Description : When the rate of evaporation of water is zero, the relative humidity of the air is A. 0% B. 100% C. 50% D. unpredictable
Last Answer : ANSWER : B
Description : If atmospheric temperature and dew point are nearly equal, then the relative humidity is (A) Zero (B) 50% (C) Almost 100% (D) unpredictable
Last Answer : (C) Almost 100%
Description : What is the relative humidity for a saturated air? A. 0% B. 50% C. 100% D. cannot say
Last Answer : ANSWER : C
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
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 : 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
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
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
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 : When dew point la reached it is said that at that temperature (a) the atmosphere is said to be saturated with water vapour (b) the relative humidity of the atmosphere is 100% (c) the atmosphere can hold no more water vapour (d) All the above
Last Answer : Ans: (a)
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
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
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
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
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
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 : Which of the following can be calculated theoretically using steam table and Dalton's law of partial pressure; if the relative humidity and dry bulb temperature of moist air is known? (A) Dew point (B) Humidity ratio (C) Wet bulb temperature (D) None of these
Last Answer : (C) Wet bulb temperature
Description : During sensible heating of humid air (A) Relative humidity increases (B) Dew point remains constant (C) Dry bulb & wet bulb temperature increases (D) Both 'b' & 'c'
Last Answer : (D) Both 'b' & 'c'
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 : _________ 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 : Water will not be vaporized if – (1) the temperature is 0°C (2) the humidity is 0% (3) the humidity is 100% (4) the temperature is 100°C
Last Answer : (3) the humidity is 100% Explanation: If the relative humidity is 100 percent, water will not evaporate as the air is already saturated with moisture. When relative humidity approaches 100 percent, condensation can occur. The lower the relative humidity, the easier it is for moisture to evaporate.
Description : Water will not be vapourised if (1) the temperature is 0°C (2) the humidity is 0% (3) the humidity is 100% (4) the temperature is 100°C
Last Answer : the humidity is 100%
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 : 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
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
Description : 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
Last Answer : ANSWER : D
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
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
Description : Sling psychrometer is used to measure A. only dry bulb temperature B. only wet bulb temperature C. dry and wet bulb temperature 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
Description : What is the degree of saturation? A. the ratio of the actual relative humidity to the saturated specific humidity at the same temperature B. the ratio of the actual specific humidity to the ... specific humidity to the actual specific humidity at the same temperature D. none of the above
Description : Clearance volume in compressor should be A. As large as possible B. As small as possible C. About 50% of swept volume D. About 100% of swept volume
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
Description : If the intake air temperature of Internal combustion engine increases, its efficiency will a. increase b. decrease c.remains same d unpredictable
Last Answer : ANSWER b. decrease
Description : What is the dew-point when the dry bulb temperature is 20C and the relative humidity is 17?
Last Answer : at 17% relative humidity the dew point is -5.8C at a dry bulb of20C
Description : In psychrometric chart, dew point temperature lines are A. horizontal B. vertical C. curved D. straight lines slopping downwards to the right
Description : In amplitude modulation technique the unmodulated carrier is referred to as having ______. A. 100% modulation B. 0% modulation C. 50% modulated D. Over modulated
Last Answer : B. 0% modulation
Description : 4. A haemophilic man marries a normal homozygous woman. What is the probability that their son will be haemophilic a) 100% b) 75 % c) 50% d) 0%
Last Answer : d) 0%
Description : In sensible cooling process the relative humidity: A. decreases B. increases C. remains constant 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
Description : The fuel air ratio in a petrol engine fitted with suction carburetor, operating with dirty air filter as compared to clean filter will be A. higher B. lower C. remain unaffected D. unpredictable
Description : The air requirement of a petrol engine during starting compared to the theoretical air requirement for complete combustion is A. more B.unpredictable C. same D. less
Description : The area of actual indicator diagram on an air compressor as compared to area of ideal indicator diagram is A. Less B. More C. Same 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
Description : The capacity of the compressor will be highest when its intake temperature is A. Lowest B. highest C. Atmospheric D. Unpredictable
Description : The heat content of air is called the _____ of the air. a. Temperature b. Humidity c. Enthalpy d. Psychrometry e. Entropy
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
Description : Is define as the ratio of the actual pressure of the vapor a. Relative Humidity b. Humidity Ratio c. Dew Point d. Adiabatic Saturation
Last Answer : Relative Humidity
Description : With increase in absolute humidity, the dew point of an unsaturated mixture of air and water vapor (at constant pressure and temperature). (A) Increases (B) Remains unchanged (C) Decreases (D) Decreases linearly
Last Answer : (A) Increases