Question 1

A thin, circular disk of radius 30.0 cm is oriented in the yz-plane with its center at the origin. The disk carries a total charge of +3.00 μC distributed uniformly over its surface. Calculate the magnitude of the electric field due to the disk at the point x = 15.0 cm along the x-axis. (ε0 = 8.85 × 10-12 C2/N ∙ m2)

Accepted Answer

A)   9.95 × 105 N/C
B)   4.98 × 105 N/C
C)   3.31 × 105 N/C
D)   2.49 × 105 N/C
E)   1.99 × 105 N/C

Question 2

A small glass bead has been charged to 8.0 nC. What is the magnitude of the electric field 2.0 cm from the center of the bead? (k = 1/4πε0 = 8.99 × 109 N ∙ m2/C2)

Accepted Answer

A)   1.8 × 105 N/C
B)   3.6 × 103 N/C
C)   1.4 × 10-3 N/C
D)   3.6 × 10-6 N/C

Question 3

Three point charges are placed on the x-axis. A charge of +2.0 μC is placed at the origin, -2.0 μC to the right at x = 50 cm, and +4.0 μC at the 100 cm mark. What are the magnitude and direction of the electrostatic force that acts on the charge at the origin? (k = 1/4πε0 = 8.99 × 109 N ∙ m2/C2)

Accepted Answer

0.072 N, t...

Question 4

A positive point charge Q is fixed on a very large horizontal frictionless tabletop. A second positive point charge q is released from rest near the stationary charge and is free to move. Which statement best describes the motion of q after it is released?

Accepted Answer

A)   Its speed will be greatest just after it is released.
B)   Its acceleration is zero just after it is released.
C)   As it moves farther and farther from Q, its acceleration will keep increasing.
D)   As it moves farther and farther from Q, its speed will decrease.
E)   As it moves farther and farther from Q, its speed will keep increasing. E

Question 5

An electron is initially moving to the right when it enters a uniform electric field directed upwards. Which trajectory shown below will the electron follow?

Accepted Answer

A)   trajectory W
B)   trajectory X
C)   trajectory Y
D)   trajectory Z

Question 6

Two flat 4.0 cm × 4.0 cm electrodes carrying equal but opposite charges are spaced 2.0 mm apart with their midpoints opposite each other. Between the electrodes but not near their edges, the electric field strength is 2.5 × 106 N/C. What is the magnitude of the charge on each electrode? (ε0 = 8.85 × 10-12 C2/N ∙ m2)

Accepted Answer

A)   35 nC
B)   18 nC
C)   16 nC
D)   30 nC

Question 7

A +7.00 μC point charge and -9.00 μC point charge are placed along the x-axis at x = 0.000 cm and x = 40.0 cm, respectively. Where must a third charge, q, be placed along the x-axis so that it does not experience any net electric force due to the other two charges?

Accepted Answer

A)   -0.200 m
B)   2.99 m
C)   -0.187 m
D)   -2.99 m
E)   0.187 m

Question 8

Two identical small conducting spheres are separated by 0.60 m. The spheres carry different amounts of charge and each sphere experiences an attractive electric force of 10.8N. The total charge on the two spheres is -24 μC. The two spheres are now connected by a slender conducting wire, which is then removed. The electric force on each sphere is closest to

Accepted Answer

A)   zero.
B)   3.6 N, attractive.
C)   5.4 N, attractive.
D)   3.6 N, repulsive.
E)   5.4 N, repulsive.

Question 9

The point charge at the bottom of the figure is Q = +17 nC, and the curve is a circular arc. What is the magnitude of the force on the charge Q due to the other point charges shown? (k = 1/4πε0 = 8.99 × 109 N ∙ m2/C2)  9 N ∙ m2/C2)    A)  1.9 × 10-4 N B)  1.2 × 10-4 N C)  1.6 × 10-4 N D)  2.3 × 10-4 N" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)   1.9 × 10-4 N
B)   1.2 × 10-4 N
C)   1.6 × 10-4 N
D)   2.3 × 10-4 N A

Question 10

When two point charges are a distance d part, the electric force that each one feels from the other has magnitude F. In order to make this force twice as strong, the distance would have to be changed to

Accepted Answer

A)   2d.
B)    d.
C)   d/ 
D)   d/2.
E)   d/4.

Question 11

The figure shows two tiny 5.0-g spheres suspended from two very thin 1.0-m-long threads. The spheres repel each other after being charged to +91 nC and hang at rest as shown. What is the angle θ? (k = 1/4πε0 = 8.99 × 109 N ∙ m2/C2)  9 N ∙ m2/C2)    A)  4.1° B)  8.2° C)  12° D)  16°" class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)   4.1°
B)   8.2°
C)   12°
D)   16° A

Question 12

Two very large parallel sheets a distance d apart have their centers directly opposite each other. The sheets carry equal but opposite uniform surface charge densities. A point charge that is placed near the middle of the sheets a distance d/2 from each of them feels an electrical force F due to the sheets. If this charge is now moved closer to one of the sheets so that it is a distance d/4 from that sheet, what force will feel?

