Question 1

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

The net force on the center charge is the vector sum of the forces due to the four other charges. The forces due to the charges at the corners are equal in magnitude and opposite in direction, so they cancel out. The force due to the charge at the center is zero. Therefore, the net force on the center charge is due to the charge at the remaining corner, which is to the right of the center charge. Therefore, the net force on the center charge is to the right, which is represented by arrow A.

Question 2

By what method will a positively charged rod produce a negative charge on a conducting sphere that is placed on an insulating surface?

Accepted Answer

When a positively charged rod is brought near a conducting sphere, it induces the electrons to concentrate on the side closest to the rod, leaving a net positive charge on the opposite side. This is called induction. As the conducting sphere is on an insulating surface, it cannot transfer charge through conduction or convection. Therefore, the only plausible option is induction.

Question 3

FIGURE 19-5 
-Four point charges of equal magnitude and sign are arranged on the corners of the square of side d as shown in Figure 19-5. Which of the arrows shown represents the net force acting on the charge at the upper right hand corner of the square?

Accepted Answer

The answer of FIGURE 19-5 
-Four point charges of equal...

Question 4

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

The electric field between two oppositely charged metal plates points from the positive plate to the negative plate. In Figure 19-12, the positive plate is on the left and the negative plate is on the right, so the electric field points from left to right. Arrow A points from left to right, so it represents the correct direction of the electric field.

Question 5

A charged particle traveling along the +x axis enters an electric field directed vertically upward along the +y-axis. If the charged particle experiences a force downward because of this field, what is the sign of the charge on this particle?

Accepted Answer

The direction of the force experienced by a charged particle in an electric field is given by the direction of the field, and the sign of the charge on the particle. In this case, the field is directed upward, which means that a positively charged particle would experience a force in the upward direction. However, the particle experiences a force in the downward direction, which implies that the charge on the particle is opposite to the direction of the field, i.e. negative. Therefore, option A is correct.

Question 6

FIGURE 19-11 
-Three equal point charges of varying signs are placed on three of the corners of a square of side d as shown in Figure 19-11. Which of the arrows shown represents the direction of the net electric field at the vacant corner of the square?

Accepted Answer

The electric field due to the positively charged corner and the negatively charged corner will point towards the center of the square, while the electric field due to the other positively charged corner will point away from the center of the square. The net electric field at the vacant corner will be the vector sum of these three electric fields, which will point in the direction of arrow B.

Question 7

FIGURE 19-4 
-Four point charges of equal magnitude and sign are arranged on three of the corners of the square of side d as shown in Figure 19-4. Which of the arrows shown represents the net force acting on the charge at the upper right hand corner of the square?

Accepted Answer

The answer of FIGURE 19-4 
-Four point charges of equal...

Question 8

FIGURE 19-13 -Figure 19-13 shows four Gaussian surfaces surrounding a distribution of charges. Which Gaussian surfaces have an electric flux of +q/ε_o through them?

Accepted Answer

The answer of FIGURE 19-13 
-Figure 19-13 shows four Gaussian...

Question 9

An electron traveling along the +x-axis enters an electric field that is directed vertically down, i.e., along the negative y-axis. What will be the direction of the electric force acting on the electron after entering the electric field?

Accepted Answer

The electric force on a charged particle is in the direction opposite to the electric field for a negative charge like an electron. Since the electric field is downward, the force on the electron will be upward.

Question 10

FIGURE 19-6 
-Four point charges of varying magnitude and sign are arranged on the corners of the square of side d as shown in Figure 19-6. Which of the arrows shown represents the net force acting on the point charge with a charge +Q?

Accepted Answer

The net force on the point charge with a charge +Q is the vector sum of the forces due to the other three charges. The force due to the charge -Q is to the left, the force due to the charge +2Q is to the right, and the force due to the charge -Q is to the left. The net force is therefore to the right, which is represented by arrow A.

Question 11

FIGURE 19-2 
-Four point charges of equal magnitudes 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 19-2. Which of the arrows shown represents the net force acting on the center charge?

Accepted Answer

The net force on the center charge is the vector sum of the forces due to the other three charges. The force due to the charge at the top right corner is to the left, the force due to the charge at the bottom left corner is to the right, and the force due to the charge at the center of the square is zero. Therefore, the net force on the center charge is to the left, which is represented by arrow A.

Question 12

FIGURE 19-10 
-Three equal point charges are placed at three of the corners of a square of side d as shown in Figure 19-10. Which of the arrows shown represents the direction of the net electric field at the vacant corner of the square?

Accepted Answer

The answer of FIGURE 19-10 
-Three equal point charges are...

Question 13

FIGURE 19-9 
-Three equal point charges are placed at three of the corners of a square of side d as shown in Figure 19-9. Which of the arrows shown represents the direction of the net electric field at the center of the square?

Accepted Answer

The electric fields due to the point charges along the diagonal of the square cancel each other out due to their equal magnitudes and opposite directions, leaving only the electric fields along the sides of the square. Using vector addition, we can see that the net electric field at the center of the square points in the direction of choice C.

Question 14

FIGURE 19-8 
-Three equal point charges of varying signs are placed on the corners of a square of side d as shown in Figure 19-8. Which of the arrows shown represents the direction of the net electric field at the center of the square?

