Practice Test: Question Set - 07
1. In vapor compression refrigeration system, if the evaporator temperature and the condenser temperatures are -13°C and 37°C respectively, the Carnot COP will be
- (A) 5.2
- (B) 6.2
- (C) 0.168
- (D) Data insufficient, can't be found out
2. Work done in an adiabatic process between two states depends on the
- (A) Rate of heat transmission
- (B) Initial state only
- (C) End states only
- (D) None of these
3. Which one is true for a throttling process?
- (A) A gas may have more than one inversion temperatures
- (B) The inversion temperature is different for different gases
- (C) The inversion temperature is same for all gases
- (D) The inversion temperature is the temperature at which Joule-Thomson
co-efficient is infinity
4. Which is an example of closed system?
- (A) Air compressor
- (B) Liquid cooling system of an automobile
- (C) Boiler
- (D) None of these
5. While dissolving a gas into a liquid at a constant temperature, the ratio of the concentration of the gas in the solution phase and in the gaseous phase is
- (A) Infinity
- (B) Unity
- (C) Constant
- (D) Negative
6. For a reversible process involving only pressure-volume work
- (A) (dF)T, p < 0
- (B) (dF)T, p > 0
- (C) (dF)T, p = 0
- (D) (dA)T, v < 0
7. Refrigerants commonly used for domestic refrigerators are
- (A) Ethyl chloride or methyl chloride
- (B) Freon-12
- (C) Propane
- (D) NH3 or CO2
8. Gibbs-Duhem equation relates composition in liquid phase and the __________ at constant temperature & pressure.
- (A) Fugacity
- (B) Partial pressure
- (C) Activity co-efficient
- (D) All (a), (b), and (c)
9. Pick out the wrong statement.
- (A) Enthalpies of all elements in their standard
states are assumed to be zero
- (B) Combustion reactions are never endothermic in
nature
- (C) Heat of reaction at constant volume is equal to
the change in internal energy
- (D) Clausius-Clapeyron equation is not applicable to
melting process
10. Pick out the correct statement.
- (A) A real gas on expansion in vacuum gets heated up
- (B) An ideal gas on expansion in vacuum gets cooled
- (C) An ideal gas on expansion in vacuum gets heated
up
- (D) A real gas on expansion in vacuum cools down
whereas ideal gas remains unaffected
11. Which of the following is not an extensive property?
- (A) Free energy
- (B) Entropy
- (C) Refractive index
- (D) None of these
12. A reasonably general expression for vapor-liquid phase equilibrium at low to moderate pressure is φi yi P = Yi xifi° where, Φ is a vapor fugacity component, Yi is the liquid activity co-efficient and fi° is the fugacity of the pure component i. the Ki value (Yi = Ki xi) is therefore, in general a function of
- (A) Temperature only
- (B) Temperature and pressure only
- (C) Temperature, pressure and liquid
composition xi only
- (D) Temperature, pressure, liquid composition xi and
vapor composition yi
13. Air-refrigeration cycle
- (A) Is the most efficient of all refrigeration
cycles
- (B) Has very low efficiency
- (C) Requires relatively large quantities of air to
achieve a significant amount of refrigeration
- (D) Both (b) and (c)
14. Pick out the wrong statement.
- (A) Trouton's ratio of non-polar liquids is
calculated using Kistyakowsky equation
- (B) Thermal efficiency of a Carnot engine is always less than 1
- (C) An equation relating pressure, volume and
temperature of a gas is called ideal gas equation
- (D) None of these
15. The minimum number of phases that can exist in a system is
- (A) 0
- (B) 1
- (C) 2
- (D) 3
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