Name: ________________________ Class: ___________________ Date: __________
Exam 2--PHYS 202--S15
Multiple Choice
Identify the choice that best completes the statement or answers the question.
1. Electric potential is a measure of:
a. energy/charge
b. momentum/charge
c. force/charge
d. force
4. The following is a plot of potential (V) versus
position (x). You release a proton at the point x=A.
What will the particle do?
2. This diagram shows a collection of charges. At
which point is the potential equal to zero?
a.
b.
c.
d.
a.
b.
c.
d.
e.
a
b
c
d
e
oscillate back and forth
remain stationary
go to the left
go to the right
5. The capacitance of a parallel-plate capacitor can be
increased by:
I. increasing the charge
II. decreasing the charge
III. increasing the plate separation
IV. decreasing the plate separation
V. decreasing the plate area
a. II & III
b. I & IV
c. only IV
d. II & V
3. 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?
6. At what point is the potential greatest?
a.
b.
c.
d.
electron
not enough information
proton
neither, they have the same KE
a.
b.
c.
d.
1
A
B
both the same
it depends on the magnitude of the charge
11. Which of these statements, about the use of
voltmeters and ammeters, is correct?
I. Voltmeters have a large resistance and are
connected in parallel.
II. Voltmeters have a small resistance and are
connected in parallel.
III. Ammeters have a large resistance and are
connected in series.
IV. Ammeters have a large resistance and are
connected in parallel.
V. Voltmeters have a small resistance and are
connected in series.
a. III only
b. I only
c. I & III
d. V only
e. II & IV
7. A parallel-plate capacitor initially has a potential
difference of 200 V and is then disconnected from
the charging battery. If the distance between the
plates is now doubled, what is the new value of the
voltage?
a. 800 V
b. 200 V
c. 400 V
d. 100 V
8. Consider this circuit. All three capacitors are
identical. What is the voltage across C 2?
C2
C1
C3
12. Two space heaters in your living room are operated
at 120 V. Heater 1 has twice the resistance of
heater 2. Which one will give off more heat?
12 V
a.
b.
c.
d.
12 V
4V
8V
6V
a.
b.
c.
d.
9. What is the equivalent capacitance of this circuit?
Heater 1
Heater 2
both will give same heat
not enough information
13. 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 3 A. Is this device Ohmic
or Non-Ohmic?
a. Ohmic
b. Non-Ohmic
c. Neither
d. Not enough information
a.
b.
c.
d.
14. A 1 volt potential difference is observed across a
10 Ω resistor. What is the current through the
resistor?
7.6 µF
12 µF
2.0 µF
14 µF
a.
b.
c.
d.
10. A flat iron is marked “120 V,600 W.” In normal
use, the current in it is:
a. 2 A
b. 4 A
c. 5 A
d. 7.2 A
e. 0.2 A
2
100 A
10 A
1A
0.1 A
Problem
15. (15 pts) Two capacitors, C 1 and C2, are in series. Each capacitor has plates with area 0.004 m 2 that are separated
by 3.54x10-8 m. One of the capacitors, C 2, has a dielectric with a constant of 2.
What is the equivalent capacitance of these capacitors?
Ceq=________
If they are connected to a 12V battery, what is the charge on each?
Q1=________
Q2=________
If you remove the dielectric, does the charge on each capacitor increase, decrease, or stay the same. Circle the
correct response below.
Q1 increases, decreases or stays the same?
Q2 increases, decreases or stays the same?
3
16. (20 pts) Consider this configuration of charges.
a) What is the electric potential at the location of the +2 nC charge?
b) How much potential energy is contained within this configuration of charges?
.
4
17. What are the current and voltage for the resistors in each of these circuit diagrams?
18. A particle is in a potential field described by this function:
V = 3y 2 x − 2xy
What is the electric field in vector notation at the point (x=1.0, y=1.0) meters?
5
19. For this circuit, find the voltage and charge for each capacitor. Also, find the equivalent capacitance and the
energy stored by C5 (the 2µF capacitor).
6
ID: A
Exam 2--PHYS 202--S15
Answer Section
MULTIPLE CHOICE
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
11.
12.
13.
14.
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
ANS:
A
B
D
C
C
A
C
B
C
C
B
B
B
D
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
REF: S15
REF: S15
REF: S15
REF: S15
REF: S15
REF: S15
REF: S15
PROBLEM
15. ANS:
.
PTS: 1
16. ANS:
.
PTS: 1
17. ANS:
.
PTS: 1
18. ANS:
.
PTS: 1
19. ANS:
.
PTS: 1
1