Physics

# Multiple Choice

PhysicsMultiple Choice

### 12.1Zeroth Law of Thermodynamics: Thermal Equilibrium

30.
Which law of thermodynamics describes thermal equilibrium?
1. zeroth
2. first
3. second
4. third
31.

Name any two industries in which the principles of thermodynamics are used.

1. aerospace and information technology (IT) industries
2. industrial manufacturing and aerospace
3. mining and textile industries
4. mining and agriculture industries

### 12.2First law of Thermodynamics: Thermal Energy and Work

32.
What is the value of the Boltzmann constant?
1. $k equals 1.23 times 10 Superscript negative 38 Baseline upper J slash upper K$
2. $k equals 1.38 times 10 Superscript negative 23 Baseline upper J slash upper K$
3. $k equals 1.38 times 10 Superscript 23 Baseline upper J slash upper K$
4. $k equals 1.23 times 10 Superscript 38 Baseline upper J slash upper K$
33.
Which of the following involves work done BY a system?
1. increasing internal energy
2. compression
3. expansion
4. cooling
34.
Which principle does the first law of thermodynamics state?
1. the ideal gas law
2. the transitive property of equality
3. the law of conservation of energy
4. the principle of thermal equilibrium
35.
What is the change in internal energy of a system that does 20 J of work when $upper Q Subscript in Baseline equals 100 upper J$ and $upper Q Subscript out Baseline equals 50 upper J$?
1. $20 upper J$
2. $30 upper J$
3. $50 upper J$
4. $100 upper J$
36.
When does a real gas behave like an ideal gas?
1. A real gas behaves like an ideal gas at high temperature and low pressure.
2. A real gas behaves like an ideal gas at high temperature and high pressure.
3. A real gas behaves like an ideal gas at low temperature and low pressure.
4. A real gas behaves like an ideal gas at low temperature and high pressure.

### 12.3Second Law of Thermodynamics: Entropy

37.
In an engine, what is the unused energy converted into?
1. internal energy
2. pressure
3. work
4. heat
38.
It is natural for systems in the universe to _____ spontaneously.
1. become disordered
2. become ordered
3. produce heat
4. do work
39.
If $upper Q$ is $120 upper J$ and $upper T$ is $350 upper K$, what is the change in entropy?
1. $0.343 upper J slash upper K$
2. $1.51 upper J slash upper K$
3. $2.92 upper J slash upper K$
4. $34.3 upper J slash upper K$
40.

Why does entropy increase during a spontaneous process?

1. Entropy increases because energy always transfers spontaneously from a dispersed state to a concentrated state.
2. Entropy increases because energy always transfers spontaneously from a concentrated state to a dispersed state.
3. Entropy increases because pressure always increases spontaneously.
4. Entropy increases because temperature of any system always increases spontaneously.
41.

A system consists of ice melting in a glass of water. What happens to the entropy of this system?

1. The entropy of the ice decreases, while the entropy of the water cannot be predicted without more specific information.
2. The entropy of the system remains constant.
3. The entropy of the system decreases.
4. The entropy of the system increases.

### 12.4Applications of Thermodynamics: Heat Engines, Heat Pumps, and Refrigerators

42.
Which equation represents the net work done by a system in a cyclic process?
1. $upper W equals StartFraction upper Q Subscript c Baseline Over upper Q Subscript h Baseline EndFraction$
2. $upper W equals upper Q Subscript h Baseline plus upper Q Subscript c$
3. $upper W equals upper E f f left-parenthesis upper Q Subscript c Baseline minus upper Q Subscript h Baseline right-parenthesis$
4. $upper W equals upper Q Subscript h Baseline minus upper Q Subscript c$
43.

Which of these quantities needs to be zero for efficiency to be 100 percent?

1. ΔU
2. W
3. Qh
4. Qc
44.

Which of the following always has the greatest value in a system having 80 percent thermal efficiency?

1. ΔU
2. W
3. Qh
4. Qc
45.

In the equation Q = QhQc, what does the negative sign indicate?

1. Heat transfer of energy is always negative.
2. Heat transfer can only occur in one direction.
3. Heat is directed into the system from the surroundings outside the system.
4. Heat is directed out of the system.
46.

What is the purpose of a heat pump?

1. A heat pump uses work to transfer energy by heat from a colder environment to a warmer environment.
2. A heat pump uses work to transfer energy by heat from a warmer environment to a colder environment.
3. A heat pump does work by using heat to convey energy from a colder environment to a warmer environment.
4. A heat pump does work by using heat to convey energy from a warmer environment to a colder environment.