Download AP Physics B Electrostatics Sample MC

AP Physics B
Electrostatics
1.
To say that charge is both quantized and conserved is to
say that charges
(A) occur in infinite quantities that stay the same
throughout an electricity problem.
(B) interact with neighboring charges of opposite sign,
and all the positive charges cancel all the positive
charges.
(C) come in whole number multiples of 1 electron or
proton and that they cannot be created or destroyed.
(D) is measured in the quantity known as Coulombs, and
this fundamental quantity cannot be created or
destroyed.
(E) None of these.
2.
Conductors
(A) hold their outer, valence, electrons loosely.
(B) allow the transfer of electrons
(C) store charges on their outer surface.
(D) Have no electric field inside the conductor.
(E) All of the above.
3.
Insulators
(A) hold their own electrons strongly.
(B) must always have a neutral charge.
(C) do not restrict the flow of charges.
(D) A and B only
(E) All of these.
4.
In the Oil Drop Experiment it was determined that
(A) all the drops were negatively charged.
(B) all drops received a charge that was a multiples of
1.6×10−19 C.
(C) no values of charge were smaller than 1.6×10−19 C.
(D) all values of charge were multiples of 1.6×10−19 C.
(E) All of the above.
5.
Which of these combinations exerts an attraction force?
(A) two positive charges
(B) two negative charges
(C) a positive and a negative charge
(D) a positive and a neutral charge
(E) a negative and a neutral charge
6.
Which of these combinations exerts no force on one
another?
(A) two neutral charges
(B) a neutral charge and a positive charge
(C) a neutral charge and a negative charge
(D) two uncharged objects
(E) All of these.
7.
The electrical force acting between two charges depends
on
(A) the magnitude of the largest charge.
(B) the magnitude of both charges.
(C) the distance between the charges
(D) the magnitude of the charges and the distance
between them.
(E) None of these..
Sample MC
8.
The electrical force between charges increases when the
magnitude of
(A) charge increases and distance between them
increases.
(B) charge increases and distance between them
decreases.
(C) charge decreases and distance between them
increases.
(D) charge decreases and distance between them
decreases.
(E) There are two possible combinations of answers that
meet the criteria.
9.
The distance between two charged is halved. The force
between the charges is
(A) decreased by a factor of 4
(B) decreased by a factor of 2
(C) unaffected.
(D) increased by a factor of 2
(E) increased by a factor of 4
10. There is a force F between two like charged spheres.
The charge on one of spheres is doubled while the charge
on the other is quadrupled. The spheres are moved apart
until the distance between them is double the initial
distance. The new force between them is
(A) F/4
(B) F/2
(C) F
(D) 2F
(E) 4F
11. A +1000 C charge interacts with a –10 C charge. The
force that the –10 C charge pulls on the +1000 C charge
with is
(A) much smaller than the force that the +1000 C charge
pulls on the –10 C charge.
(B) a little smaller than the force that the +1000 C charge
pulls on the –10 C charge.
(C) the same as the force that the +1000 C charge pulls
on the –10 C charge.
(D) a little bigger than the force that the +1000 C charge
pulls on the –10 C charge.
(E) much bigger than the force that the +1000 C charge
pulls on the –10 C charge.
12. The mass of a proton is 1833 times larger than the mass of
an electron. When a proton an electron interact with each
other the oversized proton’s electric force on the electron
is
(A) many times larger than the electric force of the
electron on the proton.
(B) negligibly larger than the electric force of the
electron on the proton.
(C) exactly the same as the electric force of the electron
on the proton.
(D) negligibly smaller than the electric force of the
electron on the proton.
(E) many times smaller than the electric force of the
electron on the proton.
13. The direction of the electric field at a point in space is the
same as the direction that an imaginary (test)
(A) mass moves.
(B) positive charge moves.
(C) negative charge moves.
(D) neutral charge moves.
(E) None of these is correct.
14. Field lines
(A) extend from positive to negative.
(B) never cross.
(C) are in the direction of force on a positive charge.
(D) leave and enter surfaces perpendicular to the surface.
(E) All of these.
-Q
+Q
P
15. Charges +Q and −Q are located near a point P as
shown. What is the direction of the electric field at point
P?
(A) +x
(B) −x
(C) +y
(D) −y
(E) zero
16. A positive and a negative charge are released near each
other. As they move
(A) F increases, a increases, and v increases.
(B) F increases, a increases, and v decreases.
(C) F decreases, a decreases, and v increases.
(D) F decreases, a decreases, and v decreases.
(E) F increases, a decreases, and v decreases.
17. Two like charges are released near each other. As they
move
(A) F increases, a increases, and v increases.
(B) F increases, a increases, and v decreases.
(C) F decreases, a decreases, and v increases.
(D) F decreases, a decreases, and v decreases.
(E) F increases, a decreases, and v decreases.
18. A proton and an electron are placed between the same
charged plates. Assume the attraction to each other is
insignificant compared to the attraction to the plates.
Which of these is true?
(A) The proton and electron move in the same direction,
and the proton has a higher acceleration.
(B) The proton and electron move in the same direction,
and the electron has a higher acceleration.
(C) The proton and electron move in the opposite
directions, and the proton has a higher acceleration.
