Question 1

When the dipole moment of a dipole in a uniform electric field rotates to become more nearly aligned with the field:

Accepted Answer

A) the field does positive work and the potential energy increases 
B) the field does positive work and the potential energy decreases 
C) the field does negative work and the potential energy increases 
D) the field does negative work and the potential energy decreases 
E) the field does no work 
A) the field does positive work and the potential energy increases 
B) the field does positive work and the potential energy decreases 
C) the field does negative work and the potential energy increases 
D) the field does negative work and the potential energy decreases 
E) the field does no work B

Question 2

The electric field due to a uniform distribution of charge on a spherical shell is zero:

Accepted Answer

A) everywhere 
B) nowhere 
C) only at the center of the shell 
D) only inside the shell 
E) only outside the shell 
A) everywhere 
B) nowhere 
C) only at the center of the shell 
D) only inside the shell 
E) only outside the shell D

Question 3

Two protons (p1 and p2)are on the x axis, as shown below.The directions of the electric field at points 1, 2, and 3 respectively, are:

Accepted Answer

A) "$\rightarrow$, $\leftarrow$, $\rightarrow$" 
B) "$\leftarrow$, $\rightarrow$, $\leftarrow$" 
C) "$\leftarrow$, $\rightarrow$, $\rightarrow$" 
D) "$\leftarrow$, $\leftarrow$, $\leftarrow$" 
E) "$\leftarrow$, $\leftarrow$, $\rightarrow$" 
A) "$\rightarrow$, $\leftarrow$, $\rightarrow$" 
B) "$\leftarrow$, $\rightarrow$, $\leftarrow$" 
C) "$\leftarrow$, $\rightarrow$, $\rightarrow$" 
D) "$\leftarrow$, $\leftarrow$, $\leftarrow$" 
E) "$\leftarrow$, $\leftarrow$, $\rightarrow$" E

Question 4

An electric dipole consists of a particle with a charge of +6 * 10-6 C at the origin and a particle with a charge of -6 * 10-6 C on the x axis at x = 3 * 10-3 m.Its dipole moment is:

Accepted Answer

A) 1.8 * 10-8 C.m, in the positive x direction 
B) 1.8 * 10-8 C.m, in the negative x direction 
C) 0 C.m, because the net charge is 0 
D) 1.8 * 10-8 C.m, in the positive y direction 
E) 1.8 * 10-8 C.m, in the negative y direction 
A) 1.8 * 10-8 C.m, in the positive x direction 
B) 1.8 * 10-8 C.m, in the negative x direction 
C) 0 C.m, because the net charge is 0 
D) 1.8 * 10-8 C.m, in the positive y direction 
E) 1.8 * 10-8 C.m, in the negative y direction

Question 5

The magnitude of the force of a 400-N/C electric field on a 0.02-C point charge is:

Accepted Answer

A) 8 N 
B) 5 * 10-5 N 
C) 8 *10-3 N 
D) 0.08 N 
E) 2 *103 N 
A) 8 N 
B) 5 * 10-5 N 
C) 8 *10-3 N 
D) 0.08 N 
E) 2 *103 N

Question 6

An electric dipole consists of a particle with a charge of +6 * 10-6 C at the origin and a particle with a charge of -6*10-6 C on the x axis at x = 3 *10-3 m.The direction of the electric field due to the dipole at points on the x axis is:

Accepted Answer

A) in the positive x direction 
B) in the negative x direction 
C) in the positive y direction 
D) in the negative y direction 
E) in the positive x direction between the charges and in the negative x direction elsewhere 
A) in the positive x direction 
B) in the negative x direction 
C) in the positive y direction 
D) in the negative y direction 
E) in the positive x direction between the charges and in the negative x direction elsewhere

Question 7

An electric dipole is oriented parallel to a uniform electric field, as shown.   It is rotated to one of the five orientations shown below.Rank the final orientations according to the change in the potential energy of the dipole-field system, most negative to most positive.

Accepted Answer

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

Question 8

An electron traveling north enters a region where the electric field is uniform and points north.The electron:

Accepted Answer

A) speeds up 
B) slows down 
C) veers east 
D) veers west 
E) continues with the same speed in the same direction 
A) speeds up 
B) slows down 
C) veers east 
D) veers west 
E) continues with the same speed in the same direction

Question 9

A 200-N/C electric field is in the positive x direction.The force on an electron in this field is:

Accepted Answer

A) 200 N in the positive x direction 
B) 200 N in the negative x direction 
C) 3.2 * 10-17 N, in the positive x direction 
D) 3.2 *10-17 N, in the negative x direction 
E) 0 N 
A) 200 N in the positive x direction 
B) 200 N in the negative x direction 
C) 3.2 * 10-17 N, in the positive x direction 
D) 3.2 *10-17 N, in the negative x direction 
E) 0 N

Question 10

An isolated point charged point particle produces an electric field with magnitude E at a point 2 m away from the charge.A point at which the field magnitude is E/4 is:

Accepted Answer

A) 0.5 m away from the charge 
B) 1 m away from the charge 
C) 2 m away from the charge 
D) 4 m away from the charge 
E) 8 m away from the charge 
A) 0.5 m away from the charge 
B) 1 m away from the charge 
C) 2 m away from the charge 
D) 4 m away from the charge 
E) 8 m away from the charge

Question 11

Positive charge +Q is uniformly distributed on the upper half of a semicircular rod and negative charge -Q is uniformly distributed on the lower half.What is the direction of the electric field at point P, the center of the semicircle?

