Question 1

Which statement best describes the First Law of Thermodynamics?

Accepted Answer

The change in internal energy of a system equals the heat added to the system minus the work done by the system.

Question 2

A gas in a container with a moveable piston undergoes an isochoric process. What is the work done by the gas?

Accepted Answer

$$W = 0$$

Question 3

During an isobaric expansion from $$V_1 to$$ $$V_2 at $$constant pressure $$p$$, what is the expression for the work done by the gas?

Accepted Answer

$$W = p(V_2$ - V_1$)$$

Question 4

In the microscopic view of work done during a volume change, what happens when the piston moves away from the gas molecule during collision?

Accepted Answer

The molecule loses kinetic energy and does positive work on the piston.

Question 5

Which thermodynamic process is characterized by no heat entering or leaving the system?

Accepted Answer

Adiabatic

Question 6

On a $$pV-$$diagram, what does the area under the curve represent?

Accepted Answer

The work done by the system

Question 7

A system undergoes a compression from $$V_1 to$$ $$V_2$$ ($$V_2$$ \u003c $$V_1) $$with varying pressure. What is the sign of the work done?

Accepted Answer

Negative

Question 8

Why must the path (process) be specified to calculate the work done in a thermodynamic process?

Accepted Answer

Because work depends on the path taken between two states, not just the states themselves.

Question 9

For a process where the volume increases from $$V_1 to$$ $$V_2 at $$constant pressure $$p_1$$, followed by a decrease in pressure from $$p_1 to$$ $$p_2 at $$constant volume $$V_2$$, what is the total work done?

Accepted Answer

$$W = p_1$(V_2$ - V_1$)$$

Question 10

In an adiabatic process, which of the following is true?

Accepted Answer

The heat added to the system is zero.

Question 11

A gas expands from $$V_1 to$$ $$V_2$$ while the pressure decreases from $$p_1 to$$ $$p_2$$ along a smooth curve. How does the work done compare to the work done along a straight path at constant pressure $$p_1$$?

Accepted Answer

The work done depends on the specific path and can be different from the constant pressure path.

Question 12

If a system undergoes a process at constant volume, what happens to the internal energy when heat is added?

Accepted Answer

The internal energy increases by the amount of heat added.

Question 13

Which equation correctly represents the infinitesimal work done by a gas during a small expansion?

Accepted Answer

$$dW = p \, dV$$

Question 14

A gas system is surrounded by diathermal walls. What does this imply?

Accepted Answer

The system can exchange heat with the surroundings.

Question 15

In the scenario where the piston moves toward the gas molecule during collision, what is the effect on the molecule's kinetic energy and the work done?

Accepted Answer

The molecule gains kinetic energy and does negative work on the piston.

Question 16

Which of the following is NOT a type of thermodynamic process discussed in the materials?

Accepted Answer

Isentropic

Question 17

If a system undergoes a process from state 1 to state 2 along three different paths on a $$pV-$$diagram, what can be said about the work done?

Accepted Answer

The work done is different for each path.

Question 18

In a real-world scenario, a car engine compresses air in a cylinder. If the compression is rapid and insulated, which thermodynamic process best describes this situation?

Accepted Answer

Adiabatic

Question 19

Which of the following best illustrates the concept of work being path-dependent in thermodynamics?

Accepted Answer

The area under the curve on a $$pV-$$diagram varies for different paths between the same states.

The First Law of Thermodynamics and Work in Thermodynamic Processes

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