For the air water system under ambient conditions, the adiabatic saturation temperature and the wet bulb temperature are nearly equal, because (A) Water has a high latent heat of evaporation (B) Lewis number is close to unity (C) They are always equal under all circumstances

For the air water system under ambient conditions, the adiabatic
saturation temperature and the wet bulb temperature are nearly equal,
because
(A) Water has a high latent heat of evaporation
(B) Lewis number is close to unity
(C) They are always equal under all circumstances
by

1 Answer

Answer :

(A) Water has a high latent heat of evaporation
by

Related questions

Pick out the wrong statement (A) A horizontal line on the humidity chart indicates the temperature changes at constant molal humidity (B) When water is cooled from 80 to 70°C by exposure to the air with a wet bulb temperature of 60°C, then both the approach & the range would be 10°C (C) For unsaturated air-water vapor mixture at atmospheric conditions, the wet bulb temperature & adiabatic cooling lines are the same (D) Relative saturation of unsaturated mixture of water vapor & air cannot be increased by either reducing the mixture temperature or by increasing the total pressure

Description : Pick out the wrong statement (A) A horizontal line on the humidity chart indicates the temperature changes at constant molal humidity (B) When water is cooled from 80 to 70°C by exposure ... & air cannot be increased by either reducing the mixture temperature or by increasing the total pressure

Last Answer : (D) Relative saturation of unsaturated mixture of water vapor & air cannot be increased by either reducing the mixture temperature or by increasing the total pressure

When the psychometric ratio is __________ then the adiabatic saturation temperature and wet bulb temperature becomes equal. (A) 1 (B) < 1 (C) > 1 (D) ∞

Description : When the psychometric ratio is __________ then the adiabatic saturation temperature and wet bulb temperature becomes equal. (A) 1 (B) < 1 (C) > 1 (D) ∞

Last Answer : (A) 1

__________ temperature remains constant during adiabatic saturation process of unsaturated air. (A) Dew point (B) Dry bulb (C) Wet bulb (D) None of these

Description : __________ temperature remains constant during adiabatic saturation process of unsaturated air. (A) Dew point (B) Dry bulb (C) Wet bulb (D) None of these

Last Answer : (C) Wet bulb

The difference of wet bulb temperature and adiabatic saturation temperature of unsaturated mixture of any system is (A) +ve (B) -ve (C) Zero (D) None of these

Description : The difference of wet bulb temperature and adiabatic saturation temperature of unsaturated mixture of any system is (A) +ve (B) -ve (C) Zero (D) None of these

Last Answer : (A) +ve

Steady state temperature reached by a small amount of liquid evaporating into a large amount of unsaturated vapour-gas mixture is called the __________ temperature. (A) Dry-bulb (B) Wet-bulb (C) Dew point (D) Adiabatic saturation

Description : Steady state temperature reached by a small amount of liquid evaporating into a large amount of unsaturated vapour-gas mixture is called the __________ temperature. (A) Dry-bulb (B) Wet-bulb (C) Dew point (D) Adiabatic saturation

Last Answer : (B) Wet-bulb

At 100% relative humidity, the dew point temperature of moist air is (A) Less than the wet bulb temperature (B) More than the wet bulb temperature (C) Equal to the wet bulb temperature (D) Equal to the ambient temperature

Description : At 100% relative humidity, the dew point temperature of moist air is (A) Less than the wet bulb temperature (B) More than the wet bulb temperature (C) Equal to the wet bulb temperature (D) Equal to the ambient temperature

Last Answer : (B) More than the wet bulb temperature

The cooling water reduces the water temperature close to _____. • Dry bulb temperature • Ambient wet bulb temperature • Dew point temperature • None of the above

Description : The cooling water reduces the water temperature close to _____. • Dry bulb temperature • Ambient wet bulb temperature • Dew point temperature • None of the above

Last Answer : Ambient wet bulb temperature

Minimum temperature upto which water can be theoretically cooled down in the cooling tower by evaporative cooling is equal to the __________ temperature of air. (A) Wet bulb (B) Dry bulb (C) Saturation (D) Dew point

Description : Minimum temperature upto which water can be theoretically cooled down in the cooling tower by evaporative cooling is equal to the __________ temperature of air. (A) Wet bulb (B) Dry bulb (C) Saturation (D) Dew point

Last Answer : Option A

At any point on the saturation curve in psychometric chart, the dry bulb temperature is always A. less than the corresponding wet bulb temperature B. more than the corresponding wet bulb temperature C. equal to the corresponding wet bulb temperature D. cannot predict

