Name: ________________________ Class: ___________________ Date: __________
ID: A
Exam 1--PHYS 202--S09
Multiple Choice
Identify the choice that best completes the statement or answers the question. Each multiple choice question is worth 2
points for a total of 20 pts.
____
1. Which force vector (labeled a-e in this figure) best represents the net force on the 2 nC charge due to the -3
and +6 nC charges?
a.
b.
c.
a
b
c
d.
e.
1
d
e
Name: ________________________
____
____
ID: A
2. This figure shows three charges. The charge q 2 has a charge of -10 nC. What is the charge of q 3?
a. +5 nC
c. +10 nC
b. -10 nC
d. +8 nC
3. This figure shows how particles a and b respond to one another and, separately, how a and c respond to one
another. Which of these statements is true:
a.
b.
a & c are opposite charges
b & c are opposite charges
c.
d.
2
a & b are like charges
b & c are like charges
Name: ________________________
____
____
ID: A
4. In this figure, a ball made of conducting material is attracted to a positively charged rod. What is the charge
of the ball?
a. negative
c. either negative or neutral
b. positive
d. either positive or negative
5. A proton and electon are in a constant E-field as shown. You release an electron and proton at a point
equidistant between the plates. Which particle has more kinetic energy when they strike the plates?
a.
b.
neither, they have the same KE
proton
c.
d.
3
electron
not enough information
Name: ________________________
ID: A
____
6. Which of these statements is true at the point P, which is at the center of this square?
____
a. Ε=0, V≠0
c. Ε≠0, V=0
d. E=0, V=0
b. Ε≠0, V≠0
7. In which of the following diagrams is the potential along the x-axis equal to zero?
____
____
a. a
d. none of these
b. b
e. all of these
c. c
8. Capacitor C1 is connected across a battery of 5V. An identical capacitor, C 2 , is connected across a battery of
2 V. Which capacitor has the most charge?
a. C1
c. both have the same charge
d. it depends on other factors.
b. C2
9. These capacitors (C 1, C2, and C3) are identical. What is the potential across C 1?
a.
b.
5V
10 V
c.
d.
4
3.33 V
30 V
Name: ________________________
ID: A
____ 10. A parallel-plate capacitor initially has a potential difference of 100 V and is then disconnected from the
charging battery. If the plate spacing is now halved (without changing Q), what is the new value of the
voltage?
a.
b.
50 V
800 V
c.
d.
5
200 V
100 V
Name: ________________________
ID: A
Problem: Each problem is worth 20 points. Choose 4 of these 5 problems. Draw an “X” across the problem you
do not want graded.
11. The charges and coordinates of two charged particles held fixed in an x-y plane are q1=+2.0 µC,
x1=3.5 cm, y1=0 cm, and q2=-3.0 µC, x2=-2.0 cm, and y2=0 cm.
Find (a) the magnitude and (b) the direction of the electrostatic force on particle 2 due to particle 1.
c) What are the coordinates of a third particle, q3=-4 µC, such that the net force on all charges is
zero?
.
6
Name: ________________________
ID: A
12. a) What is the electric field in vector notation at the point ( 0 i + 2.0 j - 3.0 k) meters if the electric
potential is given by V = 3xy 2 z − 2yz 3 + 4x 2 , where V is in volts and x, y, and z are in meters?
b) What is the magnitude and direction of the acceleration experienced by an electron in this
electric field? (The mass of an electron is 9.11x10 -31 kg)
.
7
Name: ________________________
ID: A
13. In this figure, the four particles are fixed in place as shown. The charges are q1= -1 nC, q2= +1 nC,
q3= +1 nC, and q4= +1 nC. The distance d is 3 m (d=3 m). What is the net electric field, in
unit-vector notation, at point P?
.
8
Name: ________________________
ID: A
14. In this figure, the four particles are fixed in place as shown. The charges are q1= -1 nC, q2= +1 nC,
q3=+1 nC, and q4=+1 nC. The distance d is 3 m (d=3 m). What is the potential at point P due to the
four particles if V=0 at infinity?
.
9
Name: ________________________
ID: A
15.
In this figure a 20 V battery is connected across capacitors of capacitances C1=4 µF, C2=4µF,
C3=2µF, C4=8 µF, C5=8µF, and C6=8µF.
a) What is the equivalent capacitance, Ceq? Ceq=____________
b) What is the charge stored by Ceq? Qeq=____________
c) V1=____________
d) Q3=____________ (not Q1)
e) V4=____________
f) Q4=____________
g) V5=____________
10
ID: A
Exam 1--PHYS 202--S09
Answer Section
MULTIPLE CHOICE
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
B
A
B
C
A
D
D
A
A
A
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
1
1
1
1
1
1
1
1
1
1
PROBLEM
11. ANS:
..
PTS: 1
12. ANS:
.
PTS: 1
13. ANS:
.
PTS: 1
14. ANS:
.
PTS: 1
15. ANS:
.
PTS: 1
1