Question 1

If the electric field is in the positive x direction and has a magnitude given by E = Cx2, where C is a constant, then the electric potential is given by V =

Accepted Answer

A)  2Cx 
B)  -2Cx 
C)  Cx3/3 
D)  -Cx3/3 
E)  -3Cx3 
A)  2Cx 
B)  -2Cx 
C)  Cx3/3 
D)  -Cx3/3 
E)  -3Cx3 D

Question 2

In the diagram, the points 1, 2, and 3 are all the same very large distance from a dipole. Rank the points according to the values of the electric potential at them, from the most negative to the most positive.

Accepted Answer

A)  1, 2, 3 
B)  3, 2, 1 
C)  2, 3, 1 
D)  1, 3, 2 
E)  1 and 2 tie, then 3 
A)  1, 2, 3 
B)  3, 2, 1 
C)  2, 3, 1 
D)  1, 3, 2 
E)  1 and 2 tie, then 3 D

Question 3

A hollow metal sphere is charged to a potential V. The potential at its center is:

Accepted Answer

A)  V 
B)  0 
C)  -V 
D)  2V 
E)   $\pi$V 
A)  V 
B)  0 
C)  -V 
D)  2V 
E)   $\pi$V A

Question 4

In separate experiments, four different particles each start from far away with the same speed and impinge directly on a gold nucleus. The masses and charges of the particles are   Rank the particles according to the distance of closest approach to the gold nucleus, from smallest to largest.

Accepted Answer

A)  1, 2, 3, 4 
B)  4, 3, 2, 1 
C)  3, then 1 and 2 tie, then 4 
D)  4, then 1 and 2 tie, then 3 
E)  1 and 2 tie, then 3, then 4 
A)  1, 2, 3, 4 
B)  4, 3, 2, 1 
C)  3, then 1 and 2 tie, then 4 
D)  4, then 1 and 2 tie, then 3 
E)  1 and 2 tie, then 3, then 4

Question 5

The Earth's electric field creates a potential that increases 100 V for every meter of altitude. If an object of charge +4.5 mC and mass 68 g falls a distance of 1.0 m from rest under the influence of the Earth's electric and gravitational fields, what is its final kinetic energy?

Accepted Answer

A)  0.22 J 
B)  0.45 J 
C)  0.67 J 
D)  1.1 J 
E)  7.2 J 
A)  0.22 J 
B)  0.45 J 
C)  0.67 J 
D)  1.1 J 
E)  7.2 J

Question 6

The potential difference between the ends of a 2-meter stick that is parallel to a uniform electric field is 400 V. The magnitude of the electric field is:

Accepted Answer

A)  0 V/m 
B)  100 V/m 
C)  200 V/m 
D)  400 V/m 
E)  800 V/m 
A)  0 V/m 
B)  100 V/m 
C)  200 V/m 
D)  400 V/m 
E)  800 V/m

Question 7

During a lightning discharge, 30 C of charge move through a potential difference of 1.0 *108 V in 2.0 * 10-2 s. The energy released by this lightning bolt is:

Accepted Answer

A)  1.5 * 1011 J 
B)  3.0 * 109 J 
C)  6.0 * 107 J 
D)  3.3 *106 J 
E)  1500 J 
A)  1.5 * 1011 J 
B)  3.0 * 109 J 
C)  6.0 * 107 J 
D)  3.3 *106 J 
E)  1500 J

Question 8

An electron is accelerated from rest through a potential difference V. Its final speed is proportional to:

Accepted Answer

A)  V 
B)  V2 
C)    
D)  1/V 
E)    
A)  V 
B)  V2 
C)    
D)  1/V 
E)

Question 9

The fact that we can define electric potential energy means that:

Accepted Answer

A)  the electric force is nonconservative 
B)  the electric force is conservative 
C)  the work done on a charged particle depends on the path it takes 
D)  there is a point where the electric potential energy is exactly zero 
E)  it takes work for the electric force to move from some point a to some other point b and back again 
A)  the electric force is nonconservative 
B)  the electric force is conservative 
C)  the work done on a charged particle depends on the path it takes 
D)  there is a point where the electric potential energy is exactly zero 
E)  it takes work for the electric force to move from some point a to some other point b and back again

Question 10

A particle with a charge of 5.5 *10-8C charge is fixed at the origin. A particle with a charge of-2.3 * 10-8C charge is moved from x = 3.5 cm on the x axis to y = 3.5 cm on the y axis. The change in the potential energy of the two-charge system is:

