NSAA NSAA Physics - Thermal Physics and Thermodynamics 3

Question 1

The root mean square (rms) speed of ideal gas molecules is proportional to:

Accepted Answer

Square root of temperature √T

Answer

Temperature T

Answer

T²

Answer

Reciprocal of √T

Question 2

Which equation correctly describes the ideal gas law, where n is moles and R is the universal gas constant?

Accepted Answer

PV = nRT

Answer

P/V = nRT

Answer

PV = nR/T

Answer

P + V = nRT

Question 3

The third law of thermodynamics states that:

Accepted Answer

The entropy of a perfect crystal approaches zero as temperature approaches absolute zero

Answer

Energy of an isolated system is conserved

Answer

Entropy increases in all spontaneous processes

Answer

Systems in contact reach the same temperature

Question 4

Heat transfer by convection occurs primarily in which medium?

Accepted Answer

Fluids (liquids and gases)

Answer

Solids only

Answer

Vacuum (empty space)

Answer

Dense metals only

Question 5

An ideal gas is compressed isothermally so that its volume halves. What happens to its pressure?

Accepted Answer

Pressure doubles

Answer

Pressure remains the same

Answer

Pressure halves

Answer

Pressure quadruples

Question 6

Which of the following best describes entropy in a thermodynamic context?

Accepted Answer

A measure of the disorder or number of accessible microstates of a system

Answer

Total kinetic energy of all particles in the system

Answer

The heat capacity of the substance at constant pressure

Answer

The maximum useful work that can be extracted from the system

Question 7

A gas is compressed isothermally. The work done ON the gas is:

Accepted Answer

Positive, because an external force acts on the gas

Answer

Zero, because temperature is constant

Answer

Negative, because the gas loses energy

Answer

Equal to the change in internal energy of the gas