NSAA NSAA Physics - Thermal Physics and Thermodynamics 2

Question 1

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

Accepted Answer

No heat is exchanged with the surroundings

Answer

Heat is exchanged freely with the surroundings

Answer

Temperature remains constant throughout

Answer

Pressure remains constant throughout

Question 2

A Carnot engine operates between a hot reservoir at T_H = 600 K and a cold reservoir at T_C = 300 K. What is its efficiency?

Accepted Answer

50%

Answer

25%

Answer

75%

Answer

100%

Question 3

Which statement correctly expresses the second law of thermodynamics?

Accepted Answer

The entropy of an isolated system tends to increase in irreversible processes

Answer

The total energy of an isolated system is constant

Answer

The entropy of a perfect crystal at absolute zero is zero

Answer

Systems in equilibrium have the same pressure

Question 4

The specific latent heat of vaporization of a substance is the energy required to:

Accepted Answer

Convert 1 kg of liquid to gas at constant temperature

Answer

Raise 1 kg of the substance by 1°C

Answer

Convert 1 kg of solid to liquid at constant temperature

Answer

Cool 1 kg of gas by 1°C at constant pressure

Question 5

According to the kinetic theory of gases, pressure is caused by:

Accepted Answer

Collisions of gas molecules with the container walls

Answer

Gravitational attraction between gas molecules

Answer

Intermolecular repulsion between adjacent molecules

Answer

The weight of gas molecules pressing downward

Question 6

Over one complete thermodynamic cycle, the net work done by the system equals:

Accepted Answer

The heat absorbed minus the heat rejected

Answer

The total heat absorbed by the system

Answer

The change in internal energy over the cycle

Answer

Zero, because all state variables return to their initial values

Question 7

Which thermodynamic process occurs at constant pressure?

Accepted Answer

Isobaric

Answer

Isothermal

Answer

Adiabatic

Answer

Isochoric