Why must liquid refrigerant be present for the pressure - temperature relationship to apply?

Why must liquid refrigerant be present for the pressure - temperature relationship to apply?
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Choose the wrong statement (a) Temperature of medium being cooled must be below that of the evaporator (b) Refrigerant leaves the condenser as liquid (c) All solar thermally operated absorption systems are capable only of intermittent operation (d) frost on evaporator reduces heat transfer

Description : Choose the wrong statement (a) Temperature of medium being cooled must be below that of the evaporator (b) Refrigerant leaves the condenser as liquid (c) All solar thermally operated absorption systems are capable only of intermittent operation (d) frost on evaporator reduces heat transfer

Last Answer : Ans: a

An ideal liquid refrigerant should (A) Not have a sub-atmospheric vapour pressure at the temperature in the refrigerator coils (B) Not have unduly high vapour pressure at the condenser temperature (C) Both (A) and (B) (D) Have low specific heat

Description : An ideal liquid refrigerant should (A) Not have a sub-atmospheric vapour pressure at the temperature in the refrigerator coils (B) Not have unduly high vapour pressure at the condenser temperature (C) Both (A) and (B) (D) Have low specific heat

Last Answer : (C) Both (A) and (B)

The condition of refrigerant before entering the expansion or throttle valve, in a vapour compression system (a) dry vapour (b) wet vapour (c)liquid-vapour mixture (d) high pressure saturated liquid

Description : The condition of refrigerant before entering the expansion or throttle valve, in a vapour compression system (a) dry vapour (b) wet vapour (c)liquid-vapour mixture (d) high pressure saturated liquid

Last Answer : Ans: d

The lower horizontal line of the refrigeration cycle plotted on pressure-enthalpy-diagram represents (a) condensation of the refrigerant vapour (b) evaporation of the refrigerant liquid (c) compression of the refrigerant vapour (d) metering of the refrigerant liquid

Description : The lower horizontal line of the refrigeration cycle plotted on pressure-enthalpy-diagram represents (a) condensation of the refrigerant vapour (b) evaporation of the refrigerant liquid (c) compression of the refrigerant vapour (d) metering of the refrigerant liquid

Last Answer : Ans: b

In vapour compression cycle, the condition of refrigerant is high pressure saturated liquid (a) after passing through the condenser (b) before passing through the condenser (c) after passing through the expansion or throttle valve (d) before entering the expansion valve

Description : In vapour compression cycle, the condition of refrigerant is high pressure saturated liquid (a) after passing through the condenser (b) before passing through the condenser (c) after passing through the expansion or throttle valve (d) before entering the expansion valve

Last Answer : Ans: d

Condensing temperature in a refrigerator is the temperature (a) of cooling medium (b) of freezing zone (c) of evaporator (d) at which refrigerant gas becomes liquid

Description : Condensing temperature in a refrigerator is the temperature (a) of cooling medium (b) of freezing zone (c) of evaporator (d) at which refrigerant gas becomes liquid

Last Answer : Ans: d

One of the purposes of sub-cooling the liquid refrigerant is to (a) reduce compressor overheating (b) reduce compressor discharge temperature (c) increase cooling effect (d) ensure that only liquid and not the vapour enters the expansion (throttling) valve

Description : One of the purposes of sub-cooling the liquid refrigerant is to (a) reduce compressor overheating (b) reduce compressor discharge temperature (c) increase cooling effect (d) ensure that only liquid and not the vapour enters the expansion (throttling) valve

Last Answer : Ans: d

Which of the following situations can be approximated to a steady state heat transfer system? (A) A red hot steel slab (having outside surface temperature as 1300°C) exposed to the atmospheric air at 35°C (B) 10 kg of dry saturated steam at 8 kgf/cm2 flowing through a short length of stainless steel pipe exposed to atmospheric air at 35°C (C) Boiling brine kept in open vessel when the bottom surface temperature of the vessel is maintained constant at 180°C (D) A sub-cooled refrigerant liquid at 8°C flowing at the rate of 6 Kg/minute through a copper pipe exposed to atmospheric air at 35°C

