Question 1

Two electrons are separated by a distance of 1.6 nm. Each experiences an electrostatic force of approximately

Accepted Answer

A)  9.0 * 109 N 
B)  1.1 * 10-32 N 
C)  9.0 * 1020 N 
D)  1.0 * 10-22 N 
E)  9.0 *10-11 N 
A)  9.0 * 109 N 
B)  1.1 * 10-32 N 
C)  9.0 * 1020 N 
D)  1.0 * 10-22 N 
E)  9.0 *10-11 N

Question 2

A particular nucleus of the element erbium contains 68 protons and 90 neutrons. What is the total number of electrons in the neutral erbium atom?

Accepted Answer

A)  90 
B)  158 
C)  22 
D)  68 
E)  None of the above 
A)  90 
B)  158 
C)  22 
D)  68 
E)  None of the above

Question 3

An electric dipole of moment   is placed in a uniform external electric field. The dipole moment vector   is in the positive x direction. The external electric field vector   is also in the positive x direction. When the dipole is aligned as shown, the net torque experienced by the dipole is

Accepted Answer

A)  in the positive x direction. 
B)  in the positive y direction. 
C)  in the negative z direction. 
D)  zero. 
E)  described by none of these. 
A)  in the positive x direction. 
B)  in the positive y direction. 
C)  in the negative z direction. 
D)  zero. 
E)  described by none of these.

Question 4

Three charges +q, +Q, and -Q are placed at the corners of an equilateral triangle as shown. The net force on charge +q due to the other two charges is

Accepted Answer

A)  vertically up. 
B)  vertically down. 
C)  zero. 
D)  horizontal to the left. 
E)  horizontal to the right. 
A)  vertically up. 
B)  vertically down. 
C)  zero. 
D)  horizontal to the left. 
E)  horizontal to the right.

Question 5

Charges q1 and q2 exert repulsive forces of 15 N on each other. What is the repulsive force when their separation is increased so that their final separation is 160% of their initial separation?

Accepted Answer

A)  1.3 N 
B)  5.9 N 
C)  9.8 N 
D)  8.7 N 
E)  6.4 N 
A)  1.3 N 
B)  5.9 N 
C)  9.8 N 
D)  8.7 N 
E)  6.4 N

Question 6

Two electric dipoles, p1 and p2, are arranged as shown. The first dipole is not free to rotate but the second dipole can rotate in any direction. Which way will p2 rotate? The directions represent the following: 1 - clockwise, 2 - counter-clockwise, 3 - rotate about axis of the dipole rolling up, and 4 - rotate about axis of the dipole rolling down.

Accepted Answer

A)  1 
B)  2 
C)  3 
D)  4 
E)  None of these is correct. 
A)  1 
B)  2 
C)  3 
D)  4 
E)  None of these is correct.

Question 7

An electric dipole   of magnitude 25 p C · m makes an angle of 65º with a uniform electric field   of magnitude 3.0 *10-6 N/C. What is the magnitude of the torque on the dipole?

Accepted Answer

A)  3.2* 10-16 N · m 
B)  6.2 * 10-16 N · m 
C)  1.4 *10-15 N · m 
D)  6.8 *10-16 N · m 
E)  7.5 * 10-16 N · m 
A)  3.2* 10-16 N · m 
B)  6.2 * 10-16 N · m 
C)  1.4 *10-15 N · m 
D)  6.8 *10-16 N · m 
E)  7.5 * 10-16 N · m

Question 8

The point P is on the axis of a ring of charge, and all vectors shown lie in the yz plane. The negatively charged ring lies in the xz plane. The vector that correctly represents the direction of the electric field at this point is

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Question 9

A square has equal positive charges at three of its corners, as shown. The direction of the electric field at point P is

Accepted Answer

A)    
B)    
C)    
D)    
E)    
A)    
B)    
C)    
D)    
E)

Question 10

Electric charges of the opposite sign

Accepted Answer

A)  also have the same magnitude. 
B)  attract each other. 
C)  exert no forces on each other. 
D)  repel each other. 
E)  None of these is correct. 
A)  also have the same magnitude. 
B)  attract each other. 
C)  exert no forces on each other. 
D)  repel each other. 
E)  None of these is correct.

