Free Practice Quiz Question List

3 The First Law of Thermodynamics Online Quiz Questions

Use this free practice quiz with 20 questions to review 3 The First Law of Thermodynamics, test your knowledge, and prepare for your next test or exam.

20 questions

True or false

1 point

A closed system can exchange energy with its surroundings, but mass cannot cross its boundary.

A
True
B
False

Fill in the blank

1 point

A rigid tank has no change in volume. Its moving-boundary work is .

Choose one

1 point

For a closed system, heat entering is positive and work done by the system is positive. Which equation gives the finite energy balance?

A
$\Delta E=Q+W$
B
$\Delta E=Q-W$
C
$\Delta E=W-Q$
D
$\Delta E=Q$

Written response

1 point

A closed system receives $260\ \text{kJ}$ of heat and does $75\ \text{kJ}$ of work. Its kinetic and potential energies do not change appreciably. What is its change in internal energy, in kJ?

True or false

1 point

For a complete cycle, the net heat transfer equals the net work done by the system under the stated sign convention.

A
True
B
False

Written response

1 point

An adiabatic process has no heat crossing the system boundary. What is $Q$ , in kJ?

Choose one

1 point

For a quasi-static compression, what is the sign of boundary work done by the system, using the convention that work by the system is positive?

A
Positive, because pressure is positive
B
Zero, because the system is being compressed
C
Negative, because the volume decreases
D
Positive, because work is done on the system

Choose all

1 point

A closed system is in a rigid tank, has no other work interactions, and has negligible changes in kinetic and potential energy. Select all conclusions that must follow.

A
The moving-boundary work is zero.
B
The heat transfer must be zero.
C
The internal-energy change equals the heat transfer.
D
The internal-energy change must be zero.

Fill in the blank

1 point

Complete the full closed-system energy balance: $\Delta U+$ $+$ $=Q-W$ .

Choose all

1 point

Select all statements that correctly distinguish heat, work, and internal energy for a closed system.

A
Heat and work are ways energy can cross the system boundary.
B
Internal energy is a state property.
C
The amounts of heat and work generally depend on the process path.
D
Heat is stored in a closed system as a state property.

Choose one

1 point

A system is stirred while insulated, with negligible changes in kinetic and potential energy. Using the convention that work by the system is positive, which statement best describes the effect of the work input?

A
Its internal energy decreases because work done on it is positive.
B
Its internal energy increases because work done by the system is negative.
C
Its internal energy stays constant because it is insulated.
D
Its internal energy increases only if heat enters the system.

Open ended

1 point

A closed system receives $400\ \text{kJ}$ of heat and does $120\ \text{kJ}$ of work. Its kinetic energy increases by $15\ \text{kJ}$ , while its potential energy decreases by $5\ \text{kJ}$ . Using heat positive into the system and work positive out of it, determine the change in internal energy and state whether it increases or decreases.

Choose one

1 point

Which statement correctly describes the role of the quasi-static assumption in applying the first law and calculating moving-boundary work?

A
The first law applies only to quasi-static processes.
B
The boundary-work pressure integral uses boundary pressure for a quasi-static process.
C
Boundary work is always zero unless a process is quasi-static.
D
The first law cannot describe processes that change volume.

True or false

1 point

For a closed system, heat and work are ways energy crosses the boundary, not properties stored within the system.

A
True
B
False

Choose one

1 point

Which description defines a closed system in the first-law energy balance?

A
A fixed amount of energy that cannot cross the boundary
B
A fixed amount of matter, although energy may cross the boundary
C
A fixed volume that cannot exchange either mass or energy
D
A fixed amount of matter and energy, with both unable to cross the boundary

Written response

1 point

Internal energy depends on the system's state rather than on the process path. What category of property is internal energy?

Choose one

1 point

A rigid tank undergoes a process with no work other than moving-boundary work, and its kinetic and potential energy changes are negligible. Which relation applies between the internal energy change and heat transfer?

A
$\Delta U=-Q$
B
$\Delta U=0$
C
$\Delta U=Q$
D
$\Delta U=Q-W_b$ , with $W_b$ necessarily positive

Choose one

1 point

For a quasi-static moving-boundary process, which expression gives boundary work done by the system and correctly describes its sign during compression?

A
$W_b=\int_{V_1}^{V_2}p\,dV$ ; it is negative during compression
B
$W_b=\int_{V_2}^{V_1}p\,dV$ ; it is negative during expansion
C
$W_b=p(V_1-V_2)$ for every quasi-static process, regardless of how pressure varies
D
$W_b=0$ whenever the process is quasi-static

Choose one

1 point

A system completes a cycle and returns to its initial state. Under the convention that heat entering and work done by the system are positive, what relation holds between the net heat and net work?

A
The net heat is zero, while the net work may be nonzero
B
The net work is zero, while the net heat may be nonzero
C
The net heat equals the negative of the net work
D
The net heat equals the net work

Written response

1 point

A quasi-static expansion occurs at a constant pressure of $200\ \text{kPa}$ , from $0.02\ \text{m}^3$ to $0.05\ \text{m}^3$ . What is the boundary work done by the system?