Exam 19: Electric Charges, Forces, and Fields

Three point charges of magnitudes + 4.0 μC, - 5.0 μC, and - 9.0 μC are placed on the x-axis at x = 0 cm, x = 40 cm, and x = 120 cm, respectively. What is the force on the - 9.0 μC charge due to the other two charges?

Consider an equilateral triangle of side 20. cm. A charge of +2.0 μC is placed at one vertex and charges of -4.0 μC are placed at the other two vertices. Determine the magnitude and direction of the electric field at the center of the triangle.

When atom A loses an electron to atom B,

An electrically neutral atom does not have a net charge.

Gaussian surfaces A and B enclose the same positive charge +Q. The area of Gaussian surface A is three times larger than that of Gaussian surface B. The flux of electric field through Gaussian surface A is

Two large parallel metal plates are uniformly and oppositely charged and the electric field between them is 7.6 × 10⁶ N/C. (a) What is the charge density on each plate? (b) If the very large charged plates are moved 2 times farther apart, what is the electric field between the plates now?

An electron is placed in a constant electric field of 4.5 × 10⁴ N/C. (a) What is the force on the electron? (b) If the electron is released from rest, what is its speed after 3.0 ps?

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?

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?

A 5.0 μC charge is placed at the 0 cm mark of a meter stick and a -4.0 μC charge is placed at the 50 cm mark. At what point on a line joining the two charges is the electric field zero?

A 5.0-μC charge is placed at the 0 cm mark of a meter stick and a -4.0 μC charge is placed at the 50 cm mark. At what point on a line joining the two charges is the electric field zero?

A neutron carries a negative charge.

Conductor A has 11 electrons and conductor B has 32 electrons. The number of valence or conduction electrons in A and B is given as

When the magnitude of both interacting charges is increased by a factor of 2, the electrical forces between these charges is

Conductor A has 16 electrons and conductor B has 32 electrons. The ratio of the valence electrons of conductor A and conductor B is given as

Consider the x-axis with 4.0 μC at x = 1.0 meter and -2.0 μC at the origin. Where should 6.0 μC be placed so that the net force on it is zero?

Electrical and gravitational forces follow similar equations with one main difference:

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?

The force of attraction between a - 40.0 μC and + 108 μC charge is 4.00 N. What is the separation between these two charges?

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?