Question 11

Two charges of the same magnitude and sign are placed a certain distance apart. There is only one point in space near them where the electric field is zero. Which, if any, of the following statements about that point is true?

Accepted Answer

A)  It cannot be on the line joining the charges. 
B)  It must be on the line joining the charges and between the charges. 
C)  It must be on the line joining the charges but not between the charges. 
D)  Its position depends on the size of the charges. 
E)  None of these is correct. 
A)  It cannot be on the line joining the charges. 
B)  It must be on the line joining the charges and between the charges. 
C)  It must be on the line joining the charges but not between the charges. 
D)  Its position depends on the size of the charges. 
E)  None of these is correct.

Question 12

A positive charge that is in an electric field   experiences a force that is

Accepted Answer

A)  perpendicular to   . 
B)  zero because the speed is zero. 
C)  in the direction opposite to   . 
D)  in the same direction as   . 
E)  None of these is correct. 
A)  perpendicular to   . 
B)  zero because the speed is zero. 
C)  in the direction opposite to   . 
D)  in the same direction as   . 
E)  None of these is correct.

Question 13

An electron is released from rest in a uniform electric field. If the electric field is 3.65 kN/C, at the end of 15 ns the electron's velocity will be approximately

Accepted Answer

A)  9.6*106 m/s 
B)  3.9 * 103 m/s 
C)  3.1 *108 m/s 
D)  5.5 * 103 m/s 
E)  7.4 * 106 m/s 
A)  9.6*106 m/s 
B)  3.9 * 103 m/s 
C)  3.1 *108 m/s 
D)  5.5 * 103 m/s 
E)  7.4 * 106 m/s

Question 14

Two small spheres attract one another electrostatically. This can occur for a variety of reasons. Which of the following statements must be true?

Accepted Answer

A)  at least one sphere is charged 
B)  neither is charged 
C)  both are charged 
D)  both have the same charge 
E)  None of these is correct. 
A)  at least one sphere is charged 
B)  neither is charged 
C)  both are charged 
D)  both have the same charge 
E)  None of these is correct.

Question 15

Three charges, each of Q = 3.2 *10-19 C, are arranged at three of the corners of a 20-nm square as shown. The magnitude of the electric field at D, the fourth corner of the square, is approximately

Accepted Answer

A)  1.4 * 107 N/C 
B)  1.0 * 1011 N/C 
C)  3.6 *1010 N/C 
D)  30 N/C 
E)  1.8* 107 N/C 
A)  1.4 * 107 N/C 
B)  1.0 * 1011 N/C 
C)  3.6 *1010 N/C 
D)  30 N/C 
E)  1.8* 107 N/C

Question 16

A point charge of +35 nC is above a point charge of -35 nC on a vertical line. The distance between the charges is 4.0 mm. What are the magnitude and direction of the dipole moment   ?

Accepted Answer

A)  zero 
B)  1.4 pC · m up 
C)  1.4 pC · m down 
D)  2.8 pC · m up 
E)  2.8 pC · m down 
A)  zero 
B)  1.4 pC · m up 
C)  1.4 pC · m down 
D)  2.8 pC · m up 
E)  2.8 pC · m down

Question 17

If you bring a negatively charged insulator near two uncharged metallic spheres that are in contact and then separate the spheres, the sphere on the right will have

Accepted Answer

A)  no net charge. 
B)  a positive charge. 
C)  a negative charge. 
D)  either a positive or negative charge. 
E)  None of these is correct. 
A)  no net charge. 
B)  a positive charge. 
C)  a negative charge. 
D)  either a positive or negative charge. 
E)  None of these is correct.

