electric feilds (everything) Flashcards
if a charged object is a sphear you can assume all…
all its charge is in the center
what are electrical fields
force fields where a charged partical will experience a non-contact force
what is the value of constent K
what does k represent
8.99x10^9
1/4πε0
coulombs law gives the ____ of attraction or repulsion between ___ ____ _____ in a vaccume
give coulombs law equation
force, two point charges
F = KQ(1)Q(2)/r^2
if the charges are not in a vacume (or air wich is assumed to be a vaccume) then what does the F depend on. (not the equations)
(have not seen this in any questions - dont know if you need to know this)
ε - the permitivity of the meterial between them
F on Q(1) is always ____ and _____ to F on Q(2)
equal and opposite
electrical feild strenth is defined as…
force per a unit charge
test charge in electrical feilds is ____
positive
give all 4 electrical field strenth (E) equations and state when they are aplicable and give the unit
F=QE
∴Q=F/E
E=KQ/r^2
use in non-uniform feilds (radial feilds)
E=ΔV/Δr
use in non-uniform feilds (radial feilds) -(not sure)
E=V/d
use in uniform feilds (paralell plates)
NC^-1
in radial feilds E ∝
E ∝ 1/r^2
parallel plates are used to…
as…
determine the charge of a partical as a partical with initial velocity perpendicular to feild lines will experince a force parallel to the feild lines thereofre bending the partical in a parabola curve
absalute elecrical potential (v) equation
V=kQ/r
(Q can be +ve or -ve)
V = 0 at..
∞
draw V over r graphs for positive and negetive charge (can put it on 1 graph)
what is the graidient
thereofre give another equation for E
see pg128
grdient = E (electric feild strenth)
E=ΔV/Δr
draw a E over r graph
what is the area underneth
see pg 128
the ΔV
(E=ΔV/Δr ΔV=E x Δr)
