Question 1

Which of the following statements best describes the relationship between electric flux and the net charge enclosed by a Gaussian surface?

Accepted Answer

Electric flux is directly proportional to the net charge enclosed by the surface.

Question 2

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

Accepted Answer

$$\displaystyle \frac{q}{\$$varepsilon_0$$}$$

Question 3

If a closed surface encloses both a $$+2\ \mu\mathrm{C}$$ and a $$-2\ \mu\mathrm{C}$$ point charge, what is the net electric flux through the surface?

Accepted Answer

$$\displaystyle 0$$

Question 4

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

Accepted Answer

The electric field is zero everywhere inside the conductor.

Question 5

A flat surface of area $$A is $$placed in a uniform electric field $$\vec{E}$$ such that the normal to the surface makes an angle $$	heta$$ with the field. What is the electric flux through the surface?

Accepted Answer

$$\displaystyle EA\cos	heta$$

Question 6

Which of the following best explains why the net electric flux through a closed surface is independent of the size or shape of the surface?

Accepted Answer

Because the net flux depends only on the net charge enclosed, not on the surface geometry.

Question 7

A long, straight wire carries a uniform linear charge density $$\lambda. $$Using Gauss's law, what is the magnitude of the electric field at a distance $$r$$ from the wire?

Accepted Answer

$$\displaystyle \frac{\lambda}{2\pi \$$varepsilon_0$$ r}$$

Question 8

A thin, infinite non-conducting sheet has a uniform surface charge density $$\sigma. $$What is the electric field just above the surface?

Accepted Answer

$$\displaystyle \frac{\sigma}{2\$$varepsilon_0$$}$$

Question 9

A charged conducting sphere of radius $$R$$ carries a total charge $$Q. $$What is the electric field at a distance $$r \u003e R$$ from the center of the sphere?

Accepted Answer

$$\displaystyle \frac{Q}{4\pi \$$varepsilon_0$$ r^2$}$$

Question 10

A solid non-conducting sphere of radius $$R$$ has a uniform volume charge density $$\rho. $$What is the electric field at a distance $$r \u003c R$$ from the center?

Accepted Answer

$$\displaystyle \frac{\rho r}{3\$$varepsilon_0$$}$$

Question 11

Which of the following is a correct statement about the electric field at the surface of a conductor in electrostatic equilibrium?

Accepted Answer

The electric field is always perpendicular to the surface.

Question 12

A small charged object is placed inside a cavity within a neutral conductor. According to Gauss's law, what happens to the charge distribution on the conductor?

Accepted Answer

A charge equal in magnitude and opposite in sign to the object appears on the cavity surface, and an equal charge of the same sign appears on the outer surface.

Question 13

Which of the following best describes the purpose of a Faraday cage?

Accepted Answer

To shield the interior from external electric fields.

Question 14

A Van de Graaff generator is used to charge a metal shell. What principle explains why the charge resides only on the outer surface of the shell?

Accepted Answer

Gauss's law

Question 15

If a point charge is placed outside a closed Gaussian surface, what is the net electric flux through the surface?

Accepted Answer

It is zero.

Question 16

A flat surface of area $$A is $$placed edge-on to a uniform electric field $$\vec{E}. $$What is the electric flux through the surface?

Accepted Answer

$$\displaystyle 0$$

Question 17

Which of the following is NOT a valid property of Gaussian surfaces?

Accepted Answer

They must always be spherical.

Question 18

A conducting box is placed in a uniform external electric field. What is the electric field inside the box?

Accepted Answer

It is zero.

Question 19

Which of the following integrals correctly expresses the general form of Gauss's law?

Accepted Answer

$$\displaystyle \oint \vec{E} \cdot d\vec{A} = \frac{q_{	ext{enc}}}{\$$varepsilon_0$$}$$

Gauss's Law and Electric Flux: University Physics Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards