a kinetic energy of 3.2 x 10-17 J.What is the magnitude of the electric field that will stop these electrons in a distance of 0.1 m? (e = 1.6 x 10-19 C)

Accepted Answer

A)  200 N/C
B)  1 000 N/C
C)  2 000 N/C
D)  4 000 N/CE) A) and B)
F) All of the above

Question 11

A metallic object holds a charge of -3.8 x 10-6 C.What total number of electrons does this represent? (e = 1.6 x 10-19 C is the magnitude of the electronic charge. )

Accepted Answer

A)  4.2 x 1014
B)  6.1 x 1013
C)  2.4 x 1013
D)  1.6 x 1014E) B) and D)
F) B) and C)

Question 12

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)  0E) A) and B)
F) C) and D)

Question 13

A proton moving at 3.0 x 104 m/s is projected at an angle of 30  °\degree°  above a horizontal plane.If an electric field of 400 N/C is acting down,how long does it take the proton to return to the horizontal plane? (Hint: Ignore gravity.mproton = 1.67 x 10-27 kg,qproton = 1.6 x 10-19 C)

Accepted Answer

A)  7.8 x 10-7 s
B)  1.7 x 10-6 s
C)  3.9 x 10-6 s
D)  7.8 x 10-6 s E) A) and D)
F) B) and C)

Question 14

Who was the first to determine the electron's charge?

Accepted Answer

A)  Franklin
B)  Coulomb
C)  Millikan
D)  FaradayE) A) and B)
F) B) and C)

Question 15

A ping-pong ball covered with a conducting graphite coating has a mass of 5.0 x 10-3 kg and a charge of 4.0 µC.What electric field directed upward will exactly balance the weight of the ball? (g = 9.8 m/s2)

Accepted Answer

A)  8.2 x 102 N/C
B)  1.2 x 104 N/C
C)  2.0 x 10-7 N/C
D)  5.1 x 106 N/CE) All of the above
F) C) and D)

Question 16

A proton initially moves left to right long the x axis at a speed of 2.00 x 103 m/s.It moves into an electric field,which points in the negative x direction,and travels a distance of 0.200 m before coming to rest.What acceleration magnitude does the proton experience?

Accepted Answer

A)  6.67 x 103 m/s2
B)  1.00 x 107 m/s2
C)  9.33 x 109 m/s2
D)  2.67 x 1011m/s2E) B) and C)
F) A) and D)

Question 17

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.E) None of the above
F) All of the above

Exam 15: Electric Forces and Electric Fields

Electrons in a particle beam each have a kinetic energy of 3.2 x 10^-17 J.What is the magnitude of the electric field that will stop these electrons in a distance of 0.1 m? (e = 1.6 x 10^-19 C)

Correct Answer
verified

A ping-pong ball covered with a conducting graphite coating has a mass of 5.0 x 10^-3 kg and a charge of 4.0 µC.What electric field directed upward will exactly balance the weight of the ball? (g = 9.8 m/s²)

Correct Answer
verified

A spherical surface surrounds a point charge it its center.If the charge is doubled and if the radius of the surface is also doubled,what happens to the electric flux F_E out of the surface and the magnitude E of the electric field at the surface as a result of these doublings?

Correct Answer
verified

A metallic object holds a charge of -3.8 x 10^-6C.What total number of electrons does this represent? (e = 1.6 x 10^-19 C is the magnitude of the electronic charge. )

Correct Answer
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Which of the following best characterizes electrical conductors?

Correct Answer
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An electron with a speed of 2.0 x 10⁶ m/s moves into a uniform electric field of 500 N/C that is parallel to the electron's motion.How long does it take to bring the electron to rest? (m_e= 9.11 x 10^-31 kg,e = 1.6 x 10^-19 C)

Correct Answer
verified

Two identical spheres each carry a charge of -40.0 µC.The spheres are separated by a distance of 1.00 m.What is the electric force between the spheres? (k_e = 8.99 x 10⁹ N·m²/C²)

Correct Answer
verified

Who was the first to determine the electron's charge?

Correct Answer
verified

A proton initially moves left to right long the x axis at a speed of 2.00 x 10³ m/s.It moves into an electric field,which points in the negative x direction,and travels a distance of 0.200 m before coming to rest.What acceleration magnitude does the proton experience?

Correct Answer
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Two identical balls have the same amount of charge,but the charge on ball A is positive and the charge on ball B is negative.The balls are placed on a smooth,level,frictionless table whose top is an insulator.Which of the following is true?

Correct Answer
verified

When charging two objects by rubbing them together:

Correct Answer
verified

Relative distribution of charge density on the surface of a conducting solid depends on:

Correct Answer
verified

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

Correct Answer
verified

Q₁ has 50 electric field lines radiating outward and Q₂ has 100 field lines converging inward.What is the ratio Q₁/Q₂?

Correct Answer
verified

Correct Answer
verified

A proton moving at 3.0 x 10⁴ m/s is projected at an angle of 30 $\degree$ above a horizontal plane.If an electric field of 400 N/C is acting down,how long does it take the proton to return to the horizontal plane? (Hint: Ignore gravity.m_proton = 1.67 x 10^-27 kg,q_proton = 1.6 x 10^-19 C)

Correct Answer
verified

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?

