MCQ
841. The value of n = 1 in the polytropic process indicates it to be-
Reversible process
Isothermal process
Adiabatic process
Irreversible process
842. In vapour compression cycle, the condition of refrigerant is saturated liquid-
after passing through the condenser
after passing through the condenser
after passing through the expansion throttle valve
before entering the expansion valve
843. In vapour compression cycle using NH, as refrigerant, initial charge is filled at-.
suction of compressor
delivery of compressor
high pressure side close to receiver
low pressure side near receiver
844. Which of the following parameters is constant for a mole for most of the gases at a given temperature and pressure?
Enthalpy
Volume
Mass
Entropy
845. The same volume of all gases would represent their-
Densities
Specific weights
Molecular weights
Gas characteristic constants
846. The specific heat of air increases with increase in-
Temperature
Pressure
Both pressure and temperature
Variation of its constituents
847. When a gas is heated change takes place in.
Pressure
Volume
Temperature
All of these
848. The lower horizontal line of the refrigeration cycle plotted on pressure-enthalpy-diagram represents--
condensation of the refrigerant vapour
evaporation of the refrigerant liquid
compression of the refrigerant vapour
meltering of the refrigerant liquid
849. Change in enthalpy of a system is the heat supplied at-
Constant pressure
Constant temperature
Constant volume
Constant entropy
850. Work done in an adiabatic process between a given pair of end states depends on-
The end states only
particular adiabatic process
The value of index n
The value of heatt ransferred
851. An isolated system is one in which-
Mass does not cross boundaries of the system, though energy may do so
Neither mass nor energy crosses the boundaries of the system
Both energy and mass cross the boundaries of the system
Mass crosses the boundary but not the energy
852. pick up incorrect statement-the
lithium bromide used in vapour absorption cycle is nonvolatile
lithium bromide plant can't operate below 0 °C
a separator is used in lithium bromide plant to remove the unwanted water vapour by condensing
concentration of solution coming out of lithium bromide generator is more in comparison to that entering the generator
853. A heat exchange process in which the product of pressure and volume Remains constant is known as-
Heat exchange process
Throttling process
Isentropic process
Hyperbolic process
854. To convert volumetric analysis to gravimetric analysis, the relative volume of each constituent of the flue gases is-
Divided by its molecular weight
Multiplied by its molecular weight
Multiplied by its density
Multiplied by its specific weight
855. Mass flow ratio of NH3 in comparison to Freon-12 for same refrigeration load and same temperature limits is of the order of-
1:1
9:1
1:9
1:3
856. Clapeyron equation is applicable for registration at—
saturation point of vapour
saturation point of liquid
sublimation temperature
triple point
857. Air conditioning means--
heating
cooling
dehumidifying
all of these
858. Freon group of refrigerants are-.
inflammable
toxic
non-inflammable and toxic
non-toxic and non-inflammable
859. If a gas vapour is allowed to expand through a very minute aperture, then such a process is known as-
Free expansion
Hyperbolic expansion
Adiabatic expansion
Throttling
860. Ammonia is-.
non-toxic
non-inflammable
toxic and non-inflammable
highly toxic and inflammable