Accepted Answer

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

Question 13

Four equal negative point charges are located at the corners of a square, their positions in the xy-plane being (1, 1) , (-1, 1) , (-1, -1) , (1, -1) . The electric field on the x-axis at (1, 0)  points in the same direction as

Accepted Answer

A)   ĵ.
B)   î.
C)   -î
D)    .
E)   -ĵ .

Question 14

In the figure, charge q1 = 3.1 × 10-6 C is placed at the origin and charge q2 = -8.7 × 10-6 C is placed on the x-axis, at x = -0.20 m. Where along the x-axis can a third charge Q = -8.3 µC be placed such that the resultant force on this third charge is zero?

Accepted Answer

Question 15

Three equal negative point charges are placed at three of the corners of a square of side d. What is the magnitude of the net electric field at the center of the square? (k = 1/4πε0 = 8.99 × 109 N ∙ m2/C2)

Accepted Answer

Question 16

A point charge Q is located a short distance from a point charge 3Q, and no other charges are present. If the electrical force on Q is F, what is the electrical force on 3Q?

Accepted Answer

A)   F/3
B)   F/ 
C)   F
D)    F
E)   3F

Question 17

At a distance of 4.3 cm from the center of a very long uniformly charged wire, the electric field has magnitude 2000 N/C and is directed toward the wire. What is the charge on a 1.0 cm length of wire near the center? (ε0 = 8.85 × 10-12 C2/N ∙ m2)

Accepted Answer

A)   -0.048 nC
B)   -0.052 nC
C)   -0.044 nC
D)   -0.056 nC

Question 18

The figure shows three electric charges labeled Q1, Q2, Q3, and some electric field lines in the region surrounding the charges. What are the signs of the three charges? 1, Q2, Q3, and some electric field lines in the region surrounding the charges. What are the signs of the three charges?   A)  Q1 is positive, Q2 is negative, Q3 is positive. B)  Q1 is negative, Q2 is positive, Q3 is negative. C)  Q1 is positive, Q2 is positive, Q3 is negative. D)  All three charges are negative. E)  All three charges are positive." class="answers-bank-image d-inline" rel="preload" >

Accepted Answer

A)   Q1 is positive, Q2 is negative, Q3 is positive.
B)   Q1 is negative, Q2 is positive, Q3 is negative.
C)   Q1 is positive, Q2 is positive, Q3 is negative.
D)   All three charges are negative.
E)   All three charges are positive.

Question 19

Two point charges Q1 and Q2 of equal magnitudes and opposite signs are positioned as shown in the figure. Which of the arrows best represents the net electric field at point P due to these two charges?

Accepted Answer

A)   A
B)   B
C)   C
D)   D
E)   The field is equal to zero at point P.

Question 20

An initially-stationary electric dipole of dipole moment -10 C ∙ m)  î placed in an electric field   = (2.00 × 106 N/C)  î + (2.00 × 106 N/C)  ĵ. What is the magnitude of the maximum torque that the electric field exerts on the dipole? A)  2.00 × 10-3 N ∙ m B)  1.40 × 10-3 N ∙ m C)  2.80 × 10-3 N ∙ m D)  0.00 N ∙ m E)  1.00 × 10-3 N ∙ m" class="answers-bank-image d-inline" rel="preload" > = (5.00 × 10-10 C ∙ m)  î placed in an electric field -10 C ∙ m)  î placed in an electric field   = (2.00 × 106 N/C)  î + (2.00 × 106 N/C)  ĵ. What is the magnitude of the maximum torque that the electric field exerts on the dipole? A)  2.00 × 10-3 N ∙ m B)  1.40 × 10-3 N ∙ m C)  2.80 × 10-3 N ∙ m D)  0.00 N ∙ m E)  1.00 × 10-3 N ∙ m" class="answers-bank-image d-inline" rel="preload" >
= (2.00 × 106 N/C)  î + (2.00 × 106 N/C)  ĵ. What is the magnitude of the maximum torque that the electric field exerts on the dipole?

Accepted Answer

A)   2.00 × 10-3 N ∙ m
B)   1.40 × 10-3 N ∙ m
C)   2.80 × 10-3 N ∙ m
D)   0.00 N ∙ m
E)   1.00 × 10-3 N ∙ m

Exam 20: Electric Charge and Electric Field

Correct Answer
verified

A small glass bead has been charged to 8.0 nC. What is the magnitude of the electric field 2.0 cm from the center of the bead? (k = 1/4πε0 = 8.99 × 10₉ N ∙ m²/C²)

Correct Answer
verified

Correct Answer
verified
0.072 N, t...
View Answer

A positive point charge Q is fixed on a very large horizontal frictionless tabletop. A second positive point charge q is released from rest near the stationary charge and is free to move. Which statement best describes the motion of q after it is released?

