Q20.1
Which statement about
these two
thermodynamic
processes is correct?
1. both processes are
reversible
2. both processes are
irreversible
3. process #1 is
reversible and process
#2 is irreversible
4. process #1 is
irreversible and process
#2 is reversible
A20.1
Which statement about
these two
thermodynamic
processes is correct?
1. both processes are
reversible
2. both processes are
irreversible
3. process #1 is
reversible and process
#2 is irreversible
4. process #1 is
irreversible and process
#2 is reversible
Q20.2
During one cycle, an automobile engine takes in 12,000 J of
heat and discards 9000 J of heat. What is the efficiency of
this engine?
1. 400%
2. 133%
3. 75%
4. 33%
5. 25%
A20.2
During one cycle, an automobile engine takes in 12,000 J of
heat and discards 9000 J of heat. What is the efficiency of
this engine?
1. 400%
2. 133%
3. 75%
4. 33%
5. 25%
Q20.3
During one cycle, an automobile engine with an efficiency
of 20% takes in 10,000 J of heat. How much work does the
engine do per cycle?
1. 8000 J
2. 6400 J
3. 2000 J
4. 1600 J
5. 400 J
A20.3
During one cycle, an automobile engine with an efficiency
of 20% takes in 10,000 J of heat. How much work does the
engine do per cycle?
1. 8000 J
2. 6400 J
3. 2000 J
4. 1600 J
5. 400 J
Q20.4
A copper pot at room temperature is filled with roomtemperature water. Imagine a process whereby the water
spontaneously freezes and the pot becomes hot. Why is
such a process impossible?
1. it violates the first law of thermodynamics
2. it violates the second law of thermodynamics
3. it violates both the first and second laws of
thermodynamics
4. none of the above
A20.4
A copper pot at room temperature is filled with roomtemperature water. Imagine a process whereby the water
spontaneously freezes and the pot becomes hot. Why is
such a process impossible?
1. it violates the first law of thermodynamics
2. it violates the second law of thermodynamics
3. it violates both the first and second laws of
thermodynamics
4. none of the above
Q20.5
A Carnot engine takes heat in from a reservoir at 400 K and
discards heat to a reservoir at 300 K.
If the engine does 12,000 J of work per cycle, how much
heat does it take in per cycle?
1. 48,000 J
2. 24,000 J
3. 16,000 J
4. 9000 J
5. none of the above
A20.5
A Carnot engine takes heat in from a reservoir at 400 K and
discards heat to a reservoir at 300 K.
If the engine does 12,000 J of work per cycle, how much
heat does it take in per cycle?
1. 48,000 J
2. 24,000 J
3. 16,000 J
4. 9000 J
5. none of the above
Q20.6
If you put an ice cube at 0°C inside a large
metal box at 70°C, the entropy of the ice
increases. In addition,
1. the entropy of the metal box is unchanged
and the total entropy increases
2. the entropy of the metal box decreases and
the total entropy decreases
3. the entropy of the metal box decreases and
the total entropy remains the same
4. the entropy of the metal box decreases and
the total entropy increases
5. none of the above
A20.6
If you put an ice cube at 0°C inside a large
metal box at 70°C, the entropy of the ice
increases. In addition,
1. the entropy of the metal box is unchanged
and the total entropy increases
2. the entropy of the metal box decreases and
the total entropy decreases
3. the entropy of the metal box decreases and
the total entropy remains the same
4. the entropy of the metal box decreases and
the total entropy increases
5. none of the above