Question 18

An electric field with a magnitude of 6.0 *104 N/C is directed parallel to the positive y axis. A particle with a charge q = 4.8*10-19 C is moving along the x axis with a speed v = 3.0 * 106 m/s. The force on the charge is approximately

Accepted Answer

A)  8.6*10-8 N perpendicular to the xy plane. 
B)  2.9 * 10-14 N in the y direction. 
C)  8.6 * 10-8 N in the x direction. 
D)  zero. 
E)  2.9 *10-14 N in the x direction. 
A)  8.6*10-8 N perpendicular to the xy plane. 
B)  2.9 * 10-14 N in the y direction. 
C)  8.6 * 10-8 N in the x direction. 
D)  zero. 
E)  2.9 *10-14 N in the x direction.

Question 19

Experimental evidence indicates that

Accepted Answer

A)  charge is quantized and conserved. 
B)  charge is quantized but not conserved. 
C)  charge is conserved but not quantized. 
D)  charge is neither quantized nor conserved. 
E)  None of these answers is correct. 
A)  charge is quantized and conserved. 
B)  charge is quantized but not conserved. 
C)  charge is conserved but not quantized. 
D)  charge is neither quantized nor conserved. 
E)  None of these answers is correct.

Question 20

The figure shows the field lines for two charges. What is the ratio of the top charge to the bottom charge?

Accepted Answer

A)  1:2 
B)  -1:2 
C)  2:1 
D)  -2:1 
E)  2:-1 
A)  1:2 
B)  -1:2 
C)  2:1 
D)  -2:1 
E)  2:-1

Two electrons are separated by a distance of 1.6 nm. Each experiences an electrostatic force of approximately

A particular nucleus of the element erbium contains 68 protons and 90 neutrons. What is the total number of electrons in the neutral erbium atom?

An electric dipole of moment is placed in a uniform external electric field. The dipole moment vector is in the positive x direction. The external electric field vector is also in the positive x direction. When the dipole is aligned as shown, the net torque experienced by the dipole is

Three charges +q, +Q, and -Q are placed at the corners of an equilateral triangle as shown. The net force on charge +q due to the other two charges is

Charges q₁ and q₂ exert repulsive forces of 15 N on each other. What is the repulsive force when their separation is increased so that their final separation is 160% of their initial separation?

An electric dipole of magnitude 25 p C · m makes an angle of 65º with a uniform electric field of magnitude 3.0 *10^-6 N/C. What is the magnitude of the torque on the dipole?

The point P is on the axis of a ring of charge, and all vectors shown lie in the yz plane. The negatively charged ring lies in the xz plane. The vector that correctly represents the direction of the electric field at this point is

A square has equal positive charges at three of its corners, as shown. The direction of the electric field at point P is

Electric charges of the opposite sign

Two charges of the same magnitude and sign are placed a certain distance apart. There is only one point in space near them where the electric field is zero. Which, if any, of the following statements about that point is true?

A positive charge that is in an electric field experiences a force that is

An electron is released from rest in a uniform electric field. If the electric field is 3.65 kN/C, at the end of 15 ns the electron's velocity will be approximately

Two small spheres attract one another electrostatically. This can occur for a variety of reasons. Which of the following statements must be true?

Three charges, each of Q = 3.2 *10^-19 C, are arranged at three of the corners of a 20-nm square as shown. The magnitude of the electric field at D, the fourth corner of the square, is approximately

A point charge of +35 nC is above a point charge of -35 nC on a vertical line. The distance between the charges is 4.0 mm. What are the magnitude and direction of the dipole moment ?

If you bring a negatively charged insulator near two uncharged metallic spheres that are in contact and then separate the spheres, the sphere on the right will have

An electric field with a magnitude of 6.0 10⁴ N/C is directed parallel to the positive y axis. A particle with a charge q = 4.810^-19 C is moving along the x axis with a speed v = 3.0 * 10⁶ m/s. The force on the charge is approximately

Experimental evidence indicates that

The figure shows the field lines for two charges. What is the ratio of the top charge to the bottom charge?