Correct Answer
verified
E

An electron is initially moving to the right when it enters a uniform electric field directed upwards. Which trajectory shown below will the electron follow?

Correct Answer
verified

Correct Answer
verified

A +7.00 μC point charge and -9.00 μC point charge are placed along the x-axis at x = 0.000 cm and x = 40.0 cm, respectively. Where must a third charge, q, be placed along the x-axis so that it does not experience any net electric force due to the other two charges?

Correct Answer
verified

Correct Answer
verified

The point charge at the bottom of the figure is Q = +17 nC, and the curve is a circular arc. What is the magnitude of the force on the charge Q due to the other point charges shown? (k = 1/4πε0 = 8.99 × 10⁹ N ∙ m²/C²)

Correct Answer
verified
A

When two point charges are a distance d part, the electric force that each one feels from the other has magnitude F. In order to make this force twice as strong, the distance would have to be changed to

Correct Answer
verified

The figure shows two tiny 5.0-g spheres suspended from two very thin 1.0-m-long threads. The spheres repel each other after being charged to +91 nC and hang at rest as shown. What is the angle θ? (k = 1/4πε0 = 8.99 × 10⁹ N ∙ m²/C²)

Correct Answer
verified
A

Correct Answer
verified

Four equal negative point charges are located at the corners of a square, their positions in the xy-plane being (1, 1) , (-1, 1) , (-1, -1) , (1, -1) . The electric field on the x-axis at (1, 0) points in the same direction as

Correct Answer
verified

In the figure, charge q₁ = 3.1 × 10^-6 C is placed at the origin and charge q₂= -8.7 × 10^-6 C is placed on the x-axis, at x = -0.20 m. Where along the x-axis can a third charge Q = -8.3 µC be placed such that the resultant force on this third charge is zero?

Correct Answer
verified

Three equal negative point charges are placed at three of the corners of a square of side d. What is the magnitude of the net electric field at the center of the square? (k = 1/4πε0 = 8.99 × 10⁹ N ∙ m²/C²)

Correct Answer
verified

A point charge Q is located a short distance from a point charge 3Q, and no other charges are present. If the electrical force on Q is F, what is the electrical force on 3Q?

Correct Answer
verified

At a distance of 4.3 cm from the center of a very long uniformly charged wire, the electric field has magnitude 2000 N/C and is directed toward the wire. What is the charge on a 1.0 cm length of wire near the center? (ε0 = 8.85 × 10^-12 C²/N ∙ m²)

Correct Answer
verified

The figure shows three electric charges labeled Q₁, Q₂, Q₃, and some electric field lines in the region surrounding the charges. What are the signs of the three charges?

Correct Answer
verified

Two point charges Q1 and Q2 of equal magnitudes and opposite signs are positioned as shown in the figure. Which of the arrows best represents the net electric field at point P due to these two charges?

Correct Answer
verified

An initially-stationary electric dipole of dipole moment = (5.00 × 10^-10 C ∙ m) î placed in an electric field = (2.00 × 10⁶ N/C) î + (2.00 × 10⁶N/C) ĵ. What is the magnitude of the maximum torque that the electric field exerts on the dipole?

Correct Answer
verified

Exam 20: Electric Charge and Electric Field

Correct AnswerverifiedShow Answer

A small glass bead has been charged to 8.0 nC. What is the magnitude of the electric field 2.0 cm from the center of the bead? (k = 1/4πε0 = 8.99 × 109 N ∙ m2/C2)

Correct AnswerverifiedShow Answer

Correct Answerverified0.072 N, t...View AnswerShow Answer

A positive point charge Q is fixed on a very large horizontal frictionless tabletop. A second positive point charge q is released from rest near the stationary charge and is free to move. Which statement best describes the motion of q after it is released?

Correct AnswerverifiedE

An electron is initially moving to the right when it enters a uniform electric field directed upwards. Which trajectory shown below will the electron follow?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

A +7.00 μC point charge and -9.00 μC point charge are placed along the x-axis at x = 0.000 cm and x = 40.0 cm, respectively. Where must a third charge, q, be placed along the x-axis so that it does not experience any net electric force due to the other two charges?

