What is the perfect condition for dehumidification of air? A. air is heated above its dew point temperature B. air is cooled up to its dew point temperature C. air is heated below its dew point temperature D. air is cooled below its dew point temperature  

1 Answer

Answer :

ANSWER  : D

Related questions

Description : The temperature at which the air cannot hold all the water vapour mixed in it and some vapour starts condensing is called as A. humidification temperature B. dehumidification temperature C. dew point temperature D. none of the above

Last Answer : ANSWER : C

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

Description : When the humidity ratio of air increases the air is said to be A. dehumidified B. humidified C. heated D. cooled

Last Answer : ANSWER : B

Description : The power required to drive a turbo compressor for a given pressure ratio decreases when A. Air is heated at entry B. Air is cooled at entry C. Air is cooled at exit D. Air is heated at exit

Last Answer : ANSWER : B

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

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

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

Last Answer : ANSWER : A

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

Description : Dry-bulb temperature is: a. The absolute temperature corresponding to the atmospheric pressure b. The same as the wet-bulb temperature if the relative humidity is less than 100% c. Not required ... d. The temperature of the air measured with an ordinary thermometer e. The dew point temperature

Last Answer : Answer: D

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

Description : The dew point temperature is less than the wet bulb temperature for A. saturated air B. unsaturated air C. both saturated and unsaturated air D. none of the above

Last Answer : ANSWER : B

Description : When the dew point temperature is equal to the air temperature then the relative humidity is A. 0% B. 50% C. 100% D. unpredictable

Last Answer : ANSWER : C

Description : A Mixture of dry air and water,the formation of fog starts when, A. air temperature is equal to the dew point temperature B. air temperature is greater than the dew point temperature C. both a. and b. D. none of the above

Last Answer : ANSWER : A

Description : What is the temperature at which the water vapour in the mixture of water vapour in air, starts condensing called? A. condensation temperature B. dew point temperature C. vaporization temperature D. all of the above

Last Answer : ANSWER : B

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

Description : In chemical dehumidification process (A) Wet bulb temperature increases (B) Dry bulb temperature remains constant (C) Dew point temperature increases (D) Dry bulb temperature increases

Last Answer : Option B

Description : In psychrometric chart, dew point temperature lines are A. horizontal B. vertical C. curved D. straight lines slopping downwards to the right

Last Answer : ANSWER : A

Description : At 100% relative humidity, the wet bulb temperature is A. lower than the dew point temperature B. higher than the dew point temperature C. equal to the dew point temperature D. none of the above

Last Answer : ANSWER : C

Description : Air initially at 101. 3 kPa and 40°C and with a relative humidity of 50%, is cooled at constant pressure to 30°C. The cooled air has a (A) Higher dew point (B) Higher absolute (specific) humidity (C) Higher relative humidity (D) Higher wet bulb temperature

Last Answer : (C) Higher relative humidity

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

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

Description : Moist air is cooled along the line of constant __________ , when it is passed over a cold & dry cooling coil, such that no condensation occurs? (A) Enthalpy (B) Relative humidity (C) Wet bulb temperature (D) Dew point temperature

Last Answer : (D) Dew point temperature

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

Description : _________ is the temperature to which the air must be cooled, at constant pressure, to produce saturation.  a. relative humidity  b. triple point temperature  c. dew point  d. critical point

Last Answer : dew point

Description : A device for measuring relative humidity is called: a. A dew point analyzer b. An R. H. gauge c. An aspirating gauge d. A psychrometer e. A chronometer

Last Answer : Answer: D

Description : Air can be cooled and dehumidified by A. circulating chilled water in tube across air flow B. placing evaporator coil across air flow C. spraying chilled water to air D. all of the mentioned

Last Answer : ANSWER : D

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

Description : What has to happen for Condensation to occur in nature air must be cooled to its dew point and there must be some kind of solid surface present true or false?

Last Answer : 1

Description : __________ is the temperature at which a gas-vapor mixture becomes saturated, when cooled at constant total pressure out of contact with a liquid. (A) Dew point (B) Bubble point (C) Dry bulb temperature (D) Wet bulb temperature

Last Answer : (A) Dew point

Description : The temperature to which a vapour gas mixture must be cooled (at varying humidity) to become saturated is called the __________ temperature. (A) Dew point (B) Wet bulb (C) Dry bulb (D) None of these

Last Answer : (D) None of these

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

Description : Air standard cycle uses ____ as a working medium. a. Perfect gas b. Real gas c. Ideal gas d. Natural gas

Last Answer : ANSWER a. Perfect gas

Description : Air at a particular humidity is heated in a furnace. The new dew point (A) Decreases (B) Increases (C) Depends on the extent of heating (D) Remain unchanged

Last Answer : (B) Increases

Description : An ideal gas is heated at constant volume and then expanded isothermally. Show processes on P-V & T-S diagrams.

Last Answer : Process 1-2 : Constant volume process Process 2-3 : Constant temperature process (Isothermal process)

Description : For perfect gas a. cp – cv = R b. cp + cv = R c. cp / cv = R d. cp X cv = R Where cp & cv are specific heats at constant pressure and volume.

Last Answer : ANSWER a. CP – CV = R

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

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

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

Description : . In chemical dehumidification of air (A) Both specific humidity & dry bulb temperature increases (B) Both specific humidity & dry bulb temperature decreases (C) Specific humidity decreases & dry bulb temperature increases (D) Specific humidity increases & dry bulb temperature decreases

Last Answer : (C) Specific humidity decreases & dry bulb temperature increases

Description : What happen with the air in a soccer ball with a cooled and heated?

Last Answer : The air pressure goes down when cooled, goes up when heated. Asoccer ball left outdoors in freezing weather does not have muchbounce. Left outside on a hot day, has a lot of bounce.

Description : What happen with the air in a soccer ball with a cooled and heated?

Last Answer : The air pressure goes down when cooled, goes up when heated. Asoccer ball left outdoors in freezing weather does not have muchbounce. Left outside on a hot day, has a lot of bounce.

Description : Which of the following statements concerning the specific gravity of a battery electrolyte is true? A. The electrolyte becomes less dense when it is cooled. B. The specific gravity reading is lowered ... water is added. D. The temperature does not affect the specific gravity of the electrolyte.

Last Answer : Answer: B

Description : . The most suitable equipment for removing the fine dust particle (< 1 micron dia.) from air below its dew point will be a/an (A) Bag filter (B) Electrostatic precipitator (C) Cyclone separator (D) Wet scrubber

Last Answer : (B) Electrostatic precipitator

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

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

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

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

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

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