Question 1

A proton is placed in an electric field of intensity 700 N/C. What is the magnitude and direction of the acceleration of this proton due to this field?

Accepted Answer

A)  6.71 × 109 m/s2 opposite to the electric field 
B)  6.71 × 1010 m/s2 opposite to the electric field 
C)  6.71 × 1010 m/s2 in the direction of the electric field 
D)  67.1 × 1010 m/s2 opposite to the electric field 
E)  67.1 × 1010 m/s2 in the direction of the electric field 
A)  6.71 × 109 m/s2 opposite to the electric field 
B)  6.71 × 1010 m/s2 opposite to the electric field 
C)  6.71 × 1010 m/s2 in the direction of the electric field 
D)  67.1 × 1010 m/s2 opposite to the electric field 
E)  67.1 × 1010 m/s2 in the direction of the electric field

Question 2

Two point charges of + 20.0 μC and - 8.00 μC are separated by a distance of 20.0 cm. What is the intensity of electric field E midway between these two charges?

Accepted Answer

A)  25.2 × 106 N/C directed towards the negative charge 
B)  25.2 × 106N/C directed towards the positive charge 
C)  25.2 × 105 N/C directed towards the negative charge 
D)  25.2 × 105 N/C directed towards the positive charge 
E)  25.2 × 104 N/C directed towards the negative charge 
A)  25.2 × 106 N/C directed towards the negative charge 
B)  25.2 × 106N/C directed towards the positive charge 
C)  25.2 × 105 N/C directed towards the negative charge 
D)  25.2 × 105 N/C directed towards the positive charge 
E)  25.2 × 104 N/C directed towards the negative charge

Question 3

Three point charges are located at the following positions: Q1 = 2.00 μC at x = 1.00 m; Q2 = 3.00 μC at x = 0; Q3 = -5.00 μC at x = -1.00 m. What is the magnitude of the force on the 3.00-μC charge?

Accepted Answer

A)  5.40 × 10-2 N 
B)  0.135 N 
C)  0.158 N 
D)  8.10 × 10-2 N 
E)  0.189 N 
A)  5.40 × 10-2 N 
B)  0.135 N 
C)  0.158 N 
D)  8.10 × 10-2 N 
E)  0.189 N

Question 4

What are the magnitude and direction of the electric field at a distance of 1.50 m from a 50.0-nC charge?

Accepted Answer

A)  20 N/C away from the charge 
B)  20 N/C toward from the charge 
C)  10 N/C away from the charge 
D)  200 N/C away from the charge 
E)  200 N/C toward from the charge 
A)  20 N/C away from the charge 
B)  20 N/C toward from the charge 
C)  10 N/C away from the charge 
D)  200 N/C away from the charge 
E)  200 N/C toward from the charge

Question 5

FIGURE 19-12  
-Which of the arrows shown in Figure 19-12 represents the correct direction of the electric field between the two metal plates?

Accepted Answer

A)  A 
B)  B 
C)  C 
D)  D 
E)  none of the above 
A)  A 
B)  B 
C)  C 
D)  D 
E)  none of the above

Question 6

Two coins carry identical charges. These two coins are lying 2.50 m apart on a table. If each of these coins experiences a force of 2.00 N, how large is the charge on each coin?

Accepted Answer

A)  2.61 μC 
B)  26.1 μC 
C)  6.67 μC 
D)  5.22 μC 
E)  52.2 μC 
A)  2.61 μC 
B)  26.1 μC 
C)  6.67 μC 
D)  5.22 μC 
E)  52.2 μC

Question 7

Q1 = 6.0 nC is at (0.30 m, 0); Q2 = -1.0 nC is at (0, 0.10 m); Q3 = 5.0 nC is at (0, 0). What is the magnitude of the net force on the 5.0 nC charge?

Accepted Answer

A)  3.0 × 10-6 N 
B)  4.5 × 10-6 N 
C)  5.4 × 10-6 N 
D)  7.2 × 10-6 N 
E)  9.0 × 10-6 N 
A)  3.0 × 10-6 N 
B)  4.5 × 10-6 N 
C)  5.4 × 10-6 N 
D)  7.2 × 10-6 N 
E)  9.0 × 10-6 N

Question 8

The ratio of electrical force, Fe, to the gravitational force Fg, between two electrons is

Accepted Answer

A)  2.1 × 1042 
B)  4.2 × 1042 
C)  6.3 × 1042 
D)  8.4 × 1042 
E)  9.8 × 1042 
A)  2.1 × 1042 
B)  4.2 × 1042 
C)  6.3 × 1042 
D)  8.4 × 1042 
E)  9.8 × 1042

Question 9

The number of protons in the nucleus of an electrically neutral atom is equal to

Accepted Answer

A)  the number of neutrons in the nucleus. 
B)  the number of neutrons surrounding the nucleus. 
C)  the number of electrons surrounding the nucleus. 
D)  the number of electrons in the nucleus. 
E)  None of the other choices is correct. 
A)  the number of neutrons in the nucleus. 
B)  the number of neutrons surrounding the nucleus. 
C)  the number of electrons surrounding the nucleus. 
D)  the number of electrons in the nucleus. 
E)  None of the other choices is correct.

Question 10

Two point charges, initially 2.0 cm apart, experience a 1.0-N force. If they are moved to a new separation of 8.0 cm, what is the electric force between them?

Accepted Answer

A)  2.0 N 
B)  4.0 N 
C)  16 N 
D)  1/4 N 
E)  1/16 N 
A)  2.0 N 
B)  4.0 N 
C)  16 N 
D)  1/4 N 
E)  1/16 N

Question 11

The main difference between conductors and insulators is in terms of

Accepted Answer

A)  protons. 
B)  neutrons. 
C)  valence or conduction electrons. 
D)  atoms. 
E)  None of the other choices is correct. 
A)  protons. 
B)  neutrons. 
C)  valence or conduction electrons. 
D)  atoms. 
E)  None of the other choices is correct.

Question 12

A metal sphere of radius 2.0 cm carries a charge of 3.0 μC. What is the electric field 6.0 cm from the center of the sphere?

Accepted Answer

The answer of A metal sphere of radius 2.0 cm...

Question 13

There is a 5.0 μC charge at each of 3 corners of a square (each side 70. mm long). What is the force on +6.0 μC placed at the center of the square?

Accepted Answer

110 Newton

Question 14

A styrofoam ball of mass 0.120 g is placed in an electric field of 6000 N/C pointing downward. What charge must be placed on the ball for it to be suspended?

Accepted Answer

A)  -16.0 nC 
B)  -18.0 nC 
C)  -57.2 nC 
D)  -125 nC 
E)  -196 nC 
A)  -16.0 nC 
B)  -18.0 nC 
C)  -57.2 nC 
D)  -125 nC 
E)  -196 nC

Question 15

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 which acts on the charge at the origin?

Accepted Answer

A)  0.072 N right 
B)  0.072 N left 
C)  0.14 N right 
D)  0.14 N left 
E)  0 
A)  0.072 N right 
B)  0.072 N left 
C)  0.14 N right 
D)  0.14 N left 
E)  0

Question 16

Two point charges of + 40.0 μC and - 10.0 μC are separated by a distance of 20.0 cm. A +7.00 μC charge is placed midway between these two charges. What is the electric force acting on this charge because of the other two charges?

Accepted Answer

A)  0.453 N directed towards the negative charge 
B)  3.15 N directed towards the negative charge 
C)  3.15 N directed towards the positive charge 
D)  315 N directed towards the positive charge 
E)  315 N directed towards the negative charge 
A)  0.453 N directed towards the negative charge 
B)  3.15 N directed towards the negative charge 
C)  3.15 N directed towards the positive charge 
D)  315 N directed towards the positive charge 
E)  315 N directed towards the negative charge

Question 17

Two charges, Q1 and Q2, are separated by a certain distance R. If the magnitudes of the charges are doubled and their separation is also doubled, then what happens to the electrical force between these two charges?

Accepted Answer

A)  It is doubled. 
B)  It changes by a factor of 3. 
C)  reduced by a factor of   . 
D)  It is quadrupled. 
E)  It remains the same. 
A)  It is doubled. 
B)  It changes by a factor of 3. 
C)  reduced by a factor of   . 
D)  It is quadrupled. 
E)  It remains the same.

Question 18

If a conductor is placed in an electric field under electrostatic conditions, the electric field is excluded from the inside of the conductor.

Accepted Answer

A) True 
 B)False

Question 19

FIGURE 19-14  
-Two point charges of magnitudes + 5.00 μC, and + 7.00 μC are placed along the x-axis at x = 0 cm and x = 100 cm, respectively. Where must a third charge be placed along the x-axis so that it does not experience any net force because of the other two charges?