Correct AnswerverifiedShow Answer

Correct AnswerverifiedShow Answer

The point charge at the bottom of the figure is Q = +17 nC, and the curve is a circular arc. What is the magnitude of the force on the charge Q due to the other point charges shown? (k = 1/4πε0 = 8.99 × 109 N ∙ m2/C2)

Correct AnswerverifiedA

When two point charges are a distance d part, the electric force that each one feels from the other has magnitude F. In order to make this force twice as strong, the distance would have to be changed to

Correct AnswerverifiedShow Answer

The figure shows two tiny 5.0-g spheres suspended from two very thin 1.0-m-long threads. The spheres repel each other after being charged to +91 nC and hang at rest as shown. What is the angle θ? (k = 1/4πε0 = 8.99 × 109 N ∙ m2/C2)

Correct AnswerverifiedA

Correct AnswerverifiedShow Answer

Four equal negative point charges are located at the corners of a square, their positions in the xy-plane being (1, 1) , (-1, 1) , (-1, -1) , (1, -1) . The electric field on the x-axis at (1, 0) points in the same direction as

Correct AnswerverifiedShow Answer

In the figure, charge q1 = 3.1 × 10-6 C is placed at the origin and charge q2 = -8.7 × 10-6 C is placed on the x-axis, at x = -0.20 m. Where along the x-axis can a third charge Q = -8.3 µC be placed such that the resultant force on this third charge is zero?

Correct AnswerverifiedShow Answer

Three equal negative point charges are placed at three of the corners of a square of side d. What is the magnitude of the net electric field at the center of the square? (k = 1/4πε0 = 8.99 × 109 N ∙ m2/C2)

Correct AnswerverifiedShow Answer

A point charge Q is located a short distance from a point charge 3Q, and no other charges are present. If the electrical force on Q is F, what is the electrical force on 3Q?

Correct AnswerverifiedShow Answer

At a distance of 4.3 cm from the center of a very long uniformly charged wire, the electric field has magnitude 2000 N/C and is directed toward the wire. What is the charge on a 1.0 cm length of wire near the center? (ε0 = 8.85 × 10-12 C2/N ∙ m2)

Correct AnswerverifiedShow Answer

The figure shows three electric charges labeled Q1, Q2, Q3, and some electric field lines in the region surrounding the charges. What are the signs of the three charges?

Correct AnswerverifiedShow Answer

Two point charges Q1 and Q2 of equal magnitudes and opposite signs are positioned as shown in the figure. Which of the arrows best represents the net electric field at point P due to these two charges?

Correct AnswerverifiedShow Answer

An initially-stationary electric dipole of dipole moment = (5.00 × 10-10 C ∙ m) î placed in an electric field = (2.00 × 106 N/C) î + (2.00 × 106 N/C) ĵ. What is the magnitude of the maximum torque that the electric field exerts on the dipole?

Correct AnswerverifiedShow Answer

Correct Answer
verified

A small glass bead has been charged to 8.0 nC. What is the magnitude of the electric field 2.0 cm from the center of the bead? (k = 1/4πε0 = 8.99 × 10₉ N ∙ m²/C²)

Correct Answer
verified

Correct Answer
verified
0.072 N, t...
View Answer

Correct Answer
verified
E

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

Correct Answer
verified

The point charge at the bottom of the figure is Q = +17 nC, and the curve is a circular arc. What is the magnitude of the force on the charge Q due to the other point charges shown? (k = 1/4πε0 = 8.99 × 10⁹ N ∙ m²/C²)

Correct Answer
verified
A

Correct Answer
verified

The figure shows two tiny 5.0-g spheres suspended from two very thin 1.0-m-long threads. The spheres repel each other after being charged to +91 nC and hang at rest as shown. What is the angle θ? (k = 1/4πε0 = 8.99 × 10⁹ N ∙ m²/C²)

Correct Answer
verified
A

Correct Answer
verified

Correct Answer
verified

In the figure, charge q₁ = 3.1 × 10^-6 C is placed at the origin and charge q₂= -8.7 × 10^-6 C is placed on the x-axis, at x = -0.20 m. Where along the x-axis can a third charge Q = -8.3 µC be placed such that the resultant force on this third charge is zero?

Correct Answer
verified

Three equal negative point charges are placed at three of the corners of a square of side d. What is the magnitude of the net electric field at the center of the square? (k = 1/4πε0 = 8.99 × 10⁹ N ∙ m²/C²)

Correct Answer
verified

Correct Answer
verified

At a distance of 4.3 cm from the center of a very long uniformly charged wire, the electric field has magnitude 2000 N/C and is directed toward the wire. What is the charge on a 1.0 cm length of wire near the center? (ε0 = 8.85 × 10^-12 C²/N ∙ m²)

Correct Answer
verified

The figure shows three electric charges labeled Q₁, Q₂, Q₃, and some electric field lines in the region surrounding the charges. What are the signs of the three charges?

Correct Answer
verified

Correct Answer
verified

An initially-stationary electric dipole of dipole moment = (5.00 × 10^-10 C ∙ m) î placed in an electric field = (2.00 × 10⁶ N/C) î + (2.00 × 10⁶N/C) ĵ. What is the magnitude of the maximum torque that the electric field exerts on the dipole?

Correct Answer
verified