Accepted Answer

The net electric field at the center of the square is zero because the electric fields due to the three charges cancel each other out.

Question 15

A conductor is placed in an electric field under electrostatic conditions. Which of the following statements is correct for this situation?

Accepted Answer

Under electrostatic conditions, the electric field inside a conductor is zero, valence electrons move to the surface, and the electric field on the surface is perpendicular to it.

Question 16

A charged rod carrying a negative charge is brought near two spheres that are in contact with each other but insulated from the ground. If the two spheres are then separated, what kind of charge will be on the spheres?

Accepted Answer

When the negatively charged rod is brought near the spheres, electrons in the spheres are repelled away from the rod, causing the sphere near the rod to become positively charged and the other sphere to become negatively charged.

Question 17

Four equal charges are located at the corners of a square of side d. If the magnitude of each charge is doubled, then what happens to the resultant force on each charge?

Accepted Answer

The force between two charges is given by Coulomb's law, which states that the force is proportional to the product of the magnitudes of the charges. If each charge is doubled, the product of the charges becomes four times larger, thus quadrupling the force.

Question 18

Figure 19-13 shows four Gaussian surfaces surrounding a distribution of charges. Which Gaussian surfaces have no electric flux through them?

Accepted Answer

The answer of Figure 19-13 shows four Gaussian surfaces surrounding...

Question 19

FIGURE 19-7 
-Three equal point charges are placed at the corners of a square of side d as shown in Figure 19-7. Which of the arrows shown represents the direction of the net electric field at the center of the square?

Accepted Answer

The net electric field at the center of the square is zero because the electric fields due to the three charges cancel each other out.

Question 20

FIGURE 19-1 
-Three equal charges are at three of the corners of a square of side d. A fourth charge of equal magnitude is at the center of the square as shown in Figure 19-1. Which of the arrows shown represents the net force acting on the charge at the center of the square?

Accepted Answer

The answer of FIGURE 19-1 
-Three equal charges are at...

Quiz 19: Electric Charges, Forces, and Fields

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?

By what method will a positively charged rod produce a negative charge on a conducting sphere that is placed on an insulating surface?

FIGURE 19-5 -Four point charges of equal magnitude and sign are arranged on the corners of the square of side d as shown in Figure 19-5. Which of the arrows shown represents the net force acting on the charge at the upper right hand corner of the square?

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?

A charged particle traveling along the +x axis enters an electric field directed vertically upward along the +y-axis. If the charged particle experiences a force downward because of this field, what is the sign of the charge on this particle?

FIGURE 19-11 -Three equal point charges of varying signs are placed on three of the corners of a square of side d as shown in Figure 19-11. Which of the arrows shown represents the direction of the net electric field at the vacant corner of the square?

FIGURE 19-4 -Four point charges of equal magnitude and sign are arranged on three of the corners of the square of side d as shown in Figure 19-4. Which of the arrows shown represents the net force acting on the charge at the upper right hand corner of the square?

FIGURE 19-13 -Figure 19-13 shows four Gaussian surfaces surrounding a distribution of charges. Which Gaussian surfaces have an electric flux of +q/εo through them?

An electron traveling along the +x-axis enters an electric field that is directed vertically down, i.e., along the negative y-axis. What will be the direction of the electric force acting on the electron after entering the electric field?

FIGURE 19-6 -Four point charges of varying magnitude and sign are arranged on the corners of the square of side d as shown in Figure 19-6. Which of the arrows shown represents the net force acting on the point charge with a charge +Q?

FIGURE 19-2 -Four point charges of equal magnitudes 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 19-2. Which of the arrows shown represents the net force acting on the center charge?

FIGURE 19-10 -Three equal point charges are placed at three of the corners of a square of side d as shown in Figure 19-10. Which of the arrows shown represents the direction of the net electric field at the vacant corner of the square?

FIGURE 19-9 -Three equal point charges are placed at three of the corners of a square of side d as shown in Figure 19-9. Which of the arrows shown represents the direction of the net electric field at the center of the square?

FIGURE 19-8 -Three equal point charges of varying signs are placed on the corners of a square of side d as shown in Figure 19-8. Which of the arrows shown represents the direction of the net electric field at the center of the square?

A conductor is placed in an electric field under electrostatic conditions. Which of the following statements is correct for this situation?

A charged rod carrying a negative charge is brought near two spheres that are in contact with each other but insulated from the ground. If the two spheres are then separated, what kind of charge will be on the spheres?

Four equal charges are located at the corners of a square of side d. If the magnitude of each charge is doubled, then what happens to the resultant force on each charge?

Figure 19-13 shows four Gaussian surfaces surrounding a distribution of charges. Which Gaussian surfaces have no electric flux through them?

FIGURE 19-7 -Three equal point charges are placed at the corners of a square of side d as shown in Figure 19-7. Which of the arrows shown represents the direction of the net electric field at the center of the square?

FIGURE 19-1 -Three equal charges are at three of the corners of a square of side d. A fourth charge of equal magnitude is at the center of the square as shown in Figure 19-1. Which of the arrows shown represents the net force acting on the charge at the center of the square?

FIGURE 19-13 -Figure 19-13 shows four Gaussian surfaces surrounding a distribution of charges. Which Gaussian surfaces have an electric flux of +q/ε_o through them?