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.

Question 2

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

Accepted Answer

Electrons are transferred from the glass 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

According to Coulomb’s Law, what is the force between two point charges $$q_1$$ and $$q_2$$ separated by a distance $$r in $$vacuum?

Accepted Answer

$$F = k_e \frac{q_1$ q_2$}{r^2$}$$

Question 5

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

Accepted Answer

Negative charges in the sphere move away from the rod, and positive charges are attracted toward the rod.

Question 6

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 7

If a conductor is in electrostatic equilibrium, what is the electric field inside the conductor?

Accepted Answer

It is zero.

Question 8

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

Accepted Answer

Electric field lines can cross each other.

Question 9

A parallel-plate capacitor consists of two large, flat, conducting plates with equal and opposite charges. What is the direction of the electric field between the plates?

Accepted Answer

From the positive plate to the negative plate.

Question 10

Which of the following is the correct expression for the electric flux $$\Phi_E$$ through a surface with electric field $$E$$ perpendicular to area $$A$$?

Accepted Answer

$$\Phi_E = EA$$

Question 11

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

Accepted Answer

The total charge enclosed by the surface.

Question 12

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

Accepted Answer

Positive

Question 13

Which of the following is a property of semiconductors?

Accepted Answer

Their conductivity can change with chemical composition or light exposure.

Question 14

If three point charges are placed at the corners of an equilateral triangle, how is the net force on one charge determined?

Accepted Answer

By adding the forces from the other two charges as vectors.

Question 15

Which of the following best describes the quantization of electric charge?

Accepted Answer

Electric charge exists only in integer multiples of the elementary charge $$e.$$

Question 16

A small test charge $$q is $$placed in an electric field $$E. $$What is the force $$F on $$the test charge?

Accepted Answer

$$F = qE$$

Question 17

Which of the following statements about the distribution of excess charge on a conductor is correct?

Accepted Answer

Excess charge resides only on the surface.

Question 18

A negatively charged balloon sticks to a neutral wall. What is the best explanation for this phenomenon?

Accepted Answer

The wall becomes polarized, with positive charges attracted toward the balloon.

Question 19

Which of the following is true about the electric field near a conductor with a sharp point?

Accepted Answer

The electric field is stronger at the sharp point.

Question 20

A spherical conductor carries a net charge $$Q. $$What is the electric field outside the sphere at a distance $$r$$ from the center?

Accepted Answer

$$E = \frac{1}{4\pi\$$varepsilon_0$$} \frac{Q}{r^2$}$$

Electric Charges, Forces, and Fields – Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards