What is sensible cooling of air? A. the cooling in which sensible heat of air is removed in order to reduce temperature B. the cooling in which temperature of air is reduced without changing in its moisture content C. both a. and b. D. none of the above

What is sensible cooling of air? A. the cooling in which sensible heat of air is removed in order to reduce temperature B. the cooling in which temperature of air is reduced without changing in its moisture content C. both a. and b. D. none of the above  
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In sensible heating or cooling, A. work done remains constant B. dry bulb temperature or air remains constant C. both of the mentioned D. none of the mentioned

Description : In sensible heating or cooling, A. work done remains constant B. dry bulb temperature or air remains constant C. both of the mentioned D. none of the mentioned

Last Answer : ANSWER : A

When, H1 = Total heat of air entering the coil (heating or cooling) H2 = Total heat of air leaving the coil (heating or cooling) H3 = Total heat of air at the end of the process (humidification or dehumidification) then, the sensible heat factor (H2 – H1) / (H3 – H1) represents the process of A. cooling and humidification B. cooling and dehumidification C. heating and humidification D. heating and dehumidification

Description : When, H1 = Total heat of air entering the coil (heating or cooling) H2 = Total heat of air leaving the coil (heating or cooling) H3 = Total heat of air at the end of ... A. cooling and humidification B. cooling and dehumidification C. heating and humidification D. heating and dehumidification

Last Answer : ANSWER : C

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

The horizontal line in psychrometric chart joining the change of state of air represents A. humidification B. sensible cooling or heating C. sensible cooling or heating with humidification D. sensible cooling or heating with dehumidification

Description : The horizontal line in psychrometric chart joining the change of state of air represents A. humidification B. sensible cooling or heating C. sensible cooling or heating with humidification D. sensible cooling or heating with dehumidification

Last Answer : ANSWER : B

Dew point can be best defined as the: a. Absolute temperature at which air, upon heating, will evaporate moisture b. . Percentage of moisture that air can hold at a given temperature and pressure c. . Temperature that air will begin to evaporate moisture d. . Temperature at which air, upon cooling, becomes saturated, causing moisture to condense should the temperature drop further e. . Atmospheric pressure at which air will condense moisture

Description : Dew point can be best defined as the: a. Absolute temperature at which air, upon heating, will evaporate moisture b. . Percentage of moisture that air can hold at a given temperature ... to condense should the temperature drop further e. . Atmospheric pressure at which air will condense moisture

Last Answer : Answer: D

In sensible cooling process the relative humidity: A. decreases B. increases C. remains constant D. none of the above

Description : In sensible cooling process the relative humidity: A. decreases B. increases C. remains constant D. none of the above

Last Answer : ANSWER : B

n a chemical factory where dyes are made, wet cake at 30 OC consisting of 60% moisture is put in a dryer to obtain an output having only 5% moisture, at atmospheric pressure. In each batch about 120 kgs of material is dried. a. The quantity of moisture removed per batch. b. What is the total quantity ( sensible & latent) of heat required to evaporate the moisture, if the latent heat of water is 540 kcal/kg at atmospheric conditions, Ignore heat absorbed by the solids c. Find the quantity of steam required for the drying process (per batch), if steam at 4 kg/cm2 is used for generating hot air in the dryer and the dryer efficiency is 80%. Latent heat of steam at 4 kg/cm2 is 520 kcal/kg.

Description : n a chemical factory where dyes are made, wet cake at 30 OC consisting of 60% moisture  is put in a dryer to obtain an output having only 5% moisture, at atmospheric pressure. In  each batch about 120 ... dryer and the dryer efficiency  is 80%. Latent heat of steam at 4 kg/cm2 is 520 kcal/kg.

Last Answer : Given that   Qty of material dried per batch - 120 Kgs  Moisture at inlet - 60% a. The quantity of moisture removed per batch.  Water quantity in a wet batch - 120 x 0.6 = 72 Kgs.  Quantity of bone dry ... - 48/0.95 = 50.5 Kgs.  Equivalent water in a dry batch - 50.5 - 48 = 2.5 Kgs.

In SI engines knocking can be reduced by (a) Increasing the compression ratio (b) Increasing the cooling water temperature (c) Retarding the spark advance (d) Increasing the inlet air temperature

Description : In SI engines knocking can be reduced by (a) Increasing the compression ratio (b) Increasing the cooling water temperature (c) Retarding the spark advance (d) Increasing the inlet air temperature

Last Answer : Ans :c

Humidification is the process of addition moisture in air at A. constant wet bulb temperature B. constant dry bulb temperature C. constant latent heat D. none of the above

Description : Humidification is the process of addition moisture in air at A. constant wet bulb temperature B. constant dry bulb temperature C. constant latent heat D. none of the above