Correct Answer
verified

Exam 15: Electric Forces and Electric Fields

Electrons in a particle beam each have a kinetic energy of 3.2 x 10-17 J.What is the magnitude of the electric field that will stop these electrons in a distance of 0.1 m? (e = 1.6 x 10-19 C)

Correct AnswerverifiedShow Answer

A ping-pong ball covered with a conducting graphite coating has a mass of 5.0 x 10-3 kg and a charge of 4.0 µC.What electric field directed upward will exactly balance the weight of the ball? (g = 9.8 m/s2)

Correct AnswerverifiedShow Answer

A spherical surface surrounds a point charge it its center.If the charge is doubled and if the radius of the surface is also doubled,what happens to the electric flux FE out of the surface and the magnitude E of the electric field at the surface as a result of these doublings?

Correct AnswerverifiedShow Answer

A metallic object holds a charge of -3.8 x 10-6 C.What total number of electrons does this represent? (e = 1.6 x 10-19 C is the magnitude of the electronic charge. )

Correct AnswerverifiedShow Answer

Which of the following best characterizes electrical conductors?

Correct AnswerverifiedShow Answer

An electron with a speed of 2.0 x 106 m/s moves into a uniform electric field of 500 N/C that is parallel to the electron's motion.How long does it take to bring the electron to rest? (me = 9.11 x 10-31 kg,e = 1.6 x 10-19 C)

Correct AnswerverifiedShow Answer

Two identical spheres each carry a charge of -40.0 µC.The spheres are separated by a distance of 1.00 m.What is the electric force between the spheres? (ke = 8.99 x 109 N·m2/C2)

Correct AnswerverifiedShow Answer

Who was the first to determine the electron's charge?

Correct AnswerverifiedShow Answer

A proton initially moves left to right long the x axis at a speed of 2.00 x 103 m/s.It moves into an electric field,which points in the negative x direction,and travels a distance of 0.200 m before coming to rest.What acceleration magnitude does the proton experience?

Correct AnswerverifiedShow Answer

Two identical balls have the same amount of charge,but the charge on ball A is positive and the charge on ball B is negative.The balls are placed on a smooth,level,frictionless table whose top is an insulator.Which of the following is true?

Correct AnswerverifiedShow Answer

When charging two objects by rubbing them together:

Correct AnswerverifiedShow Answer

Relative distribution of charge density on the surface of a conducting solid depends on:

Correct AnswerverifiedShow Answer

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

Correct AnswerverifiedShow Answer

Q1 has 50 electric field lines radiating outward and Q2 has 100 field lines converging inward.What is the ratio Q1/Q2?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

A proton moving at 3.0 x 104 m/s is projected at an angle of 30 °\degree° above a horizontal plane.If an electric field of 400 N/C is acting down,how long does it take the proton to return to the horizontal plane? (Hint: Ignore gravity.mproton = 1.67 x 10-27 kg,qproton = 1.6 x 10-19 C)

Correct AnswerverifiedShow Answer

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?

Correct AnswerverifiedShow Answer

Electrons in a particle beam each have a kinetic energy of 3.2 x 10^-17 J.What is the magnitude of the electric field that will stop these electrons in a distance of 0.1 m? (e = 1.6 x 10^-19 C)

Correct Answer
verified

A ping-pong ball covered with a conducting graphite coating has a mass of 5.0 x 10^-3 kg and a charge of 4.0 µC.What electric field directed upward will exactly balance the weight of the ball? (g = 9.8 m/s²)

Correct Answer
verified

A spherical surface surrounds a point charge it its center.If the charge is doubled and if the radius of the surface is also doubled,what happens to the electric flux F_E out of the surface and the magnitude E of the electric field at the surface as a result of these doublings?

Correct Answer
verified

A metallic object holds a charge of -3.8 x 10^-6C.What total number of electrons does this represent? (e = 1.6 x 10^-19 C is the magnitude of the electronic charge. )

Correct Answer
verified

Correct Answer
verified

An electron with a speed of 2.0 x 10⁶ m/s moves into a uniform electric field of 500 N/C that is parallel to the electron's motion.How long does it take to bring the electron to rest? (m_e= 9.11 x 10^-31 kg,e = 1.6 x 10^-19 C)

Correct Answer
verified

Two identical spheres each carry a charge of -40.0 µC.The spheres are separated by a distance of 1.00 m.What is the electric force between the spheres? (k_e = 8.99 x 10⁹ N·m²/C²)

Correct Answer
verified

Correct Answer
verified

A proton initially moves left to right long the x axis at a speed of 2.00 x 10³ m/s.It moves into an electric field,which points in the negative x direction,and travels a distance of 0.200 m before coming to rest.What acceleration magnitude does the proton experience?

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Q₁ has 50 electric field lines radiating outward and Q₂ has 100 field lines converging inward.What is the ratio Q₁/Q₂?

Correct Answer
verified

Correct Answer
verified

A proton moving at 3.0 x 10⁴ m/s is projected at an angle of 30 $\degree$ above a horizontal plane.If an electric field of 400 N/C is acting down,how long does it take the proton to return to the horizontal plane? (Hint: Ignore gravity.m_proton = 1.67 x 10^-27 kg,q_proton = 1.6 x 10^-19 C)

Correct Answer
verified

Correct Answer
verified