Accepted Answer

A)  3.2 *10-4 J 
B)  -3.2*10-4 J 
C)  9.3 * 10-3 J 
D)  -9.3* 10-3 J 
E)  0 J 
A)  3.2 *10-4 J 
B)  -3.2*10-4 J 
C)  9.3 * 10-3 J 
D)  -9.3* 10-3 J 
E)  0 J

Question 11

A particle with a charge of 5.5 *10-8C is fixed at the origin. A particle with a charge of -2.3 *10-8C is moved from x = 3.5 cm on the x axis to y = 4.3 cm on the y axis. The change in potential energy of the two-particle system is:

Accepted Answer

A)  3.1 *10-3 J 
B)  -3.1 * 10-3 J 
C)  6.0*10-5 J 
D)  -6.0* 10-5 J 
E)  0 J 
A)  3.1 *10-3 J 
B)  -3.1 * 10-3 J 
C)  6.0*10-5 J 
D)  -6.0* 10-5 J 
E)  0 J

Question 12

If 500 J of work are required to carry a 40-C charge from one point to another, the potential difference between these two points is:

Accepted Answer

A)  12.5 V 
B)  20,000 V 
C)  0.08 V 
D)  depends on the path 
E)  none of these 
A)  12.5 V 
B)  20,000 V 
C)  0.08 V 
D)  depends on the path 
E)  none of these

Question 13

Compared to the magnitude of the electric potential far from a point charge, the magnitude of the electric potential far from an electric dipole:

Accepted Answer

A)  decreases more slowly with distance 
B)  decreases more quickly with distance 
C)  increases more slowly with distance 
D)  increases more quickly with distance 
E)  varies in the same way with distance 
A)  decreases more slowly with distance 
B)  decreases more quickly with distance 
C)  increases more slowly with distance 
D)  increases more quickly with distance 
E)  varies in the same way with distance

Question 14

A 5-cm radius conducting sphere has a charge density of 2 * 10-6 C/m2 on its surface. Its electric potential, relative to the potential far away, is:

Accepted Answer

A)  1.1 * 104 V 
B)  2.2 * 104 V 
C)  2.3 F* 105 V 
D)  3.6 *105 V 
E)  7.2*106 V 
A)  1.1 * 104 V 
B)  2.2 * 104 V 
C)  2.3 F* 105 V 
D)  3.6 *105 V 
E)  7.2*106 V

Question 15

A conducting sphere with radius R is charged until the magnitude of the electric field just outside its surface is E. The electric potential of the sphere, relative to the potential for away, is:

Accepted Answer

A)  0 
B)  E/R 
C)  E/R2 
D)  ER 
E)  ER2 
A)  0 
B)  E/R 
C)  E/R2 
D)  ER 
E)  ER2

Question 16

A conducting sphere has charge Q and its electric potential is V, relative to the potential far away. If the charge is doubled to 2Q, the potential is:

Accepted Answer

A)  V 
B)  2V 
C)  4V 
D)  V/2 
E)  V/4 
A)  V 
B)  2V 
C)  4V 
D)  V/2 
E)  V/4

Question 17

The potential difference between two points is 100 V. If a particle with a charge of 2 C is transported from one of these points to the other, the magnitude of the work done is:

Accepted Answer

A)  200 J 
B)  100 J 
C)  50 J 
D)  100 V 
E)  2 J 
A)  200 J 
B)  100 J 
C)  50 J 
D)  100 V 
E)  2 J

Question 18

The electric potential at a certain point is given by V = -7.5x2 + 3x, where V is in volts and x is in meters. What is the electric field at that point?

Accepted Answer

A)  = (15x - 3) 
B)  = (-15x + 3) 
C)  = (-2.5x3 + 1.5 x2) 
D)  = (2.5x3 - 1.5 x2) 
E)  = 0 
A)  = (15x - 3) 
B)  = (-15x + 3) 
C)  = (-2.5x3 + 1.5 x2) 
D)  = (2.5x3 - 1.5 x2) 
E)  = 0

Question 19

The graph shows the electric field as a function of position in a particular region of space. If Exs = 100 N/C, what is the potential difference between x = 3 m and x = 6 m?

