Question 1

Which of the following statements best describes the conservation of electric charge?

Accepted Answer

The total electric charge of the universe is a constant; charge is conserved in all processes.

Question 2

A glass rod is rubbed with silk, and the rod becomes positively charged. What happens at the atomic level?

Accepted Answer

Electrons are transferred from the rod to the silk.

Question 3

Which of the following materials is most likely to allow electrons to move freely throughout its structure?

Accepted Answer

Copper

Question 4

What is the magnitude of the force between two point charges, $$q_1 = 2.0$$ 	imes $$10^{-6}$$\ \mathrm{C}$$ and q_2$ = -3.0 	imes 10$$^{-6}$$\ \mathrm{C}$$, separated by $$0.05\ \mathrm{m} in $$air? (Use $$k = 8.99 	imes 10^9$\ \mathrm{N\cdot m^2$/C^2$$}$)

Accepted Answer

$$F = 2.16\ \mathrm{N}$$

Question 5

Which equation correctly expresses Coulomb’s Law for the force between two point charges?

Accepted Answer

$$F = k \dfrac{q_1$ q_2$}{r^2$}$$

Question 6

A neutral conducting sphere is brought near a negatively charged rod. What happens to the charges in the sphere?

Accepted Answer

Negative charges in the sphere are repelled away from the rod, leaving the near side positively charged.

Question 7

Which of the following best describes the electric field at a point in space?

Accepted Answer

The force per unit charge experienced by a test charge at that point.

Question 8

A $$+2\ \mu\mathrm{C}$$ charge is placed in a uniform electric field of $$E = 5.0 	imes 10^4$\ \mathrm{N/C}. $$What is the magnitude and direction of the force on the charge?

Accepted Answer

$$F = 0.10\ \mathrm{N}$$, in the direction of the field

Question 9

Which of the following statements about electric field lines is FALSE?

Accepted Answer

Electric field lines can cross each other.

Question 10

A parallel-plate capacitor has plates separated by $$d$$ and carries charges $$+Q$$ and $$-Q. $$What is the direction of the electric field between the plates?

Accepted Answer

From the positive plate to the negative plate

Question 11

Which of the following is true about the electric field inside a conductor in electrostatic equilibrium?

Accepted Answer

It is zero.

Question 12

A conductor is grounded while a negatively charged rod is brought near it (but not touching). What is the net charge on the conductor after the rod is removed and the ground connection is broken?

Accepted Answer

The conductor is left with a net positive charge.

Question 13

Which equation defines electric flux through a surface?

Accepted Answer

$$\Phi = EA \cos 	heta$$

Question 14

Gauss’s Law relates the electric flux through a closed surface to:

Accepted Answer

The total charge enclosed by the surface.

Question 15

A point charge $$q is $$placed at the center of a spherical surface of radius $$r. $$What is the total electric flux through the surface?

Accepted Answer

$$\Phi = \dfrac{q}{\$$varepsilon_0$$}$$

Question 16

Which of the following is a property of field lines near a conductor in electrostatic equilibrium?

Accepted Answer

Field lines are perpendicular to the surface.

Question 17

A photoconductive material is exposed to light. What happens to its electrical properties?

Accepted Answer

It becomes a better conductor.

Question 18

A charged balloon sticks to a neutral wall. Which phenomenon best explains this?

Accepted Answer

Polarization of atoms in the wall.

Question 19

If the distance between two point charges is doubled, what happens to the magnitude of the electrostatic force between them?

Accepted Answer

It becomes one-fourth as large.

Question 20

Which of the following is NOT a consequence of Gauss’s Law?

Accepted Answer

The electric field inside a uniformly charged solid sphere is constant everywhere.

Chapter 19: Electric Charges, Forces, and Fields – Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards