Ch 22: Gauss's Law Flashcards
What is the general premise of Gauss’s Law?
Given any general distribution of charge, we surround it with an imaginary surface that encloses the charge. Then we look at the electric field at various points on this imaginary surface. Gauss’s Law is a relationship between the field at all the points on the surface and the total charge enclosed within the surface.
A positive charge produces an ___ electric flux.
outward
A negative charge produces an ___ electric flux.
inward
What are the three cases in which there is zero net charge inside a box and no net electric flux through the surface?
1)an empty box w/ no charge inside box, 2) a box containing one positive and one equal-magnitude negative point charge, and 3)an empty box immersed in a uniform electric field
The net electric flux due to a single point charge inside the box is independent of ____ and depends only on ____.
the size of the box; the net charge inside the box
T/F: Charges outside the surface give an electric flux through the surface.
FALSIES
T/F: Doubling the size of the enclosed charge doubles the flux.
QUITE TRUE QUITE TRUE
T/F: Doubling the dimensions of the box doubles the flux.
FALSE
What is the formula for electric flux of a uniform electric field?
Φ = EAcos ϕ
(the dot product of E and A; the portion of the electric field perpendicular to the area
Increasing the area ___(increases/decreases) the flux.
increases
Increasing the electric field ___(increases/decreases) the flux.
increases
What are the units for flux?
1 Nm²/C
What is the formula for flux over a nonuniform electric field?
⌠EcosϕdA; the surface integral of E; this is the average value of the perpendicular component of the electric field, multiplied by the area of the surface
Gauss’s law is completely equivalent to ___.
Coulomb’s law
Gauss’s law states ___.
the total electric flux through any closed surface is proportional to the total/net electric charge inside the surface