Last Answer : ANSWER : B

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

Evaporative cooling process employs a combination of cooling and humidification in which the (A) Sensible heat is added (B) Sensible heat is removed and the latent heat is added (C) Latent heat is removed (D) Sensible heat is added and latent heat is removed

Description : Evaporative cooling process employs a combination of cooling and humidification in which the (A) Sensible heat is added (B) Sensible heat is removed and the latent heat is added (C) Latent heat is removed (D) Sensible heat is added and latent heat is removed

Last Answer : Option B

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

The moisture in a refrigerant is removed by (a) evaporator (b) safety relief valve (c) dehumidifier (d) driers

Description : The moisture in a refrigerant is removed by (a) evaporator (b) safety relief valve (c) dehumidifier (d) driers

Last Answer : Ans: d

The moisture content lines in psychrometric chart are also called as A. relative humidity lines B. specific humidity lines C. both a. and b. D. none of the above

Description : The moisture content lines in psychrometric chart are also called as A. relative humidity lines B. specific humidity lines C. both a. and b. D. none of the above

Last Answer : ANSWER : B

What refers to the heat needed to change the temperature of the substances without changing its phases?  a. Latent heat  b. Sensible heat  c. Specific heat  d. entropy

Description : What refers to the heat needed to change the temperature of the substances without changing its phases?  a. Latent heat  b. Sensible heat  c. Specific heat  d. entropy

Last Answer : Sensible heat

The heat content of air is called the _____ of the air. a. Temperature b. Humidity c. Enthalpy d. Psychrometry e. Entropy

Description : The heat content of air is called the _____ of the air. a. Temperature b. Humidity c. Enthalpy d. Psychrometry e. Entropy

Last Answer : ANSWER : C

Describe any two sources of air leak in surface condenser. Also describe effect of air leak on latent heat of steam and cooling water requirements.

Description : Describe any two sources of air leak in surface condenser. Also describe effect of air leak on latent heat of steam and cooling water requirements.

Last Answer : ✓ The main sources of air leakage found in condenser are given below: 1) There is leakage of air from atmosphere at the joint of the parts which are internally under a pressure less ... hence evaporation enthalpy of steam increases therefore more amount of cooling water required in the condenser. 

The term "relative humidity" applies to a) the percentage of moisture in the air as compared to the amount of moisture the air can hold at a specific temperature b) the weight of the moisture in the air c) the dryness fraction of the air d) the amount of moisture in the air e) the amount of humidity in the air

Description : The term "relative humidity" applies to a) the percentage of moisture in the air as compared to the amount of moisture the air can hold at a specific temperature b) the weight of the moisture in the air c) ... of the air d) the amount of moisture in the air e) the amount of humidity in the air

Last Answer : ANSWER : A

Absolute or specific humidity is a) the actual mass of moisture present in a specific amount of air b) the maximum mass of moisture that a specific amount of air can hold c) the ratio of the mass of moisture contained in a specific amount of air to the maximum amount of moisture this specific amount of air can contain d) the mass of moisture present in a specific amount of air at that absolute temperature e) a specific amount of air saturated with moisture

Description : Absolute or specific humidity is a) the actual mass of moisture present in a specific amount of air b) the maximum mass of moisture that a specific amount of air can hold c) the ratio of ... a specific amount of air at that absolute temperature e) a specific amount of air saturated with moisture

Last Answer : ANSWER : A

An indication of sensible heat content in air-water vapour mixture is a) wet bulb temperature b) dew point temperature c) density of air d) dry bulb temperature

Description : An indication of sensible heat content in air-water vapour mixture is a) wet bulb temperature b) dew point temperature c) density of air d) dry bulb temperature

Last Answer : d) dry bulb temperature

A ______ is a specialized heat exchanger in which air and water are brought into direct contact with each otherin order to reduce the water's temperature. a. Cooling tower b. Heating tower c. Both d. All are wrong

Description : A ______ is a specialized heat exchanger in which air and water are brought into direct contact with each otherin order to reduce the water's temperature. a. Cooling tower b. Heating tower c. Both d. All are wrong

Last Answer : cooling tower

In a cooling tower, water becomes cool by (A) Loosing sensible heat (B) Heat transfer to surroundings (C) Vaporisation due to heat loss to air (D) Loosing latent heat

Description : In a cooling tower, water becomes cool by (A) Loosing sensible heat (B) Heat transfer to surroundings (C) Vaporisation due to heat loss to air (D) Loosing latent heat

Last Answer : (A) Loosing sensible heat

The formation of frost on cooling coils in a refrigerator (a) increases heat transfer (b) improves C.O.P. of the system (c) increases power consumption (d) reduces power consumption

Description : The formation of frost on cooling coils in a refrigerator (a) increases heat transfer (b) improves C.O.P. of the system (c) increases power consumption (d) reduces power consumption

Last Answer : Ans: c

In adiabatic evaporative cooling, heat transfer between chamber and surroundings is ____ A. zero B. high C. low D. none of the mentioned

Description : In adiabatic evaporative cooling, heat transfer between chamber and surroundings is ____ A. zero B. high C. low D. none of the mentioned

Last Answer : ANSWER : A

During sensible cooling of air, its wet bulb temperature (A) Decreases but dew point remains constant (B) Increases but dew point remains constant (C) Increases & the dew point decreases (D) Decreases & the dew point increases

Description : During sensible cooling of air, its wet bulb temperature (A) Decreases but dew point remains constant (B) Increases but dew point remains constant (C) Increases & the dew point decreases (D) Decreases & the dew point increases

Last Answer : (B) Increases but dew point remains constant

The cooling tower uses the phenomenon of evaporative cooling to cool warm water above the dbt of air. A. true B. false

Description : The cooling tower uses the phenomenon of evaporative cooling to cool warm water above the dbt of air. A. true B. false

Last Answer : ANSWER : B

Cooling and dehumidification of air is done in summer air conditioning. A. true B. false

Description : Cooling and dehumidification of air is done in summer air conditioning. A. true B. false

Last Answer : ANSWER : A

Which one of the following methods can be adopted to obtain isothermal compression in an air compressor? A. Increasing the weight of the compressor B. Inter-stage heating C. Atmospheric cooling D. Providing appropriate dimensions to the cylinder

Description : Which one of the following methods can be adopted to obtain isothermal compression in an air compressor? A. Increasing the weight of the compressor B. Inter-stage heating C. Atmospheric cooling D. Providing appropriate dimensions to the cylinder

Last Answer : ANSWER : A

Supercharging is the process of a. supplying the engine with air at a density greater than the density of the surrounding atmosphere b. providing forced cooling air c. injecting excess fuel d. raising the exhaust pressure

Description : Supercharging is the process of a. supplying the engine with air at a density greater than the density of the surrounding atmosphere b. providing forced cooling air c. injecting excess fuel d. raising the exhaust pressure

Last Answer : ANSWER a. supplying the engine with air at a density greater than the density of the surrounding atmosphere

Scavenging air in diesel engine means a. air used for combustion under pressure b. forced air for cooling the cylinder c. burnt air containing products of combustion d. air used for forcing burnt gases out of the engines cylinder during the exhaust stroke

Description : Scavenging air in diesel engine means a. air used for combustion under pressure b. forced air for cooling the cylinder c. burnt air containing products of combustion d. air used for forcing burnt gases out of the engines cylinder during the exhaust stroke

Last Answer : ANSWER d. air used for forcing burnt gases out of the engines cylinder during the exhaust stroke

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

Normally, an engine is warmed up at a. Full-speed with load. b. Full-speed without load. c. Reduced speed with load. d. Reduced speed without load.

Description : Normally, an engine is warmed up at a. Full-speed with load. b. Full-speed without load. c. Reduced speed with load. d. Reduced speed without load.

Last Answer : ANSWER b. full-speed without load

During sensible cooling process (A) Relative humidity decreases (B) Relative humidity increases (C) Wet bulb temperature decreases (D) Both (B) and (C)

Description : During sensible cooling process (A) Relative humidity decreases (B) Relative humidity increases (C) Wet bulb temperature decreases (D) Both (B) and (C)

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

In four stroke engine which of the following is also known as power stroke a. Suction stroke b. Compression stroke c. Expansion stroke d. Exhaust stroke (Ans:c) Measurements of fuel and air consumption, brake power and incylinder pressure. Tutorials on engine performance parameters. Heat balance sheet. Engine performance curves. 1. The increase in intake air temperature into IC engine,___________its efficiency A. increase B. decrease C. does not alter D. unpredictable on

Description : In four stroke engine which of the following is also known as power stroke a. Suction stroke b. Compression stroke c. Expansion stroke d. Exhaust stroke (Ans:c) Measurements of fuel and air ... into IC engine,___________its efficiency A. increase B. decrease C. does not alter D. unpredictable on

Last Answer : ANSWER : B

A diesel engine is usually more efficient than a spark ignition engine because a. Diesel being a heavier hydrocarbon, release more heat per kg than gasoline b. The air standard efficiency of diesel cycle is higher than the Otto cycle, at a fixed compression ratio c. The compression ratio of a diesel engine is higher than that of an Spark ignition engine d.Self ignition temperature of diesel is higher than that of gasoline.

Description : A diesel engine is usually more efficient than a spark ignition engine because a. Diesel being a heavier hydrocarbon, release more heat per kg than gasoline b. The air standard efficiency of diesel ... an Spark ignition engine d.Self ignition temperature of diesel is higher than that of gasoline.

Last Answer : ANSWER c. The compression ratio of a diesel engine is higher than that of an S.I engine

Cooling towers are rated in terms of A. approach B. range C. both of the mentioned D. none of the mentioned

Description : Cooling towers are rated in terms of A. approach B. range C. both of the mentioned D. none of the mentioned

Last Answer : ANSWER :C

The knocking in spark ignition engines can be reduced by a. Retarding the spark. b. Increasing the engine speed. c. Both a and b d. None of these.

Description : The knocking in spark ignition engines can be reduced by a. Retarding the spark. b. Increasing the engine speed. c. Both a and b d. None of these.

Last Answer : ANSWER c. Both a and b.

The knocking in spark ignition engines can be reduced by a. Retarding the spark. b. Increasing the engine speed. c. Both a and b. d. None of these.

Description : The knocking in spark ignition engines can be reduced by a. Retarding the spark. b. Increasing the engine speed. c. Both a and b. d. None of these.

Last Answer : ANSWER c. Both a and b

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

Presence of moisture in a refrigerant affects the working of (a) compressor (b) condenser (c) evaparator (d) expansion valve.

Description : Presence of moisture in a refrigerant affects the working of (a) compressor (b) condenser (c) evaparator (d) expansion valve.

Last Answer : Ans: a

Cooling water is required for following equipment in ammonia absorption plant (a) condenser (b) evaporator (c) condenser and absorber (d) condenser, absorber and separator (rectifier).

Description : Cooling water is required for following equipment in ammonia absorption plant (a) condenser (b) evaporator (c) condenser and absorber (d) condenser, absorber and separator (rectifier).

Last Answer : Ans: d

Under-cooling in a refrigeration cycle (a) increases COP (b) decreases COF (c) COP remains unaltered (d) other factors decide COP

Description : Under-cooling in a refrigeration cycle (a) increases COP (b) decreases COF (c) COP remains unaltered (d) other factors decide COP

Last Answer : Ans: a

One ton of the refrigeration is (a) the standard unit used in refrigeration problems (b) the cooling effect produced by melting 1 ton of ice (c) the refrigeration effect to freeze 1 ton of water at 0°C into ice at 0°C in 24 hours (d) the refrigeration effect to produce 1 ton of ice at NTP conditions

Description : One ton of the refrigeration is (a) the standard unit used in refrigeration problems (b) the cooling effect produced by melting 1 ton of ice (c) the refrigeration effect to freeze 1 ton of water at ... ice at 0°C in 24 hours (d) the refrigeration effect to produce 1 ton of ice at NTP conditions

Last Answer : Ans: c

The bank of tubes at the back of domestic refrigerator are (a) condenser tubes (b) evaporator tubes (c) refrigerant cooling tubes (d) capillary tubes

Description : The bank of tubes at the back of domestic refrigerator are (a) condenser tubes (b) evaporator tubes (c) refrigerant cooling tubes (d) capillary tubes

Last Answer : Ans: a

In multi stage compressor, the isothermal compression is achieved by A. Employing intercooler B. By constantly cooling the cylinder C. By running compressor at very slow speed D. By insulating the cylinder

Description : In multi stage compressor, the isothermal compression is achieved by A. Employing intercooler B. By constantly cooling the cylinder C. By running compressor at very slow speed D. By insulating the cylinder

Last Answer : ANSWER : C

Differentiate induced draft and forced draft cooling towers based on (i) Location of fan (ii) Corrosion of blades (iii) Efficiency (iv) Fan size

Description : Differentiate induced draft and forced draft cooling towers based on (i) Location of fan (ii) Corrosion of blades (iii) Efficiency (iv) Fan size

Last Answer : Differentiate induced draft and forced draft cooling towers based on (i) Location of fan (ii) Corrosion of blades (iii) Efficiency (iv) Fan size

Describe with neat sketch working of natural draft cooling towers.

Description : Describe with neat sketch working of natural draft cooling towers.

Last Answer : Natural draft cooling tower: -In natural draught cooling tower, the circulation of air is produced by the pressure difference of air inside the tower and outside atmospheric air Hot cooling water falls down ... the pressure difference of air inside and outside of cooling tower (natural flow).

State two factors on which efficiency of cooling tower depends.

Description : State two factors on which efficiency of cooling tower depends.

Last Answer : Efficiency of cooling tower depends on 1.Losses in duct, piping and joints, pipes should be free from scale/rust 2.Efficient heat transfer, maintenance of piping , Ensure fill is clean and free of debris. 3.Sufficient airflow and correct fan speed. 

Dew point temperature always gives an indication of the __________ of the moist air. (A) Dryness (B) Moisture content (C) Coolness (D) Latent heat

Description : Dew point temperature always gives an indication of the __________ of the moist air. (A) Dryness (B) Moisture content (C) Coolness (D) Latent heat

Last Answer : (B) Moisture content