Description : Which of the following situations can be approximated to a steady state heat transfer system? (A) A red hot steel slab (having outside surface temperature as 1300°C) exposed to the atmospheric air at ... flowing at the rate of 6 Kg/minute through a copper pipe exposed to atmospheric air at 35°C

Last Answer : (B) 10 kg of dry saturated steam at 8 kgf/cm2 flowing through a short length of stainless steel pipe exposed to atmospheric air at 35°C

For proper refrigeration in a cabinet, if the temperature and vapour pressure difference between cabinet and atmosphereis high, then (a) bigger cabinet should be used (b) smaller cabinet should be used (c) perfectly tight vapour seal should be used (d) refrigerant with lower evaporation temperature should be used

Description : For proper refrigeration in a cabinet, if the temperature and vapour pressure difference between cabinet and atmosphereis high, then (a) bigger cabinet should be used (b) smaller cabinet should ... tight vapour seal should be used (d) refrigerant with lower evaporation temperature should be used

Last Answer : Ans: c

Which of the following is an undesirable characteristic of a refrigerant? (A) It should be non-explosive (B) It should have a sub-atmospheric vapor pressure at the temperature in refrigerator coils (C) Its vapor pressure at the condenser temperature should be very high (D) None of these

Description : Which of the following is an undesirable characteristic of a refrigerant? (A) It should be non-explosive (B) It should have a sub-atmospheric vapor pressure at the temperature in refrigerator coils (C) Its vapor pressure at the condenser temperature should be very high (D) None of these

Last Answer : (B) It should have a sub-atmospheric vapor pressure at the temperature in refrigerator coils

In vapour compression refrigeration system, refrigerant occurs as liquid between (a) condenser and expansion valve (b) compressor and evaporator (c) expansion valve and evaporator (d) compressor and condenser

Description : In vapour compression refrigeration system, refrigerant occurs as liquid between (a) condenser and expansion valve (b) compressor and evaporator (c) expansion valve and evaporator (d) compressor and condenser

Last Answer : Ans: c

In a flooded evaporator refrigerator, an accumulator at suction of compressor is used to (a) collect liquid refrigerant and prevent it from going to compressor (b) detect liquid in vapour (c) superheat the vapour (d) increase refrigeration effect

Description : In a flooded evaporator refrigerator, an accumulator at suction of compressor is used to (a) collect liquid refrigerant and prevent it from going to compressor (b) detect liquid in vapour (c) superheat the vapour (d) increase refrigeration effect

Last Answer : Ans: a

In refrigerator, liquid receiver is required between condenser and flow controlling device, if quantity of refrigerant for system is (a) less than 2 kg (b) more than or equal to 3.65 kg (c) more than 10 kg (d) there is no such consideration

Description : In refrigerator, liquid receiver is required between condenser and flow controlling device, if quantity of refrigerant for system is (a) less than 2 kg (b) more than or equal to 3.65 kg (c) more than 10 kg (d) there is no such consideration

Last Answer : Ans: b

In a vapour compression cycle, the refrigerant immediately after expansion valve is (a) liquid (b) sub-cooled liquid (c) saturated liquid (d) wet vapour

Description : In a vapour compression cycle, the refrigerant immediately after expansion valve is (a) liquid (b) sub-cooled liquid (c) saturated liquid (d) wet vapour

Last Answer : Ans: d

In vapour compression cycle, the condition of refrigerant is saturated liquid (a) after passing through the condenser (b) before passing through the condenser (c) after passing through the expansion throttle valve (d) before entering the expansion valve

Description : In vapour compression cycle, the condition of refrigerant is saturated liquid (a) after passing through the condenser (b) before passing through the condenser (c) after passing through the expansion throttle valve (d) before entering the expansion valve

Last Answer : Ans: a

Which of the following is a widely used refrigerant in vapour compression refrigeration system (using large centrifugal compressor)? (A) Freon (B) Liquid sulphur dioxide (C) Methyl chloride (D) Ammonia

Description : Which of the following is a widely used refrigerant in vapour compression refrigeration system (using large centrifugal compressor)? (A) Freon (B) Liquid sulphur dioxide (C) Methyl chloride (D) Ammonia

Last Answer : (A) Freon

What sae standards must be referred to on label of approved hfc-134a refrigerant recycling machines?