Accepted Answer

A) " $\uparrow$ " 
B) "  $\downarrow$ " 
C) " $\leftarrow$ " 
D) " $\rightarrow$ " 
E)  " " 
A) " $\uparrow$ " 
B) "  $\downarrow$ " 
C) " $\leftarrow$ " 
D) " $\rightarrow$ " 
E)  " "

Question 12

A disk with a uniform positive surface charge density lies in the x-y plane, centered on the origin.Along the positive z axis, the direction of the electric field is:

Accepted Answer

A) in the +z direction 
B) in the -z direction 
C) in the +x direction 
D) in the +y direction 
E) there is no field along the positive z axis 
A) in the +z direction 
B) in the -z direction 
C) in the +x direction 
D) in the +y direction 
E) there is no field along the positive z axis

Question 13

A spherical shell has an inner radius of 3.7 cm and an outer radius of 4.5 cm.If charge is distributed uniformly throughout the shell with a volume density of 6.1 *10-4 C/m3 the total charge is:

Accepted Answer

A) 1.0 *10-7 C 
B) 1.3 *10-7 C 
C) 2.0 * 10-7 C 
D) 1.7 *10-6 C 
E) 5.0 * 10-6 C 
A) 1.0 *10-7 C 
B) 1.3 *10-7 C 
C) 2.0 * 10-7 C 
D) 1.7 *10-6 C 
E) 5.0 * 10-6 C

Question 14

Let k denote 1/4 $\pi$  .The magnitude of the electric field at a distance r from an isolated point charge q is:

Accepted Answer

A) kq/r 
B) kr/q 
C) kq/r3 
D) kq/r2 
E) kq2/r2 
A) kq/r 
B) kr/q 
C) kq/r3 
D) kq/r2 
E) kq2/r2

Question 15

Two point particles, with the same charge, are located at two vertices of an equilateral triangle.A third charged particle is placed so the electric field at the third vertex is zero.The third particle must:

Accepted Answer

A) be on the perpendicular bisector of the line joining the first two charges 
B) be on the line joining the first two charges 
C) be identical to the first two charges 
D) have the same magnitude as the first two charges but may have a different sign 
E) be at the center of the triangle 
A) be on the perpendicular bisector of the line joining the first two charges 
B) be on the line joining the first two charges 
C) be identical to the first two charges 
D) have the same magnitude as the first two charges but may have a different sign 
E) be at the center of the triangle

Question 16

Electric field lines:

Accepted Answer

A) are trajectories of a test charge 
B) are vectors in the direction of the electric field 
C) form closed loops 
D) cross each other in the region between two point charges 
E) are none of the above 
A) are trajectories of a test charge 
B) are vectors in the direction of the electric field 
C) form closed loops 
D) cross each other in the region between two point charges 
E) are none of the above

Question 17

An electric dipole of dipole moment 4.5 x 10-9 C·m is in a 250 N/C electric field.If the electric field points east, and the dipole moment vector points 37° west of south, what is the potential energy?

Accepted Answer

A) -6.8 x 10-8 J 
B) -9.0 x 10-7 J 
C) 0 J 
D) 6.8 x 10-8 J 
E) 9.0 x 10-7 J 
A) -6.8 x 10-8 J 
B) -9.0 x 10-7 J 
C) 0 J 
D) 6.8 x 10-8 J 
E) 9.0 x 10-7 J

Question 18

Positive charge Q is uniformly distributed on a semicircular rod.What is the direction of the electric field at point P, the center of the semicircle?

Accepted Answer

A) " $\uparrow$ " 
B) " $\downarrow$ " 
C) " $\leftarrow$ " 
D) " $\rightarrow$ " 
E)  " " 
A) " $\uparrow$ " 
B) " $\downarrow$ " 
C) " $\leftarrow$ " 
D) " $\rightarrow$ " 
E)  " "

Question 19

An electric field is most directly related to:

Accepted Answer

A) the momentum of a test charge 
B) the kinetic energy of a test charge 
C) the potential energy of a test charge 
D) the force acting on a test charge 
E) the charge carried by a test charge 
A) the momentum of a test charge 
B) the kinetic energy of a test charge 
C) the potential energy of a test charge 
D) the force acting on a test charge 
E) the charge carried by a test charge

Question 20

The torque exerted by an electric field on a dipole is:

