Generation of heat by friction is an example of a/an __________ change.
Isothermal
Irreversible
Adiabatic
Reversible
Correct Answer :
B. Irreversible
Related Questions
Critical compressibility factor for all substances
Are more or less constant (vary from 0.2 to 0.3)
Vary as square of the absolute temperature
Vary as square of the absolute pressure
None of these
The third law of thermodynamics states that the
Heat capacity of a crystalline solid is zero at absolute zero temperature
Heat transfer from low temperature to high temperature source is not possible without external work
Gases having same reduced properties behaves similarly
None of these
Joule-Thomson co-efficient is defined as
μ = (∂P/∂T)H
μ = (∂T/∂P)H
μ = (∂E/∂T)H
μ = (∂E/∂P)H
Claude's liquefaction process employs the cooling of gases by
Expansion in an engine
Following a constant pressure cycle
Throttling
None of these
The Joule-Thomson co-efficient is defined as (∂T/∂P)H. Its value at the inversion point is
∞
1
0
-ve
All gases except __________ shows a cooling effect during throttling process at atmospheric temperature and pressure.
Oxygen
Nitrogen
Air
Hydrogen
Pick out the correct equation relating 'F' and 'A'.
F = A + PV
F = E + A
F = A - TS
F = A + TS
Second law of thermodynamics is concerned with the
Amount of energy transferred
Direction of energy transfer
Irreversible processes only
Non-cyclic processes only
Pick out the wrong statement.
Activity co-efficient is dimensionless.
In case of an ideal gas, the fugacity is equal to its pressure.
In a mixture of ideal gases, the fugacity of a component is equal to the partial pressure of the component.
The fugacity co-efficient is zero for an ideal gas
In an irreversible process
Tds = dE - dW = 0
dE - dW - Tds = 0
Tds - dE + dW < 0
Tds - dT + dW < 0
Equilibrium constant decreases as the temperature
Increases, for an exothermic reaction
Decreases, for an exothermic reaction
Increases, for an endothermic reaction
None of these
The number of degrees of freedom for a mixture of ice and water (liquid) are
3
2
1
0
The number of degrees of freedom at the triple point of water is
0
1
2
3
Compressibility factor for almost all the gases are approximately same at the same
Pressure and temperature
Reduced pressure and reduced temperature
Critical pressure and critical temperature
None of these
Heat evolved/absorbed during conversion of a substance from one allotropic form to another is termed as the heat of
Fusion
Vaporisation
Transition
None of these
COP of a refrigerator drawing 1 kW of power per ton of refrigeration is about
0.5
3.5
4.5
8.5
Specific __________ does not change during phase change at constant temperature and pressure.
Entropy
Gibbs energy
Internal energy
Enthalpy
Gibbs-Helmholtz equation is
ΔF = ΔH + T [∂(ΔF)/∂T]P
ΔF = ΔH - TΔT
d(E - TS) T, V < 0
dP/dT = ΔHvap/T.ΔVvap
Fugacity of a component in an ideal gas mixture is equal to the partial pressure of that component in the mixture. The fugacity of each component in a stable homogeneous solution at constant pressure and temperature __________ as its mole fraction increases.
Decreases
Decreases exponentially
Increases
Remain constant
For any system, what is the minimum number of degrees of freedom?
0
1
2
3
Clausius-Clapeyron equation is applicable to __________ equilibrium processes.
Solid-vapor
Solid-liquid
Liquid-vapor
All (A), (B) and (C)
A gas shows deviation from ideal behaviour at
Low pressure and high temperature
Low pressure and low temperature
Low temperature and high pressure
High temperature and high pressure
For a single component two phase mixture, the number of independent variable properties are
Two
One
Zero
Three
Standard temperature and pressure (S.T.P.) is
0°C and 750 mm Hg
15°C and 750 mm Hg
0°C and 1 kgf/cm2
15°C and 1 kgf/cm2
With increase in reduced temperature, the fugacity co-efficient of a gas at constant reduced pressure
Increases
Decreases
Remain same
Decreases linearly
An irreversible process
Is the analog of linear frictionless motion in machines
Is an idealised visualisation of behaviour of a system
Yields the maximum amount of work
Yields an amount of work less than that of a reversible process
Sound waves propagation in air exemplifies an __________ process.
Adiabatic
Isothermal
Isometric
None of these
y = specific heat ratio of an ideal gas is equal to
Cp/Cv
Cp/(CP-R)
1 + (R/CV)
All (A), (B) and (C)
First law of thermodynamics is mathematically stated as
dQ = dE + dW
dQ = dE - dW
dE = dQ + dW
dW = dQ + dE
Pick out the undesirable property for a good refrigerant.
High thermal conductivity
Low freezing point
Large latent heat of vaporisation
High viscosity