Chapter 12, The Laws of Thermodynamics
C
HAPTER
12
Conceptual Problems
C1. On a
PV
diagram, 2 curves are plotted, both starting at the same point (
P
1
,
V
1
) and both
ending at the same increased volume (
V
2
). One curve is for an isothermal process; the other is
for an adiabatic process. Except for the common starting point, which curve is the upper one?
a. The isothermal process curve will always be the upper one.
b. The adiabatic process curve will always be the upper one.
c. Since they start at the same point and end at the same volume, they will coincide.
d. The isothermal one will start out higher, but the adiabatic one will eventually cross it.
C2. At the dice factory, sets of novelty dice are created where a side with 7 dots replaces the
single dot side. The sides then range from 2 to 7 instead of the usually 1 to 6. Using such dice
for a game of craps, what will be the most probable roll?
C3. On a
PV
diagram, 2 curves are plotted, both starting at the same point and both ending at the
same final increased volume.
One curve is for an isothermal process; the other is for an
adiabatic process.
What does the area between these two curves represent?
C4. Three Carnot engines operate between temperature reservoirs as follows: Engine A:
T
h
=
1 300 K,
T
c
= 1 000 K; Engine B:
T
h
= 1 000 K,
T
c
= 700 K; Engine C:
T
h
= 650 K,
T
c
=
500 K. Which two engines have the same thermal efficiency?
C5. In an isovolumetric process where the pressure increases, are the heat absorbed, work done
by the system, and the change in internal energy of the system positive, negative, or zero?
a.
Q
is +,
W
is +, and
U
Δ
is +.
b.
Q
is +,
W
is
–
, and
U
Δ
is 0.
c.
Q
is +,
W
is 0, and
U
Δ
is +.
d.
Q
is
–
,
W
is 0, and
U
Δ
is
–
.
12.1 Work in Thermodynamic Processes
179
This preview has intentionally blurred sections. Sign up to view the full version.
View Full Document
Chapter 12, The Laws of Thermodynamics
1.
The volume of an ideal gas changes from 0.40 to 0.55 m
3
although its pressure remains
constant at 50 000 Pa. What work is done on the system by its environment?
2.
During an isobaric process which one of the following does not change?
3.
Area on a PV diagram has units associated with:
a. energy.
b. momentum.
c. temperature.
d. change in temperature.
4.
What is the work done on the gas as it expands
from pressure
P
1
and volume
V
1
to pressure
P
2
and
volume
V
2
along the indicated straight line?
a. (
P
1
+
P
2
)(
V
1

V
2
)/2
b. (
P
1
+
P
2
) (
V
1

V
2
)
c. (
P
1
+
P
2
) (
V
1

V
2
)/2
d. (
P
1

P
2
) (
V
1
+
V
2
)
This is the end of the preview.
Sign up
to
access the rest of the document.
 Spring '09
 COFFIN
 Thermodynamics, Energy, Entropy, The Laws of Thermodynamics

Click to edit the document details