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

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
by

1 Answer

Answer :

Ans: c
by
selected by

Related questions

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

Reducing suction pressure in refrigeration cycle (a) lowers evaporation temperature (b) increases power required per ton of refrigeration (c) lowers compressor capacity because vapour is lighter (d) all of the above.

Description : Reducing suction pressure in refrigeration cycle (a) lowers evaporation temperature (b) increases power required per ton of refrigeration (c) lowers compressor capacity because vapour is lighter (d) all of the above.

Last Answer : Ans: d

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

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

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 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

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

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

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

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

In a refrigeration cycle, the flow of refrigerant is controlled by (a) compressor (b) condenser (c) evaporator (d) expansion valve

Description : In a refrigeration cycle, the flow of refrigerant is controlled by (a) compressor (b) condenser (c) evaporator (d) expansion valve

Last Answer : Ans: d

Aqua ammonia is used as refrigerant in the following type of refrigeration system (a) compression (b) direct (c) indirect (d) absorption

Description : Aqua ammonia is used as refrigerant in the following type of refrigeration system (a) compression (b) direct (c) indirect (d) absorption

Last Answer : Ans: d

Refrigeration in aeroplanes usually employs the following refrigerant (a) Co2 (b) Freon-11 (c) Freon-22 (d) Air

Description : Refrigeration in aeroplanes usually employs the following refrigerant (a) Co2 (b) Freon-11 (c) Freon-22 (d) Air

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

When dry bulb temperature (DBT) and wet bulb temperature (WBT) are measured, greater the difference between DBT and WBT, A. greater the amount of water vapour held in the mixture B. smaller the amount of water vapour held in the mixture C. same the amount of water vapour held in the mixture D. none of the above

Description : When dry bulb temperature (DBT) and wet bulb temperature (WBT) are measured, greater the difference between DBT and WBT, A. greater the amount of water vapour held in the mixture B. smaller the amount of ... the mixture C. same the amount of water vapour held in the mixture D. none of the above

Last Answer : ANSWER : 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 off refrigerant is dry saturated vapour (a) after passing through the condenser (b) before passing through the condenser (c)before entering the expansion valve (d) before entering the compressor

Description : In vapour compression cycle the condition off refrigerant is dry saturated vapour (a) after passing through the condenser (b) before passing through the condenser (c)before entering the expansion valve (d) before entering the compressor

Last Answer : Ans: D

In vapour compression cycle the condition of refrigerant is superheated vapour (a) after passing through the condenser (b) before passing through the condenser (c) after passing through the expansion or throttle valve (d) beforeentering the expansion valve

Description : In vapour compression cycle the condition of refrigerant is superheated vapour (a) after passing through the condenser (b) before passing through the condenser (c) after passing through the expansion or throttle valve (d) beforeentering the expansion valve

Last Answer : Ans: b

In vapour compression cycle, the condition of refrigerant is very wet vapour (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 very wet vapour (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: c

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

Most of the domestic refrigerators work on the following refrigeration system (a) vapour compression (b) vapour absorption (c) carnot cycle (d) electrolux refrigerator

Description : Most of the domestic refrigerators work on the following refrigeration system (a) vapour compression (b) vapour absorption (c) carnot cycle (d) electrolux refrigerator

Last Answer : Ans: a

Ammonia-absorption refrigeration cycle requires (a) very little work input (b) maximum work input (c) nearly same work input as for vapour compression cycle (d) zero work input

Description : Ammonia-absorption refrigeration cycle requires (a) very little work input (b) maximum work input (c) nearly same work input as for vapour compression cycle (d) zero work input

Last Answer : Ans: a

Vapour compression refrigeration is some what like (a) Carnot cycle (b) Rankine cycle (c) reversedCamot cycle (d) reversed Rankine cycle

Description : Vapour compression refrigeration is some what like (a) Carnot cycle (b) Rankine cycle (c) reversedCamot cycle (d) reversed Rankine cycle

Last Answer : Ans: C

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

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

At lower temperatures and pressures, the latent heat of vaporization of a refrigerant (a) decreases (b) increases (c) remains same (d) depends on other factors

Description : At lower temperatures and pressures, the latent heat of vaporization of a refrigerant (a) decreases (b) increases (c) remains same (d) depends on other factors

Last Answer : Ans: b

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

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

The benchmarking parameter for a vapour compression refrigeration system is a) kW / kg of refrigerant used b) kcal / m3 of chilled water c) BTU / Ton of Refrigeration d) kW / Ton of Refrigeration

Description : The benchmarking parameter for a vapour compression refrigeration system is a) kW / kg of refrigerant used b) kcal / m3 of chilled water c) BTU / Ton of Refrigeration d) kW / Ton of Refrigeration

Last Answer : d) kW / Ton of Refrigeration

The suction pipe diameter of refrigerating unit compressor in comparison to delivery side is (a) bigger (b) smaller (c) equal (d) smaller/bigger depending on capacity

Description : The suction pipe diameter of refrigerating unit compressor in comparison to delivery side is (a) bigger (b) smaller (c) equal (d) smaller/bigger depending on capacity

Last Answer : Ans: a

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

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

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

The leaks in a refrigeration system using Freon are detected by (a) halide torch which on detection produces greenish flame lighting (b) sulphur sticks which on detection gives white smoke (c) using reagents (d) sensing reduction in pressure.

