MCAT physics chapter 6 electrostatics

Terms

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electrostatics is the study of?
stationary or static charges and forces betw them
the force that exists betw stat charges is called the?
electrostatic force
si unit of charge is?
coulomb
e=?
1.60 X 10^-19
t or f

e= -q
t
coulombs law is?
F=K (q1q2/r^2)
coulombs law gives the magnitude of the force of q1 on?
q2. and the force of q2 on q1
coulombs constant is?
1/4PI Eo= 8.99 X 10^9 Nm^2/C^2
Eo=
8.85 X 10 ^-12C2/N(M^2)
when the distance betw 2 charges is doubled, the force is?
reduced to 1/4 of the original force
comparing the electrostatic and gravitational force betw 2 charges you can use?
newtons law and coulombs law
every electric charge sets up a ?
sorrounding electric field
How do you detect an electric field?
by the force it exerts on other electric charges
electric field is def as?
force on a stationary positive test charge qo divided by the charge
Electric field=?
F/qo
electric field E points in what direction?
the direct of the force F on the positive charge qo.
electric field units?
newtons/coulomb or volts/meter
volts/meter is the unit for?
electric field
a charge qo in an electric field E experiences a F=?
F=qoE
a posit charge in an electr field feels a force in the?
direction of the field
a negative charge in an electr field feels a force?
in the direction opposite the field
the force on a positive test charge qo placed a dist r from a charge q is?
F=kq(qo)/R^2
equation for the electr field an any dist r from a charge q=?
E=kq/r^2
direct of the electr field vector.
it points _________ from q if q is a positive charge.
away
direct of an electr field
it points ______________ if q is a negative charge
towards
field lines of an electric field are ?
imaginary lines that represent how a positive test charge would be accelerated in the electr field.
for a collect of charges, the total electr field at a point of space is?
the vector sum of the electric field due to each charge
electr field str is stronger where field lines are?
closer together
Etot=?
Etot= Eq1 + Eq2 + Eq3 (vector sum)
t or f
volt= j/c
t
electric potential is
the amount of work needed to move a posit test charge qo from infinity to that point divided by the test charge.
t or f
V=w/qo
t
w/qo= ?
V or electric potential
the electric potent of a posit charge is a?
positive number
the electr potential of a negativ charge is?
a negat number
V electric potential has units of?
volts or j/c
j/c and what are equivalent units
volts
electric potential at a point is defined as ?
the amount of work needed to move a positive test charge qo from infinity to that point divid by test charge qo
electric potent= v=
w/qo
w/qo is the?
electric potential at a point
the electr potentail of a positive charge is a ?
positive number
the electric potential of a negat charge is a?
negative number
equation for electric field at any distance from a charge q=
E= k (q/r^2)
direction of electric field for a positive q is?
points away
electric field vector points ___________ q if its negative
toward
electric field of a ___________ points radially outward
positive charge
elect field of a ______________ points radially inwards
neg ch
____________ represent how a positive charge would be accelerated in the electric field
field lines
direction of elect field is always _______- to the field line at that point and in the __________ direction
tangent
same
where field lines are closer, the electric field is?
stronger
total electric field in a point in space is =
vector sum of the electric field due to each charge.
electr fields of separate charges add as ?
vectors
total electr potent at a point in space is the ____________ sum of electr potent due to each charge
scalar
potential difference is?
difference in potent betw 2 points
potential diff betw a and b is?
Vb-Va=Wab/qo
electrostatic force is
conservative or nonconservative?
conservative
equipotential line is?
a line for which the potential at every point is the same
potent diff betw any 2 points on an equipotent line is?
zero
equipotential lines
work depends only on?
potent diff of 2 lines and not on the path
t or f
work is done when moving a test charge qo from one point to another on an equipotential line
f
amount of work necessary to move a ch in an electr field dep only on?
potential difference
electric potential e U of q is?
U=W=qV
electic potential energy equals?
charge times electric potential
change in U+
q times change in V
electric pot e

Î”U=qÎ”V
qÎ”V
the sign of U depends on?
the signs of q and V
electric potential can be thought of as?
electric potential e per unit charge
U/q
when V is due to one other charge Q V is ?
kQ/r
when V is due to one other charge Q U can be written as?
U=kqQ/r
electric potent e of a 2 charge system is positive when you have 2 ________ charges
like
electric potent e of a 2 charge system is negative when you have 2 ________ charges
opposite
if 2 charges are the same, then U will be?
positive
If a charge of +2e and a charge of -3e are separated by a distance of 3 nm, what is the potential energy of the system?

what equation do you use?
U = k (qQ/r)
If a charge of +2e and a charge of -3e are separated by a distance of 3 nm, what is the potential energy of the system?

what is e?
e=1.6 X 10^-19
electric dipole is?
2 charges of equal magnitude and oppos signs separated by a small distance
potential at any 2 points for a dipole is?
V= k(q/r1)-k(q/r2)
V=kq(r2-r1/r1r2)
for points relatively far from the dipole you can approximate the potential equation as?
V=k(qd/r^2)cosÎ˜
V=k(qd/r^2)cosÎ˜ is used for what?
to approximate potential for a dipole
V=k(qd/r^2)cosÎ˜

qd is defined as?
the dipole moment p
what are the units for dipole moment?
c(m)
t or f
the dipole moment is a vector quantity
t
the dipole moment vector lies along?
the line conecting the charges (dipole axis) and point from the negative charge toward the positive charge
V=k(qd/r^2)cosÎ˜
can also be written in terms of dipole moment and becomes?
V=k(p/r^2)cosÎ˜
V=k(p/r^2)cosÎ˜

what is p?
the dipole moment
its equal to qd
V=k(p/r^2)cosÎ˜
for a dipole the potential is _______ at Î˜= _________
0,
90
for a dipole the plane that lies halfway betw +q and -q is called the?
perpendicular bisector of the dipole
electric dipole in a uniform external electric field
the net force the dipole feels will be?
zero
electric dipole in a uniform external electric field

the dipole feels no ___________ force but it does feel a _____________
translational force
torque or rotational force
electric dipole in a uniform external electric field

torque=
torque= f(d/2)sinθ + f(d/2)sinθ
torque=fdsinf(d/2)sinθ force can be written as?
f=qe
so torque=qEdsinθ
pEsinθ is used to figure out?
the nonzero torque about the center of the the dipole in an electric field.
p is ?
magnitude of the dipole moment
p=qd
in torque=pEsinθ what is θ
the angle the dipole moment makes with the electric field
the torque on a dipole will cause the dipole to?
reorient itself by rotating so its dipole moment p aligns with the electric field
which of the following is a unit of energy?
a. eV
b. V (m)
c. V/m
d. W
a. eV
it is just an energy unit, not a combo of others.
Given an electric dipole, the electric potential is zero

A. only at the midpoint of the dipole axis.
B. anywhere on any perpendicular bisector of the dipole axis and at
infinity.
C. anywhere on the dipole axis.
D. only for
b. anywhere on any perpendicular bisector of the dipole axis and at infinity

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