(D) The proton and electron move in the opposite
directions, and the electron has a higher acceleration.
(E) The proton and electron move in the opposite
directions, and have the same accelerations.
19. Two oppositely charged plates have a potential difference
of 6 V. Which of the following is the best answer?
(A) The negative plate is always designated as 0 V and
this will mean that the positive plate must be 6 V.
(B) The positive plate is always designated as 0 V and
this will mean that the negative plate must be 6 V.
(C) Zero volts must be in the middle, so the positive plate
is +3 V and the negative plate is –3 V.
(D) Both A and C are acceptable. Answer B is
completely backwards.
(E) Any numbering system is acceptable so long as the
positive plate has a higher potential than the negative
plate, and when the negative plates potential is
subtracted from the positive plates potential a
potential difference of 6 V is calculated.
20. Which of the following is true of the potential difference
between plates?
(A) The positive plate is always the high potential plate,
and the negative plate is always the low potential
plate.
(B) The assignment of the high and low potential
depends on whether a positive charge or negative
charge is moving between the plates. A negative
charge reverses the sign on everything in the
problem.
(C) Two points the same distance from the plates have
the same potential.
(D) Both A and B are correct.
(E) Both A and C are correct.
+q
–q
P
–q
+q
21. Four equal charges are arranged in a square as shown
above. Determine which is true regarding the electric field
and electric potential at a point P at the center of the
arrangement.
(A) E ≠ 0 and V < 0
(B) E ≠ 0 and V = 0
(C) E ≠ 0 and V > 0
(D) E = 0 and V = 0
(E) E = 0 and V > 0
22. The potential difference between two points is 12 V.
A +2 C charge is moved opposite the direction of the
electric field. Which is true?
(A) W = 24 J, ∆V = 12
(B) W = 24 J, ∆V = –12
(C) W = –24 J, ∆V = 12
(D) W = –24 J, ∆V = –12
(E) W = 0, ∆V = 0
23. The potential difference between two points is 12 V.
A –2 C charge is moved opposite the direction of the
electric field. Which is true?
(A) W = 24 J, ∆V = 12
(B) W = 24 J, ∆V = –12
(C) W = –24 J, ∆V = 12
(D) W = –24 J, ∆V = –12
(E) W = 0, ∆V = 0
24. The potential difference between two points is 12 V.
A –2 C charge is moved
perpendicular to the
electric field. Which is true?
(A) W = 24 J, ∆V = 12
(B) W = 24 J, ∆V = –12
(C) W = –24 J, ∆V = 12
(D) W = –24 J, ∆V = –12
(E) W = 0, ∆V = 0
25. An electric field is shown above. Which answer describes
the equipotential lines?
(A) Equipotential lines run in the x direction with the
highest potential at the top of the diagram.
(B) Equipotential lines run in the x direction with the
highest potential at the bottom of the diagram.
(C) Equipotential lines run in the y direction with the
highest potential at the left of the diagram.
(D) Equipotential lines run in the y direction with the
highest potential at the right of the diagram.
(E) Need more information to answer.
12 V
0V
–12 V
26. The electric potential for a region in space is shown
above. Which describes the electric field in this region?
(A) The electric field is directed in the +x direction.
(B) The electric field is directed in the –x direction.
(C) The electric field is directed in the +y direction.
(D) The electric field is directed in the –y direction.
(E) The diagram is completely wrong. Potential is never
numbered below 0 V.
1.
2.
3.
4.
5.
C
E
A
E
C
6.
7.
8.
9.
10.
E
D
B
E
D
11.
12.
13.
14.
15.
C
C
B
E
A
27. Which statement is true?
(A) A charged particle moving with the electric field
always losses potential energy.
(B) A charged particle moving with the electric field
always losses potential.
(C) A charged particle moving perpendicular to the
electric field does positive work.
(D) A charged particle moving along equipotential lines
does positive work.
(E) The answer is charge dependent. In a situation where
a proton would gain energy and potential, an electron
would lose energy and potential.
28. When two plates are oppositely charged creating a 12 V
potential difference
(A) the positive plate is the high potential plate, and often
labeled 12 V.
(B) the negative plate is the low potential plate, and often
labeled 0 V.
(C) motion perpendicular to the field does not change the
potential and is thus motion along an equipotential
lines.
(D) motion of any kind of charge toward the positive
plate raises potential and motion toward the negative
plate lowers potential.
(E) All of the above.
q
29. If you ever see a diagram remotely resembling the
diagram above (in any orientation) the equation that
should come to mind is
1
1
(A) qV = mv 2
(D) qV = mv 2
2
2
1 2
(B) qV = mv
(E) All of the above
2
1
(C) qV = mv 2
2
30. If you see words that look at all like this, “charge is
accelerated through a potential difference,” the equation
that comes to mind is
1
1
(D) qV = mv 2
(A) qV = mv 2
2
2
1 2
(B) qV = mv
(E) All of the above
2
1
(C) qV = mv 2
2
16.
17.
18.
19.
20.
A
C
D
E
E
21.
22.
23.
24.
25.
D
A
C
E
C
26.
27.
28.
29.
30.
D
B
E
E
E