Accepted Answer

A)  4.58 cm 
B)  45.8 cm 
C)  50 cm 
D)  9.12 cm 
E)  91.2 cm 
A)  4.58 cm 
B)  45.8 cm 
C)  50 cm 
D)  9.12 cm 
E)  91.2 cm

Question 20

FIGURE 19-3  
-Four point charges of equal magnitude but with varying signs are arranged on three of the corners and at the center of the square of side d as shown in Figure 19-3. Which of the arrows shown represents the net force acting on the center charge?

Accepted Answer

A)  A 
B)  B 
C)  C 
D)  D 
E)  none of the above 
A)  A 
B)  B 
C)  C 
D)  D 
E)  none of the above

Exam 19: Electric Charges, Forces, and Fields

A proton is placed in an electric field of intensity 700 N/C. What is the magnitude and direction of the acceleration of this proton due to this field?

Two point charges of + 20.0 μC and - 8.00 μC are separated by a distance of 20.0 cm. What is the intensity of electric field E midway between these two charges?

Three point charges are located at the following positions: Q1 = 2.00 μC at x = 1.00 m; Q2 = 3.00 μC at x = 0; Q3 = -5.00 μC at x = -1.00 m. What is the magnitude of the force on the 3.00-μC charge?

What are the magnitude and direction of the electric field at a distance of 1.50 m from a 50.0-nC charge?

FIGURE 19-12 -Which of the arrows shown in Figure 19-12 represents the correct direction of the electric field between the two metal plates?

Two coins carry identical charges. These two coins are lying 2.50 m apart on a table. If each of these coins experiences a force of 2.00 N, how large is the charge on each coin?

Q1 = 6.0 nC is at (0.30 m, 0); Q2 = -1.0 nC is at (0, 0.10 m); Q3 = 5.0 nC is at (0, 0). What is the magnitude of the net force on the 5.0 nC charge?

The ratio of electrical force, Fe, to the gravitational force Fg, between two electrons is

The number of protons in the nucleus of an electrically neutral atom is equal to

Two point charges, initially 2.0 cm apart, experience a 1.0-N force. If they are moved to a new separation of 8.0 cm, what is the electric force between them?

The main difference between conductors and insulators is in terms of

A metal sphere of radius 2.0 cm carries a charge of 3.0 μC. What is the electric field 6.0 cm from the center of the sphere?

There is a 5.0 μC charge at each of 3 corners of a square (each side 70. mm long). What is the force on +6.0 μC placed at the center of the square?

A styrofoam ball of mass 0.120 g is placed in an electric field of 6000 N/C pointing downward. What charge must be placed on the ball for it to be suspended?

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 which acts on the charge at the origin?

Two point charges of + 40.0 μC and - 10.0 μC are separated by a distance of 20.0 cm. A +7.00 μC charge is placed midway between these two charges. What is the electric force acting on this charge because of the other two charges?

Two charges, Q1 and Q2, are separated by a certain distance R. If the magnitudes of the charges are doubled and their separation is also doubled, then what happens to the electrical force between these two charges?

If a conductor is placed in an electric field under electrostatic conditions, the electric field is excluded from the inside of the conductor.

FIGURE 19-14 -Two point charges of magnitudes + 5.00 μC, and + 7.00 μC are placed along the x-axis at x = 0 cm and x = 100 cm, respectively. Where must a third charge be placed along the x-axis so that it does not experience any net force because of the other two charges?

FIGURE 19-3 -Four point charges of equal magnitude but with varying signs are arranged on three of the corners and at the center of the square of side d as shown in Figure 19-3. Which of the arrows shown represents the net force acting on the center charge?

Introduction to Physics

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Three point charges are located at the following positions: Q₁ = 2.00 μC at x = 1.00 m; Q₂ = 3.00 μC at x = 0; Q₃ = -5.00 μC at x = -1.00 m. What is the magnitude of the force on the 3.00-μC charge?

Q₁ = 6.0 nC is at (0.30 m, 0); Q₂ = -1.0 nC is at (0, 0.10 m); Q₃ = 5.0 nC is at (0, 0). What is the magnitude of the net force on the 5.0 nC charge?

The ratio of electrical force, F_e, to the gravitational force F_g, between two electrons is

Two charges, Q₁ and Q₂, are separated by a certain distance R. If the magnitudes of the charges are doubled and their separation is also doubled, then what happens to the electrical force between these two charges?