A cyclic engine exchanges heat with two reservoirs maintained at 100 and 300°C respectively. The maximum work (in J) that can be obtained from 1000 J of heat extracted from the hot reservoir is
349
651
667
1000
Correct Answer :
A. 349
Related Questions
Throttling process is a/an __________ process.
Reversible and isothermal
Irreversible and constant enthalpy
Reversible and constant entropy
Reversible and constant enthalpy
The efficiency of a Carnot heat engine operating between absolute temperatures T1 and T2 (when, T1 > T2) is given by (T1 - T2)/T1. The co-efficient of performance (C.O.P.) of a Carnot heat pump operating between T1 and T2 is given by
T1/(T1-T2)
T2/(T1-T2)
T1/T2
T2/R1
Work done may be calculated by the expression ∫ p dA for __________ processes.
Non-flow reversible
Adiabatic
Both (A) and (B)
Neither (A) nor (B)
When liquid and vapour phases of one component system are in equilibrium (at a given temperature and pressure), the molar free energy is
More in vapour phase
More in liquid phase
Same in both the phases
Replaced by chemical potential which is more in vapour phase
Minimum number of phases that exists in a system is 1. Number of chemical species in a colloidal system is
1
2
3
4
For an ideal gas, the enthalpy
Increases with rise in pressure
Decreases with rise in pressure
Is independent of pressure
Is a path function
What is the value of Joule-Thomson co-efficient for an ideal gas?
+ve
-ve
0
∞
Pick out the wrong statement.
The net change in entropy in any reversible cycle is always zero
The entropy of the system as a whole in an irreversible process increases
The entropy of the universe tends to a maximum
The entropy of a substance does not remain constant during a reversible adiabatic change
Joule-Thomson co-efficient for a perfect gas is
Zero
Positive
Negative
None of these
Gibbs phase rule finds application, when heat transfer occurs by
Conduction
Convection
Radiation
Condensation
The necessary condition for phase equilibrium in a multiphase system of N components is that the
Chemical potentials of a given component should be equal in all phases
Chemical potentials of all components should be same in a particular phase
Sum of the chemical potentials of any given component in all the phases should be the same
None of these
A change in state involving a decrease in entropy can be spontaneous, only if
It is exothermic
It is isenthalpic
It takes place isothermally
It takes place at constant volume
Which of the following is not an equation of state?
Bertholet equation
Clausius-Clapeyron equation
Beattie-Bridgeman equation
None of these
Extensive properties of a thermodynamic system depend upon the __________ of the system.
Specific volume
Temperature
Mass
Pressure
As the temperature is lowered towards the absolute zero, the value of ∂(ΔF)/∂T, then approaches
Unity
Zero
That of the heat of reaction
Infinity
The temperature at which a real gas obeys the ideal gas laws over a wide range of pressure is called __________ temperature.
Boyle
Inversion
Critical
Reduced
1m3 of an ideal gas at 500 K and 1000 kPa expands reversibly to 5 times its initial volume in an insulated container. If the specific heat capacity (at constant pressure) of the gas is 21 J/mole . K, the final temperature will be
35 K
174 K
274 K
154 K
In an ideal solution, the activity of a component equals its
Mole fraction
Fugacity at the same temperature and pressure
Partial pressure
None of these
Boyle's law for gases states that
P ∝ 1/V, when temperature is constant
P ∝ 1/V, when temperature & mass of the gas remain constant
P ∝ V, at constant temperature & mass of the gas
P/V = constant, for any gas
The first law of thermodynamics is a restatement of the law of conservation of
Mass
Energy
Momentum
None of these
Heat of reaction at constant volume is identified with __________ change.
Enthalpy
Internal energy
Either (A) or (B)
Neither (A) nor (B)
The change in __________ is equal to the reversible work for compression in steady state flow process under isothermal condition.
Internal energy
Enthalpy
Gibbs free energy
Helmholtz free energy
If two gases have same reduced temperature and reduced pressure, then they will have the same
Volume
Mass
Critical temperature
None of these
Adiabatic compression of a saturated water vapour makes it
Supersaturated
Superheated
Both (A) and (B)
Neither (A) nor (B)
The unit of fugacity is the same as that of the
Pressure
Temperature
Volume
Molar concentration
Entropy change for an irreversible isolated system is
∞
0
< 0
> 0
What happens in a reversible adiabatic compression?
Heating occurs
Cooling occurs
Pressure is constant
Temperature is constant
At a given temperature, the volume of a gas dissolved in a solvent __________ with increase in pressure.
Increases
Decreases
Remains unchanged
May increase or decrease; depends on the gas
The number of degrees of freedom for a mixture of ice and water (liquid) are
3
2
1
0
In a turbine, the fluid expands almost
Isothermally
Isobarically
Adiabatically
None of these