Accepted Answer

A)  250 V 
B)  50 V 
C)  0 V 
D)  -50 V 
E)  -250 V 
A)  250 V 
B)  50 V 
C)  0 V 
D)  -50 V 
E)  -250 V

Question 20

Two identical particles, each with charge q, are placed on the x axis, one at the origin and the other at x = 5 cm. A third particle, with charge -q, is placed on the x axis so the potential energy of the three-particle system is the same as the potential energy when they are all infinitely far apart. Its x coordinate is:

Accepted Answer

A)  13 cm 
B)  2.5 cm 
C)  7.5 cm 
D)  10 cm 
E)  -5 cm 
A)  13 cm 
B)  2.5 cm 
C)  7.5 cm 
D)  10 cm 
E)  -5 cm

Exam 24: Electric Potential

If the electric field is in the positive x direction and has a magnitude given by E = Cx2, where C is a constant, then the electric potential is given by V =

In the diagram, the points 1, 2, and 3 are all the same very large distance from a dipole. Rank the points according to the values of the electric potential at them, from the most negative to the most positive.

A hollow metal sphere is charged to a potential V. The potential at its center is:

In separate experiments, four different particles each start from far away with the same speed and impinge directly on a gold nucleus. The masses and charges of the particles are Rank the particles according to the distance of closest approach to the gold nucleus, from smallest to largest.

The Earth's electric field creates a potential that increases 100 V for every meter of altitude. If an object of charge +4.5 mC and mass 68 g falls a distance of 1.0 m from rest under the influence of the Earth's electric and gravitational fields, what is its final kinetic energy?

The potential difference between the ends of a 2-meter stick that is parallel to a uniform electric field is 400 V. The magnitude of the electric field is:

During a lightning discharge, 30 C of charge move through a potential difference of 1.0 *108 V in 2.0 * 10-2 s. The energy released by this lightning bolt is:

An electron is accelerated from rest through a potential difference V. Its final speed is proportional to:

The fact that we can define electric potential energy means that:

A particle with a charge of 5.5 *10-8C charge is fixed at the origin. A particle with a charge of-2.3 * 10-8C charge is moved from x = 3.5 cm on the x axis to y = 3.5 cm on the y axis. The change in the potential energy of the two-charge system is:

A particle with a charge of 5.5 *10-8C is fixed at the origin. A particle with a charge of -2.3 *10-8C is moved from x = 3.5 cm on the x axis to y = 4.3 cm on the y axis. The change in potential energy of the two-particle system is:

If 500 J of work are required to carry a 40-C charge from one point to another, the potential difference between these two points is:

Compared to the magnitude of the electric potential far from a point charge, the magnitude of the electric potential far from an electric dipole:

A 5-cm radius conducting sphere has a charge density of 2 * 10-6 C/m2 on its surface. Its electric potential, relative to the potential far away, is:

A conducting sphere with radius R is charged until the magnitude of the electric field just outside its surface is E. The electric potential of the sphere, relative to the potential for away, is:

A conducting sphere has charge Q and its electric potential is V, relative to the potential far away. If the charge is doubled to 2Q, the potential is:

The potential difference between two points is 100 V. If a particle with a charge of 2 C is transported from one of these points to the other, the magnitude of the work done is:

The electric potential at a certain point is given by V = -7.5x2 + 3x, where V is in volts and x is in meters. What is the electric field at that point?

The graph shows the electric field as a function of position in a particular region of space. If Exs = 100 N/C, what is the potential difference between x = 3 m and x = 6 m?

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If the electric field is in the positive x direction and has a magnitude given by E = Cx², where C is a constant, then the electric potential is given by V =

During a lightning discharge, 30 C of charge move through a potential difference of 1.0 10⁸ V in 2.0 10^-2 s. The energy released by this lightning bolt is:

A particle with a charge of 5.5 10^-8C charge is fixed at the origin. A particle with a charge of-2.3 10^-8C charge is moved from x = 3.5 cm on the x axis to y = 3.5 cm on the y axis. The change in the potential energy of the two-charge system is:

A particle with a charge of 5.5 10^-8C is fixed at the origin. A particle with a charge of -2.3 10^-8C is moved from x = 3.5 cm on the x axis to y = 4.3 cm on the y axis. The change in potential energy of the two-particle system is:

A 5-cm radius conducting sphere has a charge density of 2 * 10^-6 C/m² on its surface. Its electric potential, relative to the potential far away, is:

The electric potential at a certain point is given by V = -7.5x² + 3x, where V is in volts and x is in meters. What is the electric field at that point?

The graph shows the electric field as a function of position in a particular region of space. If E_xs = 100 N/C, what is the potential difference between x = 3 m and x = 6 m?