Accepted Answer

A) parallel to the field and perpendicular to the dipole moment 
B) parallel to both the field and dipole moment 
C) perpendicular to both the field and dipole moment 
D) parallel to the dipole moment and perpendicular to the field 
E) not related to the directions of the field and dipole moment 
A) parallel to the field and perpendicular to the dipole moment 
B) parallel to both the field and dipole moment 
C) perpendicular to both the field and dipole moment 
D) parallel to the dipole moment and perpendicular to the field 
E) not related to the directions of the field and dipole moment

Exam 22: Electric Fields

When the dipole moment of a dipole in a uniform electric field rotates to become more nearly aligned with the field:

The electric field due to a uniform distribution of charge on a spherical shell is zero:

Two protons (p1 and p2)are on the x axis, as shown below.The directions of the electric field at points 1, 2, and 3 respectively, are:

An electric dipole consists of a particle with a charge of +6 * 10-6 C at the origin and a particle with a charge of -6 * 10-6 C on the x axis at x = 3 * 10-3 m.Its dipole moment is:

The magnitude of the force of a 400-N/C electric field on a 0.02-C point charge is:

An electric dipole consists of a particle with a charge of +6 * 10-6 C at the origin and a particle with a charge of -6*10-6 C on the x axis at x = 3 *10-3 m.The direction of the electric field due to the dipole at points on the x axis is:

An electric dipole is oriented parallel to a uniform electric field, as shown. It is rotated to one of the five orientations shown below.Rank the final orientations according to the change in the potential energy of the dipole-field system, most negative to most positive.

An electron traveling north enters a region where the electric field is uniform and points north.The electron:

A 200-N/C electric field is in the positive x direction.The force on an electron in this field is:

An isolated point charged point particle produces an electric field with magnitude E at a point 2 m away from the charge.A point at which the field magnitude is E/4 is:

Positive charge +Q is uniformly distributed on the upper half of a semicircular rod and negative charge -Q is uniformly distributed on the lower half.What is the direction of the electric field at point P, the center of the semicircle?

A disk with a uniform positive surface charge density lies in the x-y plane, centered on the origin.Along the positive z axis, the direction of the electric field is:

A spherical shell has an inner radius of 3.7 cm and an outer radius of 4.5 cm.If charge is distributed uniformly throughout the shell with a volume density of 6.1 *10-4 C/m3 the total charge is:

Let k denote 1/4 π\piπ .The magnitude of the electric field at a distance r from an isolated point charge q is:

Two point particles, with the same charge, are located at two vertices of an equilateral triangle.A third charged particle is placed so the electric field at the third vertex is zero.The third particle must:

Electric field lines:

An electric dipole of dipole moment 4.5 x 10-9 C·m is in a 250 N/C electric field.If the electric field points east, and the dipole moment vector points 37° west of south, what is the potential energy?

Positive charge Q is uniformly distributed on a semicircular rod.What is the direction of the electric field at point P, the center of the semicircle?

An electric field is most directly related to:

The torque exerted by an electric field on a dipole is:

Measurement

Motion Along a Straight Line

Vectors

Motion in Two and Three Dimensions

Force and Motion

Force and Motion

Kinetic Energy and Work

Potential Energy and Conservation of Energy

Center of Mass and Linear Momentum

Rotation

Rolling, Torque, and Angular Momentum

Equilibrium and Elasticity

Gravitation

Fluids

Oscillations

Waves

Waves

Temperature, Heat, and the First Law of Thermodynamics

The Kinetic Theory of Gases

Entropy and the Second Law of Thermodynamics

Coulombs Law

Gauss Law

Electric Potential

Capacitance

Current and Resistance

Circuits

Magnetic Fields

Magnetic Fields Due to Currents

Induction and Inductance

Electromagnetic Oscillations and Alternating Current

Maxwells Equations; Magnetism of Matter

Electromagnetic Waves

Images

Interference 1

Diffraction

Relativity

Photons and Matter Waves

More About Matter Waves

All About Atoms

Conduction of Electricity in Solids

Energy From the Nucleus

Quarks, Leptons, and the Big Bang

Filters

Two protons (p₁ and p₂)are on the x axis, as shown below.The directions of the electric field at points 1, 2, and 3 respectively, are:

An electric dipole consists of a particle with a charge of +6 * 10^-6 C at the origin and a particle with a charge of -6 * 10^-6 C on the x axis at x = 3 * 10^-3 m.Its dipole moment is:

An electric dipole consists of a particle with a charge of +6 * 10^-6 C at the origin and a particle with a charge of -610^-6 C on the x axis at x = 3 10^-3 m.The direction of the electric field due to the dipole at points on the x axis is:

A spherical shell has an inner radius of 3.7 cm and an outer radius of 4.5 cm.If charge is distributed uniformly throughout the shell with a volume density of 6.1 *10^-4 C/m³ the total charge is:

Let k denote 1/4 $\pi$ $Let k denote 1/4 \pi .The magnitude of the electric field at a distance r from an isolated point charge q is:$ .The magnitude of the electric field at a distance r from an isolated point charge q is:

An electric dipole of dipole moment 4.5 x 10^-9 C·m is in a 250 N/C electric field.If the electric field points east, and the dipole moment vector points 37° west of south, what is the potential energy?