Description : At any point on the saturation curve in psychometric chart, the dry bulb temperature is always A. less than the corresponding wet bulb temperature B. more than the corresponding wet bulb temperature C. equal to the corresponding wet bulb temperature D. cannot predict

Last Answer : ANSWER : 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 minimum temperature to which the water can be cooled in a cooling tower is the __________ temperature of air. (A) Ambient (B) Dry bulb (C) Dew point (D) Wet bulb

Description : The minimum temperature to which the water can be cooled in a cooling tower is the __________ temperature of air. (A) Ambient (B) Dry bulb (C) Dew point (D) Wet bulb

Last Answer : C) Dew point

The dew point temperature lines on psychrometric charts are straight inclined sloping downwards to the right. When relative humidity of moist air is 100%, then (A) Wet bulb temperature=dry bulb temperature (B) Wet bulb temperature=dew point temperature (C) Saturation temperature=dew point temperature (D) All 'a', 'b' & 'c

Description : The dew point temperature lines on psychrometric charts are straight inclined sloping downwards to the right. When relative humidity of moist air is 100%, then (A) Wet bulb temperature=dry bulb temperature (B) ... temperature (C) Saturation temperature=dew point temperature (D) All 'a', 'b' & 'c

Last Answer : Option D

__________ remains constant during the adiabatic cooling of moist air. (A) Wet bulb temperature (B) Dry bulb temperature (C) Relative humidity (D) Specific humidity

Description : __________ remains constant during the adiabatic cooling of moist air. (A) Wet bulb temperature (B) Dry bulb temperature (C) Relative humidity (D) Specific humidity

Last Answer : Option A

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.

When the difference in the temperature of the wet-bulb thermometer and dry-bulb thermometer is large, what does it indicate about the air? w) it is very dry x) it is nearly saturated y) it is very warm z) it is very cold

Description : When the difference in the temperature of the wet-bulb thermometer and dry-bulb thermometer is large, what does it indicate about the air? w) it is very dry x) it is nearly saturated y) it is very warm z) it is very cold

Last Answer : ANSWER: W -- IT IS VERY DRY

The temperature of water cooled in cooling tower is always __________ temperature of entering air. (A) More than the wet bulb (B) Less than the wet bulb (C) Equal to the wet bulb (D) Equal to the dry bulb

Description : The temperature of water cooled in cooling tower is always __________ temperature of entering air. (A) More than the wet bulb (B) Less than the wet bulb (C) Equal to the wet bulb (D) Equal to the dry bulb

Last Answer : (A) More than the wet bulb

Only small amount of evaporation of water produces large cooling effects because of its (A) Large latent heat (B) Low viscosity (C) Small latent heat (D) None of these

Description : Only small amount of evaporation of water produces large cooling effects because of its (A) Large latent heat (B) Low viscosity (C) Small latent heat (D) None of these

Last Answer : (A) Large latent heat

Pick out the wrong statement. (A) The mass diffusivity, the thermal diffusivity and the eddy momentum diffusivity are the same for NSc = NPr= 1 (B) 1 Nm3 of dry air is lighter than 1Nm3 of humid air (C) The Lewis number of a mixture is unity, when the thermal diffusivity is equal to the mass diffusivity

Description : Pick out the wrong statement. (A) The mass diffusivity, the thermal diffusivity and the eddy momentum diffusivity are the same for NSc = NPr= 1 (B) 1 Nm3 of dry air is lighter ... ) The Lewis number of a mixture is unity, when the thermal diffusivity is equal to the mass diffusivity

Last Answer : (B) 1 Nm3 of dry air is lighter than 1Nm3 of humid air

Wet bulb and dry bulb temperatures becomes identical at __________ percent saturation curve. (A) 100 (B) 50 (C) 78 (D) None of these

Description : Wet bulb and dry bulb temperatures becomes identical at __________ percent saturation curve. (A) 100 (B) 50 (C) 78 (D) None of these

Last Answer : (A) 100

Heat sensitive materials with very high latent heat of vaporisation may be economically separated using (A) Liquid extraction (B) Distillation (C) Evaporation (D) Absorption

Description : Heat sensitive materials with very high latent heat of vaporisation may be economically separated using (A) Liquid extraction (B) Distillation (C) Evaporation (D) Absorption

Last Answer : (A) Liquid extraction

___________________ is a vapor at the saturation conditions (saturation temperature and saturation pressure).  a) Vapor  b) Saturated Vapor  c) Superheated Vapor  d) Wet Vapor

Description : ___________________ is a vapor at the saturation conditions (saturation temperature and saturation pressure).  a) Vapor  b) Saturated Vapor  c) Superheated Vapor  d) Wet Vapor

Last Answer : Saturated Vapor

Actual flame temperature is always lower than the adiabatic flame temperature, because there is (A) No possibility of obtaining complete combustion at high temperature (B) Always loss of heat from the flame (C) Both (A) and (B) (D) Neither (A) nor (B)

Description : Actual flame temperature is always lower than the adiabatic flame temperature, because there is (A) No possibility of obtaining complete combustion at high temperature (B) Always loss of heat from the flame (C) Both (A) and (B) (D) Neither (A) nor (B)

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

The dew point of moist air becomes __________ with decrease in its relative humidity. (A) Less than the wet bulb temperature (B) More than the wet bulb temperature (C) More than the dry bulb temperature (D) Equal to wet bulb temperature

Description : The dew point of moist air becomes __________ with decrease in its relative humidity. (A) Less than the wet bulb temperature (B) More than the wet bulb temperature (C) More than the dry bulb temperature (D) Equal to wet bulb temperature

Last Answer : Option A

Wet-bulb temperature is: a. The temperature indicated by a thermometer whose bulb covered by a water-wetted wick and exposed to a rapidly moving stream of air b. The same as the dry-bulb temperature if the relative humidity is less than 100% c. The dew point temperature d. Always less than the dry-bulb temperature e. Not required to find the relative humidity

Description : Wet-bulb temperature is: a. The temperature indicated by a thermometer whose bulb covered by a water-wetted wick and exposed to a rapidly moving stream of air b. The same as the dry-bulb ... point temperature d. Always less than the dry-bulb temperature e. Not required to find the relative humidity

Last Answer : Answer: A

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

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

The ambient air is stable when the ambient lapse rate is – (1) Neutrally stable (2) Hyper-adiabatic (3) Sub-adiabatic (4) Super-adiabatic

Description : The ambient air is stable when the ambient lapse rate is – (1) Neutrally stable (2) Hyper-adiabatic (3) Sub-adiabatic (4) Super-adiabatic

Last Answer : (3) Sub-adiabatic

The ambient air is stable when the ambient lapse rate is (1) Neutrally stable (2) Hyper-adiabatic (3) Sub-adiabatic (4) Super-adiabatic

Description : The ambient air is stable when the ambient lapse rate is (1) Neutrally stable (2) Hyper-adiabatic (3) Sub-adiabatic (4) Super-adiabatic

Last Answer :  Sub-adiabatic

The McCabe ΔL law states that the (A) Molar heats of vaporisation of components are nearly equal (B) Linear crystal growth rate depends on the degree of super-saturation (C) Linear crystal growth rate does not depend on the crystal size (D) Linear crystal growth rate depends on the crystal size

Description : The McCabe ΔL law states that the (A) Molar heats of vaporisation of components are nearly equal (B) Linear crystal growth rate depends on the degree of super-saturation (C) Linear ... does not depend on the crystal size (D) Linear crystal growth rate depends on the crystal size

Last Answer : (C) Linear crystal growth rate does not depend on the crystal size

Is a steady flow process at total constant pressure through a control volume for which there is no heat?  a. Adiabatic Saturation Process  b. Dew point  c. Adiabatic Ratio  d. None of the above

Description : Is a steady flow process at total constant pressure through a control volume for which there is no heat?  a. Adiabatic Saturation Process  b. Dew point  c. Adiabatic Ratio  d. None of the above

Last Answer : Adiabatic Saturation Process

Relative humidity is a) the ratio of water vapour in the air compared to the total amount water vapour the air could contain at a given temperature b) equal to the dry bulb temperature divided by the wet bulb temperature c) equal to the wet bulb temperature divided by the dry bulb temperature d) the ratio of the mass of water vapour divided by the mass of dry air e) the ratio of the mass of water vapour divided by the mass of wet air

Description : Relative humidity is a) the ratio of water vapour in the air compared to the total amount water vapour the air could contain at a given temperature b) equal to the dry bulb temperature divided by the wet bulb ... of dry air e) the ratio of the mass of water vapour divided by the mass of wet air

Last Answer : ANSWER : A

Under ideal conditions, the collector current is (a) Equal to base current (b) Nearly equal to emitter current (c) Less than base current (d) always zero

Description : Under ideal conditions, the collector current is (a) Equal to base current (b) Nearly equal to emitter current (c) Less than base current (d) always zero

Last Answer : (b) Nearly equal to emitter current

Can a cooling tower cool water below the wet bulb temperature of inlet air? (A) Yes (B) No (C) Yes; but height of cooling tower will be prohibitively high (D) Yes; but the air flow rate should be excessively high

Description : Can a cooling tower cool water below the wet bulb temperature of inlet air? (A) Yes (B) No (C) Yes; but height of cooling tower will be prohibitively high (D) Yes; but the air flow rate should be excessively high

Last Answer : (B) No

What is the latent heat of evaporation ?

Description : What is the latent heat of evaporation ?

Last Answer : : When heat is applied to a liquid, when the temperature rises to boiling point, no matter how much heat is applied, the temperature remains constant until it is completely converted into liquid vapor. The amount of heat that converts a liquid into a vapor state is the latent heat of evaporation.

Which of the following statement is true? A. the chart is plotted for pressure equal to 760mm Hg B. the constant wbt line represents adiabatic saturation process C. the constant wbt line coincides with constant enthalpy line D. all of the mentioned

Description : Which of the following statement is true? A. the chart is plotted for pressure equal to 760mm Hg B. the constant wbt line represents adiabatic saturation process C. the constant wbt line coincides with constant enthalpy line D. all of the mentioned

Last Answer : ANSWER : D

Removal of __________ heat is involved in the condensation of a vapor under saturated conditions. (A) Super (B) Sensible (C) Latent (D) Both (B) & (C)

Description : Removal of __________ heat is involved in the condensation of a vapor under saturated conditions. (A) Super (B) Sensible (C) Latent (D) Both (B) & (C)

Last Answer : (B) Sensible

Pick out the correct statement. (A) Fanning friction factor is inversely proportional to Reynolds number always (B) The property of a randomly packed bed (with raschig rings) is given by the ratio of the total volume to the volume of voids in the bed (C) Mach number in an incompressible fluid is always unity (D) Mach number is given by the ratio of the speed of the fluid to that of sound in the fluid under conditions of flow

Description : Pick out the correct statement. (A) Fanning friction factor is inversely proportional to Reynolds number always (B) The property of a randomly packed bed (with raschig rings) is given by the ratio of the ... the ratio of the speed of the fluid to that of sound in the fluid under conditions of flow

Last Answer : (D) Mach number is given by the ratio of the speed of the fluid to that of sound in the fluid under conditions of flow

Pick out the wrong statement. (A) Different solids have different equilibrium moisture curves (B) Total condenser or reboiler is considered equivalent to one theoretical plate in McCabe-Thiele method of theoretical plate calculation for distillation column (C) Heat removal load on cooler remains constant, even with increase of the reflux ratio in a distillation column (D) Even a forced draft cooling tower cannot cool water below the wet bulb temperature

Description : Pick out the wrong statement. (A) Different solids have different equilibrium moisture curves (B) Total condenser or reboiler is considered equivalent to one theoretical plate in McCabe-Thiele method of ... (D) Even a forced draft cooling tower cannot cool water below the wet bulb temperature

Last Answer : (C) Heat removal load on cooler remains constant, even with increase of the reflux ratio in a distillation column

Which of the following statement(s) is/are true concerning the pathophysiology of gas exchange? a. Hypoventilation in relation to perfusion can result in an oxygen saturation of less than 100% b. Diffusion block and / mismatch can almost completely be overcome by breathing 100% oxygen c. Transpulmonary shunting does not occur under normal circumstances d. The normal arterial oxygen saturation should be 100%

Description : Which of the following statement(s) is/are true concerning the pathophysiology of gas exchange? a. Hypoventilation in relation to perfusion can result in an oxygen saturation of less than 100% ... does not occur under normal circumstances d. The normal arterial oxygen saturation should be 100%

Last Answer : Answer: a, b Under normal conditions, red blood cells in the pulmonary capillaries become fully saturated and oxygen dissolves in plasma resulting in blood PO2 of 100 and O2 saturation of 100%. This ... the fact that normal arterial PO2 is 90-100 mm Hg and the normal O2 saturation is 98%

Dry bulb temperature of the gas is __________ the wet bulb temperature. (A) Less than (B) More than (C) Equal to (D) None of these

Description : Dry bulb temperature of the gas is __________ the wet bulb temperature. (A) Less than (B) More than (C) Equal to (D) None of these

Last Answer : (B) More than

The term "cooling range" in a cooling tower refers to the difference in the temperature of (A) Cold water leaving the tower and the wet bulb temperature of the surrounding air(B) Hot water entering the tower and the wet bulb temperature of thesurrounding air(C) Hot water entering the tower and the cooled water leaving the tower(D) None of these

Description : The term "cooling range" in a cooling tower refers to the difference in the temperature of (A) Cold water leaving the tower and the wet bulb temperature of the surrounding air (B) Hot water entering the ... air (C) Hot water entering the tower and the cooled water leaving the tower (D) None of these

Last Answer : (C) Hot water entering the tower and the cooled water leaving the tower

In a forced draft cooling tower, water is cooled from 95 to 80°F by exposure to air with a wet bulb temperature of 70°F. In this case, the (A) Range is 15°F (B) Approach is 10°F (C) Both (A) & (B) (D) Neither (A) nor (B)

Description : In a forced draft cooling tower, water is cooled from 95 to 80°F by exposure to air with a wet bulb temperature of 70°F. In this case, the (A) Range is 15°F (B) Approach is 10°F (C) Both (A) & (B) (D) Neither (A) nor (B)

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

Unsaturated air (with dry bulb and wet bulb temperatures being 45°C and 25°C respectively) is passed through a water spray chamber maintained at 23°C. The air will be cooled and (A) Humidified with wet bulb temperature decreasingB) Humidified at constant wet bulb temperature(C) Dehumidified(D) None of these

Description : Unsaturated air (with dry bulb and wet bulb temperatures being 45°C and 25°C respectively) is passed through a water spray chamber maintained at 23°C. The air will be cooled and (A) ... temperature decreasing B) Humidified at constant wet bulb temperature (C) Dehumidified (D) None of these

Last Answer : (A) Humidified with wet bulb temperature decreasing

The term "approach" in a cooling tower refers to the difference in the temperature of the (A) Cold water leaving the tower and the wet bulb temperature of the surrounding air (B) Hot water entering the tower and the wet bulb temperature of the surrounding air (C) Hot water entering and the cooled water leaving the cooling tower (D) None of these

Description : The term "approach" in a cooling tower refers to the difference in the temperature of the (A) Cold water leaving the tower and the wet bulb temperature of the surrounding air (B ... (C) Hot water entering and the cooled water leaving the cooling tower (D) None of these

Last Answer : (A) Cold water leaving the tower and the wet bulb temperature of the surrounding air

Unsaturated air (with dry bulb temperature and dew point being 35°C and 18°C respectively) is passed through a water spray chamber maintained at 15°C. The air will be cooled (A) And humidified (B) And dehumidified with increase in wet bulb temperature (C) At the same relative humidity (D) And dehumidified with decrease in wet bulb temperature

Description : Unsaturated air (with dry bulb temperature and dew point being 35°C and 18°C respectively) is passed through a water spray chamber maintained at 15°C. The air will be cooled (A) And ... (C) At the same relative humidity (D) And dehumidified with decrease in wet bulb temperature

Last Answer : (D) And dehumidified with decrease in wet bulb temperature

During dehumidification of unsaturated air wet bulb temperature & partial pressure of vapor are not constant. However, during evaporative cooling process with recirculated water supply, the __________ remains constant. (A) Wet bulb temperature (B) Partial pressure of water vapor (C) Relative humidity (D) None of these

Description : During dehumidification of unsaturated air wet bulb temperature & partial pressure of vapor are not constant. However, during evaporative cooling process with recirculated water supply, the __________ remains ... pressure of water vapor (C) Relative humidity (D) None of these

Last Answer : (A) Wet bulb temperature

Which of the following psychrometric processes is followed by water vapour laden unsaturated air, when it is passed through solid or liquid adsorbent? (A) Cooling and dehumidification (B) Heating and dehumidification at almost constant wet bulb temperature (C) Dehumidification with dry bulb temperature remaining constant (D) None of these

Description : Which of the following psychrometric processes is followed by water vapour laden unsaturated air, when it is passed through solid or liquid adsorbent? (A) Cooling and dehumidification ... (C) Dehumidification with dry bulb temperature remaining constant (D) None of these

Last Answer : (B) Heating and dehumidification at almost constant wet bulb temperature

When dry bulb temperature & wet bulb temperature of moist air is the same, it means that the (A) Partial pressure of water vapour is less than the total pressure (B) Humidity is < 100% & dew point temperature of air has not reached (C) Dew point temperature of air has not reached & air is not saturated fully (D) Air is fully saturated

Description : When dry bulb temperature & wet bulb temperature of moist air is the same, it means that the (A) Partial pressure of water vapour is less than the total pressure (B) Humidity is < 100% & dew ... Dew point temperature of air has not reached & air is not saturated fully (D) Air is fully saturated

Last Answer : (D) Air is fully saturated