Description : What sae standards must be referred to on label of approved hfc-134a refrigerant recycling machines?

Last Answer : SAE J2210 or SAE J2788

If an hfc-134a AC system still has pressure after the first refrigerant recovery process is complete additional recovery is necessary until the system vacuum level remains stable for?

Description : If an hfc-134a AC system still has pressure after the first refrigerant recovery process is complete additional recovery is necessary until the system vacuum level remains stable for?

Last Answer : 5

If an hfc-134a AC system still has pressure after the first refrigerant recovery process is complete additional recovery is necessary until the system vacuum level remains stable for?

Description : If an hfc-134a AC system still has pressure after the first refrigerant recovery process is complete additional recovery is necessary until the system vacuum level remains stable for?

Last Answer : 5

In vapour compression cycle using NH3 as refrigerant, initial charge is filled at (a) suction of compressor (b) delivery of compressor (c) high pressure side close to receiver (d) low pressure side near receiver

Description : In vapour compression cycle using NH3 as refrigerant, initial charge is filled at (a) suction of compressor (b) delivery of compressor (c) high pressure side close to receiver (d) low pressure side near receiver

Last Answer : Ans: c

A certain refrigerating system has a normal operating suction pressure of 10 kg/cm gauge and condensing pressure ofabout 67 kg/cm. The refrigerant used is (a) Ammonia (b) Carbon dioxide (c) Freon (d) Brine

Description : A certain refrigerating system has a normal operating suction pressure of 10 kg/cm gauge and condensing pressure ofabout 67 kg/cm. The refrigerant used is (a) Ammonia (b) Carbon dioxide (c) Freon (d) Brine

Last Answer : Ans: b

Highest pressure encountered in a refrigeration system should be (a) critical pressure of refrigerant (b) much below critical pressure (c) much above critical pressure (d) near critical pressure

Description : Highest pressure encountered in a refrigeration system should be (a) critical pressure of refrigerant (b) much below critical pressure (c) much above critical pressure (d) near critical pressure

Last Answer : Ans: b

The vapour pressure of refrigerant should be (a) lower than atmospheric pressure (b) higher than atmospheric pressure (c) equal to atmospheric pressure (d) could be anything

Description : The vapour pressure of refrigerant should be (a) lower than atmospheric pressure (b) higher than atmospheric pressure (c) equal to atmospheric pressure (d) could be anything

Last Answer : Ans: b

Intimate contact occurs between the food or package and the refrigerant with ____ freezing. a. blast c. cold b. pressure d. immersion

Description : Intimate contact occurs between the food or package and the refrigerant with ____ freezing. a. blast c. cold b. pressure d. immersion

Last Answer : d. immersion

The C.O.P. of a refrigeration cycle with lowering of condenser temperature, keeping the evaporator temperatureconstant, will (a) increase (b) decrease (c) may increase or decrease depending on the type of refrigerant used (d) remain unaffected

Description : The C.O.P. of a refrigeration cycle with lowering of condenser temperature, keeping the evaporator temperatureconstant, will (a) increase (b) decrease (c) may increase or decrease depending on the type of refrigerant used (d) remain unaffected

Last Answer : Ans: a

The C.O.P of a refrigeration cycle with increase in evaporator temperature, keeping condenser temperature constant, will (a) increase (b) decrease (c) remain unaffected (d) may increase or decrease depending on the type of refrigerant used

Description : The C.O.P of a refrigeration cycle with increase in evaporator temperature, keeping condenser temperature constant, will (a) increase (b) decrease (c) remain unaffected (d) may increase or decrease depending on the type of refrigerant used

Last Answer : Ans: a

Choose the correct statement (a) A refrigerant should have low latent heat (b) If operating temperature of system is low, then refrigerant with low boiling point should be used (c) Pre-cooling and sub-cooling bf refrigerant are same (d) Superheat and sensible heat of a. refrigerant are same

Description : Choose the correct statement (a) A refrigerant should have low latent heat (b) If operating temperature of system is low, then refrigerant with low boiling point should be used (c) Pre-cooling and sub-cooling bf refrigerant are same (d) Superheat and sensible heat of a. refrigerant are same

Last Answer : Ans: b

In refrigerators, the temperature difference between the evaporating refrigerant and the medium being cooled should be (a) high, of the order of 25° (b) as low as possible (3 to 11°C) (c) zero (d) any value

Description : In refrigerators, the temperature difference between the evaporating refrigerant and the medium being cooled should be (a) high, of the order of 25° (b) as low as possible (3 to 11°C) (c) zero (d) any value

Last Answer : Ans: b

Highest temperature encountered in refrigeration cycle should be (a) near critical temperature of refrigerant (b) above critical temperature (c) atcritica. temperature (d) much below critical temperature

Description : Highest temperature encountered in refrigeration cycle should be (a) near critical temperature of refrigerant (b) above critical temperature (c) atcritica. temperature (d) much below critical temperature

Last Answer : Ans: d

What is the critical temperature of a refrigerant ?

Description : What is the critical temperature of a refrigerant ?

Last Answer : Critical temperature is the maximum temperature of a refrigerator which it can be condensed into liquid and beyond this it remains gas irrespective of pressure applied.

Lowering of condenser temperature (keeping the evaporator temperature constant) in case of vapour compression refrigeration system results in (A) Increased COP (B) Same COP (C) Decreased COP (D) Increased or decreased COP; depending upon the type of refrigerant

Description : Lowering of condenser temperature (keeping the evaporator temperature constant) in case of vapour compression refrigeration system results in (A) Increased COP (B) Same COP (C) Decreased COP (D) Increased or decreased COP; depending upon the type of refrigerant

Last Answer : (A) Increased COP

The benchmarking parameter for air conditioning equipment is a) kW/Ton of Refrigeration b) kW/ kg of refrigerant handled c) kcal/m3 of chilled water d) Differential temperature across chiller

Description : The benchmarking parameter for air conditioning equipment is a) kW/Ton of Refrigeration b) kW/ kg of refrigerant handled c) kcal/m3 of chilled water d) Differential temperature across chiller

Last Answer : kW/Ton of Refrigeration

The benchmarking parameter for air conditioning equipment is a) kW/Ton of Refrigeration b) kW/ kg of refrigerant handled c) kcal/m3 of chilled water d) Differential temperature across chiLLER

Description : The benchmarking parameter for air conditioning equipment is a) kW/Ton of Refrigeration b) kW/ kg of refrigerant handled c) kcal/m3 of chilled water d) Differential temperature across chiLLER

Last Answer : kW/Ton of Refrigeration

Liquid "X" is at equilibrium with its vapor in a cylinder and piston apparatus. When the volume of the space above the liquid is 50 ml and the temperature 25!, the vapor pressure of "X" is 120 torr. What will the vapor pressure of "X" be when the volume above the liquid is 100 ml and the temperature 25!C? Some liquid is always present. w) 30 torr x) 60 torr y) 120 torr z) 240 torr

Description : Liquid "X" is at equilibrium with its vapor in a cylinder and piston apparatus. When the volume of the space above the liquid is 50 ml and the temperature 25!, the vapor pressure of "X" is 120 torr. What will the ... 25!C? Some liquid is always present. w) 30 torr x) 60 torr y) 120 torr z) 240 torr

Last Answer : ANSWER: Y -- 120 TORR

Explain the relationship between pressure and density inside a liquid ?

