Question 1

A disk of area $A$ is placed in a uniform electric field of magnitude $E$. The normal vector to the disk's surface makes an angle $	heta$ with the electric field. What is the electric flux $\Phi_E$ through the disk?

Accepted Answer

$\Phi_E = EA \cos 	heta$

Question 2

Two Gaussian surfaces, A and B, enclose the same positive point charge. The area of surface A is twice that of surface B. How does the total electric flux through the two surfaces compare?

Accepted Answer

The total electric flux through the two surfaces is equal.

Question 3

A particle of charge $+q$ is placed at one corner of a cube. What is the electric flux through each of the three cube faces that meet at that corner?

Accepted Answer

$\dfrac{q}{8\varepsilon_0}$

Question 4

A particle of charge $+q$ is placed at one corner of a cube. What is the electric flux through each of the other (non-corner) cube faces?

Accepted Answer

$\dfrac{q}{24\varepsilon_0}$

Question 5

Suppose a disk of area $A$ is placed in a uniform electric field $E$ such that the normal to the disk is perpendicular to the field. What is the electric flux through the disk?

Accepted Answer

$0$

Question 6

A uniform electric field $E$ points in the $+x$ direction. A flat surface of area $A$ is oriented so that its normal vector points in the $+y$ direction. What is the electric flux through the surface?

Accepted Answer

$0$

Question 7

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

Accepted Answer

$\dfrac{q}{\varepsilon_0}$

Question 8

A disk of area $A$ is placed in a uniform electric field $E$. If the disk is rotated so that the angle between the normal and the field increases from $0$ to $90^\circ$, how does the electric flux through the disk change?

Accepted Answer

It decreases from $EA$ to $0$

Question 9

A cube of side $a$ is placed in a uniform electric field $E$ parallel to one of its faces. What is the net electric flux through the cube?

Accepted Answer

$0$

Question 10

A point charge $q$ is placed outside a closed surface. What is the net electric flux through the surface?

Accepted Answer

$0$

Question 11

A disk of area $A$ is placed in a uniform electric field $E$. The normal to the disk makes an angle $60^\circ$ with the field. What is the electric flux through the disk?

Accepted Answer

$EA \cos 60^\circ$

Question 12

A point charge $q$ is placed at the center of a cube. What is the electric flux through one face of the cube?

Accepted Answer

$\dfrac{q}{6\varepsilon_0}$

Question 13

A point charge $q$ is placed at the center of a cube. What is the total electric flux through the entire cube?

Accepted Answer

$\dfrac{q}{\varepsilon_0}$

Question 14

A disk of area $A$ is placed in a uniform electric field $E$. If the disk is oriented so that the normal vector is antiparallel to the field, what is the electric flux through the disk?

Accepted Answer

$-EA$

Question 15

A point charge $q$ is placed at the center of a spherical shell of radius $r$. If the shell is a conductor, what is the electric flux through the shell?

Accepted Answer

$\dfrac{q}{\varepsilon_0}$

Question 16

A point charge $q$ is placed at the center of a cube. If the cube is replaced by a closed surface of arbitrary shape enclosing the charge, what happens to the total electric flux through the surface?

Accepted Answer

It remains $\dfrac{q}{\varepsilon_0}$

Electric Flux and Gauss's Law: Study Notes

Study Guide - Practice Questions

Study Guide - Flashcards