In order to obtain an intensive property from an extensive property of a system, it is necessary to
1. multiply the extensive property by the system temperature
2. divide the extensive property by the mass of the system
3. divide the extensive property by the system energy
4. multiply the extensive property by the system volume
The temperature of an ideal gas has been changed from 300 K to 400 K by isochoric, isobaric and isentropic processes. In which of these processes did the internal energy of the gas increase the most?
1. all increases were equal
2. isentropic
3. isobaric
4. isochoric
For a given initial state of the thermodynamic system, the change in system property during the process depends only on
1. the heat exchanged during the process
2. the work exchanged during the process
3. the process path
4. the final state of the process
The formula

where: u is the specific internal energy, T is the absolute temperature, v is the specific volume, represents
1. the second law of thermodynamics in differential form
2. the total differential of the specific internal energy
3. the total differential of specific entropy
4. the first law of thermodynamics in differential form
In which of the processes from state 1 to state 2 shown in the diagram did the gas experience a greater increase in internal energy?
1. during the g process
2. during the d process
3. the increases were the same
4. not enough data to answer
Which of the following quantities cannot have the unit J/(kgꞏK)?
1. specific entropy
2. gas constant
3. specific heat
4. specific work
Which of the following statements is NOT true?
1. 1 kPa = 1000 Pa
2. 1 Pa = 1 N/m²
3. 1 MPa = 0,1 bar
4. 1 bar = 100 kPa
In a reversible thermodynamic cycle, the temperature of the fluid removing heat from the source
1. can be higher or equal to the source temperature
2. is lower than the source temperature
3. is higher than the source temperature
4. is equal to the source temperature
An additional amount of gas was pumped into a gas tank. The energy of the gas in the tank was increased by
1. the heat of the added gas
2. the enthalpy of the added gas
3. the entropy of the added gas
4. the internal energy of the added gas
A solution at 10 bar pressure consists of 2 kmole of helium and 3 kmole of oxygen. What is the partial pressure of helium in bar in the solution?

Give a number without a unit.
The internal energy of a perfect gas does NOT change during an
1. isothermal process
2. isochoric process
3. isentropic process
4. isobaric process
Point 1 of the water vapour process 1-2 is in the range of
1. wet (saturated) vapour
2. dry saturated vapour
3. superheated vapour
4. liquid
Which of the following is NOT a unit of work?
1. Paꞏm³
2. Wꞏs
3. J
4. N/m
Heat cannot spontaneously flow from a colder body to a hotter one. Which of the following laws of thermodynamics states this?
1. First law of thermodynamics
2. Second law of thermodynamics
3. Third law of thermodynamics
4. Zeroth law of thermodynamics
A refrigerator with the door open is running in a hot room. The temperature of the room
1. increases
2. drops
3. does not change
A system in which neither mass nor energy is transferred across the boundary is called
1. a closed system
2. an open system
3. an isolated system
The pressure-volume diagram shows a reversible polytropic process of an ideal gas. Which of the following events shows that work has been added to the gas during this process?
1. the pressure of the gas increased
2. heat was added to the gas
3. the volume of the gas decreased
4. the entropy of the gas increased
The temperature-entropy diagram shows a reversible polytropic process of an ideal gas. Which of the following events shows that heat has been added to the gas during this process?
1. the temperature of the gas increased
2. the entropy of the gas increased
3. work was added to the gas
4. the volume of the gas increased
A perpetual motion machine of the second kind is a machine that
1. operates without any external energy supply
2. performs all processes reversibly
3. performs the Carnot cycle
4. converts all heat input into mechanical work
The relationship p/T = const is valid for an ideal gas process which is
1. isobaric
2. isothermal
3. isochoric
4. isentropic
Which of the following formulae is NOT correct for calculating the heat in an isothermal process 1-2 of a perfect gas in a closed system?

Symbols: m mass, c_T specific heat at constant temperature, T temperature, H enthalpy, S entropy, W_1-2 work, W_p1-2 flow process work.
1. Q_1-2 = W_1-2
2. Q_1-2 = T₁ꞏ(S₂ - S₁)
3. Q_1-2 = mꞏc_Tꞏ(T₂ - T₁)
4. Q_1-2 = H₂ - H₁ + W_p1-2
During the isobaric expansion of an ideal gas, work is transferred from the gas. How has the temperature of the gas changed?
1. it could increase, decrease or remain the same, depending on the amount of work delivered
2. increased
3. not enough data to answer
4. decreased
Compression occurs when
1. the temperature of the medium rises
2. the volume of the medium decreases
3. the pressure of the medium increases
4. heat is removed from the medium
What is the specific heat at constant pressure of methane CH₄ treated as a perfect gas?

(R is the gas constant)
1. R
2. 2R
3. 3R
4. 4R
The thermal efficiency of a clockwise Carnot cycle
1. is always greater than 1
2. is equal to 1
3. can be greater than 1, equal to 1 or less than 1
4. is less than 1
7 kmol of helium He is mixed with 3 kmol of hydrogen H₂. What is the apparent molecular weight of the resulting mixture if the atomic weight of helium He is 4 and the molecular weight of H₂ is 2?
A change in temperature of 10°C is equivalent to a change in thermodynamic temperature of
1. 283 K
2. 10 K
3. 263 K
4. 100 K
Which of the following pairs of physical quantities have the same units?
1. Energy and entropy
2. Pressure and enthalpy
3. Work and enthalpy
4. Heat and temperature
The Carnot cycle has a thermal efficiency of 0.6. During one cycle, the cycle extracts 80 kJ of heat from the heat source. How many kJ is the work of the cycle?

Thermodynamics Quiz