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

According to Coulomb’s Law, what is the force between two point charges $$q_1 = 2$$ 	imes $$10^{-6}$$\ \mathrm{C}$$ and q_2$ = -3 	imes 10$$^{-6}$$\ \mathrm{C}$$ separated by $$0.05\ \mathrm{m} in $$vacuum?

Accepted Answer

$$F = 21.6\ \mathrm{N}$$, attractive

Question 5

Which equation correctly defines the electric field $$E at a $$point due to a point charge $$q at a $$distance $$r$$?

Accepted Answer

$$E = \dfrac{kq}{r^2$}$$

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, and positive charges are attracted toward the rod, causing polarization.

Question 7

Which of the following best describes the direction of electric field lines?

Accepted Answer

They start at positive charges or infinity and end at negative charges or infinity.

Question 8

A parallel-plate capacitor has plates separated by $$d$$ and a uniform electric field $$E$$ between them. What is the electric flux $$\Phi$$ through a plate of area $$A if $$the field is perpendicular to the plate?

Accepted Answer

$$\Phi = EA$$

Question 9

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

Accepted Answer

The electric field is zero everywhere inside the conductor.

Question 10

A point charge $$q is $$placed at the center of a spherical conducting shell. According to Gauss’s Law, what is the total electric flux through the shell?

Accepted Answer

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

Question 11

A charged rod is brought near a neutral insulator. What is the most likely result?

Accepted Answer

The insulator becomes polarized, with its atoms rotating to align with the external field.

Question 12

Which of the following is a correct statement about the quantization of electric charge?

Accepted Answer

Electric charge exists only in multiples of the elementary charge $$e = 1.60 	imes 10$$^{-19}$$\ \mathrm{C}.$$

Question 13

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 vector addition of the forces from the other two charges (superposition principle).

Question 14

A conductor is grounded while a negatively charged rod is brought near it (but not touching). What is the final 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 15

Which of the following best describes the relationship between the density of electric field lines and the strength of the electric field?

Accepted Answer

The electric field is stronger where the field lines are denser.

Question 16

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

Accepted Answer

It becomes a conductor.

Question 17

Which of the following is the correct value for Coulomb’s constant $$k$$?

Accepted Answer

$$k = 8.99 	imes 10^9$\ \mathrm{N\,m^2$/C^2$$}$

Question 18

A spherical conductor carries excess charge. Where is this excess charge located?

Accepted Answer

On the surface of the conductor.

Question 19

Which of the following is the correct expression for Gauss’s Law?

Accepted Answer

$$\Phi = \dfrac{q_{	ext{encl}}}{\$$varepsilon_0$$}$$

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

Guida di studio - Domande di pratica

Study guide - Flashcard