Description : Explain the relationship between pressure and density inside a liquid ?

Last Answer : Pressure at a point inside a liquid refers to the force perceived perpendicular to each area around that point. p inside a liquid of density h at a point of depth h , p = depth of point x density of liquid x gravitational acceleration

Would using an old refrigerator that takes blocks of Ice as the refrigerant be better for any reason?

Description : Would using an old refrigerator that takes blocks of Ice as the refrigerant be better for any reason?

Last Answer : Energy is still used. That ice has to come from somewhere and then it has to be delivered.

Who does online testing for Refrigerant CFC certicate?

Description : Who does online testing for Refrigerant CFC certicate?

Last Answer : Need Answer

What is the best refrigerant gas?

Description : What is the best refrigerant gas?

Last Answer : Best refrigerant gas is R-290 and R600A because of its low environmental impact and excellent thermodynamics performance.

Is freon Refrigerant Harmful to the environment?

Description : Is freon Refrigerant Harmful to the environment?

Last Answer : Of course it is . Freon is a chlorofluorocarbons that causes depletion of ozone.Freon contains number of halo products like chlorine ,hydrogen bromine etc. Refrigerators are powerful source of these ... house which is causing increased temperature on earth sea level rising .ice depletion etc.

How do i check the refrigerant level of my car AC?

Description : How do i check the refrigerant level of my car AC?

Last Answer : To perfectly check your AC level you need to understand the components that makes up the unit such as compressor, condenser, evaporator. But the simplest method is to check if the air coming out ... use of gauge to check the air pressure from compressor but this needs a more expertise experience.

What is use of refrigerant gas in Air conditioner and in Refrigerator?

Description : What is use of refrigerant gas in Air conditioner and in Refrigerator?

Last Answer : Refrigerants are the common name for the chemical blend that cycles through the AC, changing from liquid to a gas as it absorbs and release heat.

What happens If a large amount of lubricant is removed from a system during refrigerant recovery?

Description : What happens If a large amount of lubricant is removed from a system during refrigerant recovery?

Last Answer : the sys has too much lubricant

What EPA rules require capture. of 80 of the refrigerant from a small appliance sealed system with a non-operating comprerssor if technicians are using?

Description : What EPA rules require capture. of 80 of the refrigerant from a small appliance sealed system with a non-operating comprerssor if technicians are using?

Last Answer : Feel Free to Answer

What degrees of superheat does a refrigerant system evaporator run?

Description : What degrees of superheat does a refrigerant system evaporator run?

Last Answer : Feel Free to Answer

How come moisture mentioned in SEA J2099 standards of refrigerant purity?

Description : How come moisture mentioned in SEA J2099 standards of refrigerant purity?

Last Answer : What is the answer ?

Where is subcooled refrigerant found?

Description : Where is subcooled refrigerant found?

Last Answer : Need answer

How do you add refrigerant to a Toyota Camry?

Description : How do you add refrigerant to a Toyota Camry?

Last Answer : Need answer

Auto air conditioning refrigerant compatibility?

Description : Auto air conditioning refrigerant compatibility?

Last Answer : All air conditioning units use Freon, a chemical that when circulated helps to keep air cool. The kind of freon used in both devices is not the same, and chemical solutions with different amounts of each are needed to get the job done.

In milk chilling plant, the usual secondary refrigerant is (a)ammonia (b)sodium silicate (c) glycol (d) brine

Description : In milk chilling plant, the usual secondary refrigerant is (a)ammonia (b)sodium silicate (c) glycol (d) brine

Last Answer : Ans: d

The coefficient of performance is the ratio of the refrigerant effect to the (a) heat of compression (b) work done by compressor (c) enthalpy increase in compressor (d) all of the above

Description : The coefficient of performance is the ratio of the refrigerant effect to the (a) heat of compression (b) work done by compressor (c) enthalpy increase in compressor (d) all of the above

Last Answer : Ans: d