Name: ________________________ Class: ___________________ Date: __________
Exam 1--PHYS 202--Spring 2013
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____
1. A metallic object holds a charge of −3.8 × 10−6 C. What total number of electrons does this represent?
____
a. 2.4 × 1013
b. 1.6 × 1014
c. 6.1 × 1013
d. 4.2 × 1014
2. Which of these statements is true about charging by induction?
____
____
a. it can not be done to conductors
b. it can only occur with protons
c. it does not require contact between two charged objects
d. it causes a bigger charge than charge by conduction
3. Which of the following best characterizes electrical insulators?
a. electric charges move freely within the material
b. they are good heat conductors
c. they have a high tensile strength
d. charges in the material don't move
4. Two charges, +Q and −Q, are located two meters apart and there is a point along the line that is equidistant
from the two charges as indicated. Which vector best represents the direction of the electric field at that
point?
a.
b.
c.
d.
Vector EA
Vector EB
Vector EC
The electric field at that point is zero.
1
Name: ________________________
____
____
____
5. Two point charges are 4 cm apart. They are moved to a new separation of 2 cm. By what factor does the
resulting mutual force between them change?
a. 2
b. 1/2
c. 1/4
d. 4
6. In this figure, a negative charge, which is initially travelling in the +y direction, enters an electric field. The
charge curves to the left, as shown by the arrow in the figure. What is the direction of the electric field that
causes this motion.
a. -x
d. +z
b. +x
e. +y
c. -y
7. Electric field is dimensionally equivalent to which of the following?
a. N⋅m2/C2
b. N/C2
c. N/C
d. N⋅m/C
2
Name: ________________________
____
____
8. This figure shows two charges and their electric field lines. If the charge on the right has a magnitude of 10
µC, what is the sign and magnitude of the left charge?
a. -4 µC
d. -10 µC
e. +6 µC
b. -2.5 µC
c. +10 µC
9. Consider this configuration of charges. Which vector best represents the net force acting on the bottom
charge?
a.
b.
c.
a
b
c
d.
e.
3
d
e
Name: ________________________
____ 10. Consider this circuit. All three capacitors are identical. What is the voltage across C 1?
C2
C1
C3
12 V
a. 12 V
c. 6 V
b. 4 V
d. 8 V
____ 11. This diagram shows a collection of charges. At which point is the potential equal to zero?
a.
b.
c.
a
b
c
d.
e.
4
d
e
Name: ________________________
____ 12. At what point is the potential greatest?
a.
b.
A
B
c.
d.
both the same
it depends on the magnitude of the
charge
____ 13. Two pieces of copper wire are the same diameter. The length of wire A is twice that of wire B. How do
their resistances compare?
a. RA=RB
d. RA=2RB
b. RA=½RB
e. RA=4RB
c. RA=¼RB
____ 14. When you apply a potential of 3 V to a particular electrical device, the current in 2 A. When you apply 6V,
the current is 4 A. Is this device Ohmic or Non-Ohmic?
a. Ohmic
c. Neither
b. Non-Ohmic
d. Not enough information
____ 15. Which of these has the greater current, a incandescent light bulb (60 W) or a bathroom heater (1000 W)?
a.
b.
bulb
both the same
c.
5
heater
Name: ________________________
Problem
16. (20 pts) Consider the following circuit. Find the equivalent capacitance and the voltage and charge on each
capacitor.
Ceq=
V1=
Q1=
V2=
Q2=
V3=
Q3=
V4=
Q4=
V5=
Q5=
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Name: ________________________
17. (20 pts) a) What is the electric field in vector notation at the point (x=1.0, y=1.0) meters if the
electric potential is given by V = 2yx 2 − 3y, where V is in volts and x & y are in meters?
b) An electron is placed at the point ( 1.0 i + 1.0 j) and then released. What is the velocity, in vector
notation, of the electron after t=1x10-5 s? (Assume that the electric field remains constant as the
electron moves.)
.
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Name: ________________________
18. (10 pts) Consider this circuit and answer the following questions:
b) What is the voltage for each resistor?
V1=_______________
V2=_______________
b) What is the resistance for each resistor?
R1=_______________
R1=_______________
c) What is the current for each resistor?
I1=_______________
I2=_______________
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Name: ________________________
19. (20 pts) Two charges are arranged on the vertices of this equilateral triangle as shown.
a) What is the potential at the top of the triangle (where the smiley face is)?
b) How much work is required to place a charge of 3µC at the top of the triangle (where the smiley face is)?
.
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ID: A
Exam 1--PHYS 202--Spring 2013
Answer Section
MULTIPLE CHOICE
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
15.
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
A
C
D
A
D
B
C
A
B
D
B
A
D
A
C
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
PTS:
1
1
1
1
1
1
1
1
1
1
1
1
1
1
1
DIF: 2
TOP: 15.4 The Electric Field
DIF: 1
TOP: 15.4 The Electric Field
PROBLEM
16. ANS:
.
PTS: 1
17. ANS:
.
PTS: 1
18. ANS:
.
PTS: 1
19. ANS:
.
PTS: 1
1