In a reversed Brayton cycle, the heat is absorbed by the air during
Isentropic compression process
Constant pressure cooling process
Isentropic expansion process
Constant pressure expansion process
Correct Answer :
D. Constant pressure expansion process
Related Questions
The suction pipe diameter of refrigerating unit compressor in comparison to delivery side is
Bigger
Smaller
Equal
Smaller/bigger depending on capacity
Most of the domestic refrigerators work on the following refrigeration system
Vapour compression
Vapour absorption
Carnot cycle
Electrolux refrigerator
In a pressure enthalpy chart, the space to the left of the saturated liquid line represents
Wet vapour region
Superheated vapour region
Sub-cooled liquid region
None of these
The superheated vapour region, in a pressure enthalpy chart, is represented by the space
To the left of saturated liquid line
To the right of saturated liquid line
Between the saturated liquid line and saturated vapour line
None of the above
The specific humidity during humidification process
Remains constant
Increases
Decreases
None of these
In a bootstrap air evaporative cooling system, the evaporator is provided
Between the combustion chamber and the first heat exchanger
Between the first heat exchanger and the secondary compressor
Between the secondary compressor and the second heat exchanger
Between the second heat exchanger and the cooling turbine
The evaporator used in household refrigerators is
Frosting evaporator
Non-frosting evaporator
Defrosting evaporator
None of these
The process of under-cooling is generally brought about by
Circulating more quantity of cooling water through the condenser
Using water colder than the main circulating water
Employing a heat exchanger
Any one of the above
A human body feels comfortable when the heat produced by the metabolism of human body is equal to the
Heat dissipated to the surroundings
Heat stored in the human body
Sum of (A) and (B)
Difference of (A) and (B)
The refrigerant supplied to a compressor must be
Superheated vapour refrigerant
Dry saturated liquid refrigerant
A mixture of liquid and vapour refrigerant
None of these
Hydrogen is used in Electrolux refrigeration system so as to _________ the rate of evaporation of the liquid ammonia passing through the evaporator.
Equalise
Reduce
Increase
None of these
The thermostatic expansion valve is also called
Constant pressure valve
Constant temperature valve
Constant superheat valve
None of these
The minimum temperature to which water can be cooled in a cooling tower is
Dew point temperature of air
Wet bulb temperature of air
Dry bulb temperature of air
Ambient air temperature
In a flooded evaporator refrigerator, an accumulator at suction of compressor is used to
Collect liquid refrigerant and prevent it from going to compressor
Detect liquid in vapour
Superheat the vapour
Collect vapours
In S.J. unit, one ton of refrigeration is equal to
210 kJ/ min
21 kJ/ min
420 kJ/ min
840 kJ/ min
Reducing suction pressure in refrigeration cycle
Lowers evaporation temperature
Increases power required per ton of refrigeration
Lowers compressor capacity because vapour is lighter
All of the above
In a spray washing system, if the temperature of water is higher than the dry bulb temperature of entering air, then the air is
Heated and dehumidified
Heated and humidified
Cooled and humidified
Cooled and dehumidified
The condition of refrigerant as it leaves the compressor in a vapour compression system is
Saturated liquid
Wet vapour
Dry saturated vapour
Superheated vapour
In which of the following refrigeration system, waste heat can be effectively used?
Vapour compression cycle
Vapour absorption cycle
Air refrigeration cycle
None of these
The temperature of air recorded by a thermometer, when its bulb is surrounded by a wet cloth exposed to the air, is called
Wet bulb temperature
Dry bulb temperature
Dew point temperature
None of these
The human body feels comfortable when the heat stored in the body is
Positive
Negative
Zero
None of these
In a vapour compression system, the condition of refrigerant before entering the expansion or throttle valve is
High pressure saturated liquid
Wet vapour
Very wet vapour
Dry vapour
Where does the lowest temperature occur in a vapour compression cycle?
Condenser
Evaporator
Compressor
Expansion valve
Critical temperature is the temperature above which
A gas will never liquefy
A gas will immediately liquefy
Water will evaporate
Water will never evaporate
In a domestic vapour compression refrigerator, the refrigerant commonly used is
CO₂
Ammonia
R-12
All of these
For large tonnage (more than 200 TR) air-conditioning applications, the compressor recommended is
Reciprocating
Rotating
Centrifugal
Screw
For better C.O.P of refrigerator, the pressure range corresponding to temperature in evaporator and condenser must be
Small
High
Equal
Anything
The capillary tube, as an expansion device, is used in
Domestic refrigerators
Water coolers
Room air conditioners
All of these
The specific humidity during cooling and dehumidification
Remains constant
Increases
Decreases
None of these
Degree of saturation or percentage humidity is
The mass of water vapour present in 1 m³ of dry air
The mass of water vapour present in 1 kg of dry air
The ratio of the actual mass of water vapour in a unit mass of dry air to the mass of water vapour in the same mass of dry air when it is saturated at the same temperature and pressure.
The ratio of actual mass of water vapour in a given volume of moist air to the mass of water vapour in the same volume of saturated air at the same temperature and pressure