Description : The leaks in a refrigeration system using Freon are detected by (a) halide torch which on detection produces greenish flame lighting (b) sulphur sticks which on detection gives white smoke (c) using reagents (d) sensing reduction in pressure.

Last Answer : Ans: a

Clapeyron equation is a relation between (a) temperature, pressure and enthalpy (b) specific volume and enthalpy (c) temperature and enthalpy (d) temperature, pressure, specific vapour and enthalpy.

Description : Clapeyron equation is a relation between (a) temperature, pressure and enthalpy (b) specific volume and enthalpy (c) temperature and enthalpy (d) temperature, pressure, specific vapour and enthalpy.

Last Answer : Ans: D

The ratio of partial pressure of water vapour in a mixture to the saturation pressure of water at the same temperature of the mixture is called as A. humidity B. partial humidity C. specific humidity D. relative humidity

Description : The ratio of partial pressure of water vapour in a mixture to the saturation pressure of water at the same temperature of the mixture is called as A. humidity B. partial humidity C. specific humidity D. relative humidity

Last Answer : ANSWER : D

The dew point is the: a. Dry bulb temperature on a psychrometer b. Temperature at which water vapour will start to be absorbed into the air c. Temperature below which water vapour will start to condense out of the air d. Pressure below which water vapour will start to condense out of the air e. Temperature at which water will start to evaporate

Description : The dew point is the: a. Dry bulb temperature on a psychrometer b. Temperature at which water vapour will start to be absorbed into the air c. Temperature below which water vapour will start to ... vapour will start to condense out of the air e. Temperature at which water will start to evaporate

Last Answer : Answer: C

The change in evaporator temperature in a refrigeration cycle, as compared to change in condenser temperature, influences the value of C.O.P. (a) more (b) less (c) equally. (d) unpredictable

Description : The change in evaporator temperature in a refrigeration cycle, as compared to change in condenser temperature, influences the value of C.O.P. (a) more (b) less (c) equally. (d) unpredictable

Last Answer : Ans: a

Mass flow ratio of NH3 in comparison to Freon-12 for same refrigeration load and same temperature limits is of the orderof (a) 1 : 1 (b) 1 : 9 (c) 9 : 1 (d) 1 : 3

Description : Mass flow ratio of NH3 in comparison to Freon-12 for same refrigeration load and same temperature limits is of the orderof (a) 1 : 1 (b) 1 : 9 (c) 9 : 1 (d) 1 : 3

Last Answer : Ans: b

A refrigeration cycle operates between condenser temperature of + 27°C and evaporator temperature of- 23°C. TheCarnot coefficient of performance of cycle will be (a) 0.2 (b) 1.2 (c) 5 (d) 6

Description : A refrigeration cycle operates between condenser temperature of + 27°C and evaporator temperature of- 23°C. TheCarnot coefficient of performance of cycle will be (a) 0.2 (b) 1.2 (c) 5 (d) 6

Last Answer : Ans: c

The refrigerant for a refrigerator should have (a) high sensible heat (b) high total heat (c) high latent heat (d) low latent heat

Description : The refrigerant for a refrigerator should have (a) high sensible heat (b) high total heat (c) high latent heat (d) low latent heat

Last Answer : Ans: c

Vapour lock is a. complete or partial stoppage of fuel supply due to vaporization of the fuel b. locking of carburetor due to high vapor pressure c. excess fuel supply to the engine d. supply of liquid fuel to the engine

Description : Vapour lock is a. complete or partial stoppage of fuel supply due to vaporization of the fuel b. locking of carburetor due to high vapor pressure c. excess fuel supply to the engine d. supply of liquid fuel to the engine

Last Answer : ANSWER a. complete or partial stoppage of fuel supply due to vaporization of the fuel

Moisture in freon refrigeration system causes (a) ineffective refrigeration (b) high power consumption (c) freezing automatic regulating valve (d) corrosion of whole system

Description : Moisture in freon refrigeration system causes (a) ineffective refrigeration (b) high power consumption (c) freezing automatic regulating valve (d) corrosion of whole system

Last Answer : Ans: c

In a refrigeration system, heat absorbed in comparison to heat rejected is (a) more (b) less (c) less for small capacity and more for high capacity. (d) more for small capacity and less for high capacity

Description : In a refrigeration system, heat absorbed in comparison to heat rejected is (a) more (b) less (c) less for small capacity and more for high capacity. (d) more for small capacity and less for high capacity

Last Answer : Ans: b

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)

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

Which of the following is not a desirable property of a refrigerant (a) highmisibility with oil (b) low boiling point (c) good electrical conductor (d) large latent heat

Description : Which of the following is not a desirable property of a refrigerant (a) highmisibility with oil (b) low boiling point (c) good electrical conductor (d) large latent heat

Last Answer : Ans: c