The Electric Field II: Continuous Charge Distributions

Electric Potential

Capacitance

Electric Current and Direct-Current Circuits

The Magnetic Field

Sources of the Magnetic Field

Magnetic Induction

Alternating-Current Circuits

Maxwells Equations and Electromagnetic Waves

Properties of Light

Optical Images

Interference and Diffraction

Wave Particle Duality and Quantum Physics

Applications of the Schrodinger Equation

Atoms

Molecules

Solids and the Theory of Conduction

Relativity

Nuclear Physics

Elementary Particles and the Beginning of the Universe

Filters

Exam 1: The Electric Field I: Discrete Charge Distributions

Two electrons are separated by a distance of 1.6 nm. Each experiences an electrostatic force of approximately

A particular nucleus of the element erbium contains 68 protons and 90 neutrons. What is the total number of electrons in the neutral erbium atom?

An electric dipole of moment is placed in a uniform external electric field. The dipole moment vector is in the positive x direction. The external electric field vector is also in the positive x direction. When the dipole is aligned as shown, the net torque experienced by the dipole is

Three charges +q, +Q, and -Q are placed at the corners of an equilateral triangle as shown. The net force on charge +q due to the other two charges is

Charges q1 and q2 exert repulsive forces of 15 N on each other. What is the repulsive force when their separation is increased so that their final separation is 160% of their initial separation?

An electric dipole of magnitude 25 p C · m makes an angle of 65º with a uniform electric field of magnitude 3.0 *10-6 N/C. What is the magnitude of the torque on the dipole?

The point P is on the axis of a ring of charge, and all vectors shown lie in the yz plane. The negatively charged ring lies in the xz plane. The vector that correctly represents the direction of the electric field at this point is

A square has equal positive charges at three of its corners, as shown. The direction of the electric field at point P is

Electric charges of the opposite sign

Two charges of the same magnitude and sign are placed a certain distance apart. There is only one point in space near them where the electric field is zero. Which, if any, of the following statements about that point is true?

A positive charge that is in an electric field experiences a force that is

An electron is released from rest in a uniform electric field. If the electric field is 3.65 kN/C, at the end of 15 ns the electron's velocity will be approximately

Two small spheres attract one another electrostatically. This can occur for a variety of reasons. Which of the following statements must be true?

Three charges, each of Q = 3.2 *10-19 C, are arranged at three of the corners of a 20-nm square as shown. The magnitude of the electric field at D, the fourth corner of the square, is approximately

A point charge of +35 nC is above a point charge of -35 nC on a vertical line. The distance between the charges is 4.0 mm. What are the magnitude and direction of the dipole moment ?

If you bring a negatively charged insulator near two uncharged metallic spheres that are in contact and then separate the spheres, the sphere on the right will have

An electric field with a magnitude of 6.0 *104 N/C is directed parallel to the positive y axis. A particle with a charge q = 4.8*10-19 C is moving along the x axis with a speed v = 3.0 * 106 m/s. The force on the charge is approximately

Experimental evidence indicates that

The figure shows the field lines for two charges. What is the ratio of the top charge to the bottom charge?

The Electric Field II: Continuous Charge Distributions

Electric Potential

Capacitance

Electric Current and Direct-Current Circuits

The Magnetic Field

Sources of the Magnetic Field

Magnetic Induction

Alternating-Current Circuits

Maxwells Equations and Electromagnetic Waves

Properties of Light

Optical Images

Interference and Diffraction

Wave Particle Duality and Quantum Physics

Applications of the Schrodinger Equation

Atoms

Molecules

Solids and the Theory of Conduction

Relativity

Nuclear Physics

Elementary Particles and the Beginning of the Universe

Filters

Charges q₁ and q₂ exert repulsive forces of 15 N on each other. What is the repulsive force when their separation is increased so that their final separation is 160% of their initial separation?

An electric dipole of magnitude 25 p C · m makes an angle of 65º with a uniform electric field of magnitude 3.0 *10^-6 N/C. What is the magnitude of the torque on the dipole?

Three charges, each of Q = 3.2 *10^-19 C, are arranged at three of the corners of a 20-nm square as shown. The magnitude of the electric field at D, the fourth corner of the square, is approximately

An electric field with a magnitude of 6.0 10⁴ N/C is directed parallel to the positive y axis. A particle with a charge q = 4.810^-19 C is moving along the x axis with a speed v = 3.0 * 10⁶ m/s. The force on the charge is approximately