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?
 VbVa=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(r2r1/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