WorksheetsFundamentals of Thermodynamics
Total questions: 30
Worksheet time: 15mins
Which statement best defines a thermodynamic system?
A body whose temperature is constant
The region in space containing matter whose behavior is to be investigated
Any collection of particles isolated from surroundings
Only a closed container with a fixed mass
Which of the following is an intensive property?
Internal energy
Enthalpy
Mass
Temperature
During a change of state, if the system is in equilibrium at each instant, what is the process called?
Steady flow process
Quasistatic process
Irreversible process
Thermodynamic cycle
Select the correct pair for Absolute pressure in a gauge-pressure situation and in a vacuum situation, respectively.
Pabs = Patm − Pg ; Pabs = Patm + vacuum
Pabs = Pg − Patm ; Pabs = Patm − vacuum
Pabs = Patm + Pg ; Pabs = Patm − vacuum
Pabs = Pg ; Pabs = vacuum
A system undergoes a closed cycle. According to the First Law of Thermodynamics, which cyclic integral equals the net work transfer?
∮ dQ
∮ dW
∮ dU
∮ dH
For a steady flow process, which equation correctly represents the energy balance known as the S.F.E.E.?
Q − W = (h2 − h1) + g(z2 − z1) + (V2 2 − V1 2)/2
Q + W = (h2 − h1) − g(z2 − z1) + (V2 2 − V1 2)/2
Q − W = (u2 − u1)
Q = (h2 − h1) + W
Which statement expresses the Clausius form of the Second Law of Thermodynamics?
Heat and work are mutually convertible without restriction in a cycle.
It is impossible to construct a device operating in a cycle that converts all heat from a single reservoir into work.
Heat cannot flow from a colder body to a hotter body without external energy.
If two bodies are separately in thermal equilibrium with a third body, they are in equilibrium with each other.
At constant temperature, which relationship correctly represents Boyle's Law for an ideal gas?
P ∝ V
P ∝ 1/V or PV = constant
V ∝ T or V/T = constant
P = m R T
Charles's Law states that at constant pressure, the volume of a gas is directly proportional to which quantity?
Absolute pressure
Absolute temperature
Molar mass
Universal gas constant
Which is the correct characteristic gas equation relating pressure, volume, mass, gas constant, and absolute temperature?
P V = m R T
P = ρ R T
P v = R T
R_u = R M
The universal gas constant R_u is defined as which product?
Specific gas constant and temperature
Molecular weight and gas constant R
Pressure and molar volume
Specific heats ratio and temperature
According to Joule's law for a perfect gas, the change in internal energy depends on which variable(s)? Use the provided relation ΔU = m C_v (T2 − T1).
Pressure only
Volume only
Temperature only
Both pressure and volume
For air, which set of values is consistent with the given data: C_p, C_v, R, and adiabatic index γ?
C_p = 1.005 kJ/kg-K, C_v = 0.715 kJ/kg-K, R = 0.287 kJ/kg-K, γ = 1.4
C_p = 0.715 kJ/kg-K, C_v = 1.005 kJ/kg-K, R = 0.287 kJ/kg-K, γ = 1.67
C_p = 1.005 kJ/kg-K, C_v = 0.287 kJ/kg-K, R = 0.715 kJ/kg-K, γ = 1.4
C_p = 0.287 kJ/kg-K, C_v = 0.715 kJ/kg-K, R = 1.005 kJ/kg-K, γ = 1.67
In an isochoric (constant volume) process for an ideal gas, which statement is correct?
Work done W = 0
Heat transfer Q = 0
Change in enthalpy dh = 0
P1V1 = P2V2 = constant
For a constant pressure (isobaric) process of an ideal gas, the general gas equation reduces to which of the following?
P1/T1 = P2/T2
V1/T1 = V2/T2
P1V1 = P2V2
T1/V1 = T2/V2
In an isothermal process of an ideal gas, which pair of expressions for work done W is valid?
W = P1V1 ln(V2/V1) and W = m R T ln(V2/V1)
W = m cV (T2 − T1) and W = m R (T2 − T1)
W = (P1V1 − P2V2)/(γ − 1) and W = m R (T1 − T2)/(γ − 1)
W = 0 only
For a reversible adiabatic (isentropic) process of an ideal gas, which of the following is true?
Q = 0 and ds = 0
Q = 0 but ds > 0
Q ≠ 0 and ds = 0
Q ≠ 0 and ds ≠ 0
Which relation is used to find the temperature ratio in a reversible adiabatic process?
T2/T1=(V1/V2)(γ−1)
T2/T1=(P2/P1)(γ−1)
T2/T1=(V1/V2)γ
T2/T1=(P2/P1)(1/γ)
In a polytropic process following PV^n = constant, which formula gives the work done between states 1 and 2?
W = (P1V1 − P2V2)/(n − 1)
W = m cV (T2 − T1)
W = m R T ln(V2/V1)
W = 0
A closed system of ideal gas undergoes an isobaric heating from T1 to T2. Which expression correctly gives the heat transfer?
Q = m cP (T2 − T1)
Q = m cV (T2 − T1)
Q = P1V1 ln(V2/V1)
Q = 0
For a polytropic process with index n, the entropy change is given by which expression?
ds = m cV (n − γ)/(n − 1) ln(T2/T1)
ds = m cP ln(T2/T1)
ds = m cV ln(T2/T1)
ds = 0 for all n
Which statement best defines an air-standard cycle as used in engine analysis?
A real engine cycle using fuel–air mixture with heat losses considered
An imaginary cycle applying idealized assumptions where air is the working medium
A refrigeration cycle operating with air as refrigerant
A closed cycle considering variable specific heats and chemical reactions
According to the air-standard assumptions listed, which of the following is NOT assumed?
Air behaves as an ideal gas with constant specific heats
Heat is supplied from an external source and rejected to a sink
There is no heat loss in the cycle and all processes are internally reversible
Air undergoes chemical change during the cycle
For the Carnot cycle operating on air-standard assumptions, the air-standard efficiency n is given by which relation in terms of temperatures?
n = 1 − (T1/T2)
n = (T1 − T2)/T1
n = (T2 − T1)/T2
n = 1/(T1 − T2)
The air-standard efficiency of the Otto cycle depends primarily on which parameter(s)?
Cut-off ratio only
Compression ratio and adiabatic index (gamma)
Maximum and minimum cycle temperatures only
Stroke volume only
In comparing the Otto and Diesel cycles, which statement is correct regarding the mode of heat addition?
Both add heat at constant pressure
Otto: constant volume; Diesel: constant pressure
Otto: constant pressure; Diesel: constant volume
Both add heat at constant volume
Which statement best defines Fuel as used in engineering thermodynamics?
A substance composed of combustible elements that liberates heat when burned in air (oxygen).
Any substance that contains carbon regardless of its ability to burn.
Only hydrocarbons that burn without leaving ash.
A substance that produces only water on combustion.
Lower Calorific Value (LCV) of a fuel is defined as the heat liberated by complete combustion of a unit quantity of fuel when:
the products are cooled to the initial temperature with condensation of vapour formed.
no condensation of vapour occurs in the products of combustion.
the reactants and products are both at 25°C and 1 atm.
excess air is supplied beyond stoichiometric.
Using Dulong’s formula, which term accounts for the net hydrogen contributing to calorific value?
H2
H2 − O2/8
O2/8 − H2
S
A gaseous fuel’s Higher Calorific Value (HCV) is to be measured in the laboratory. Which calorimeter should be selected?
Bomb (constant volume) calorimeter
Junker’s (steady flow) calorimeter
Constant pressure bomb calorimeter
Bunsen flame calorimeter
