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 : 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 : 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 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 : 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 : 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
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 : 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 : 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
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 : 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 : 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 : 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 : 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 : In sensible cooling process the relative humidity: A. decreases B. increases C. remains constant D. none of the above
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
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 : 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 : 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 : 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 : On a day when the partial pressure of water vapor remains constant, what happens as the temperature rises? a. the relative humidity increases b. the relative humidity decreases c. the relative humidity remains constant d. the air would eventually become saturated
Last Answer : the relative humidity decreases
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 : 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 : The temperature of air recorded by thermometer when the bulb is covered by a cotton wick saturated by water is called as A. dry bulb temperature B. wet bulb temperature C. stream temperature D. psychrometric temperature
Description : What is the specific humidity? A. the ratio of the mass of water vapour to the mass of the total mixture of air and water vapour B. the ratio of the mass of dry air to the mass of the total mixture ... ratio of the mass of water vapour to the mass of dry air in a mixture of air and water vapour
Description : The heat content of air is called the _____ of the air. a. Temperature b. Humidity c. Enthalpy d. Psychrometry e. Entropy
Description : When the humidity ratio of air increases the air is said to be A. dehumidified B. humidified C. heated D. cooled
Description : When humidity ratio of air ____ air is said to be dehumidified. A. increases B. decreases C. remains constant D. none of the mentioned
Description : Volumetric efficiency of air compressor is of the order of A. 20% to 30 % B. 40% to 50% C. 60% to 70% D. 70% to 90%
Description : Pick up the correct statement from the following: (A) Absolute humidity at a given temperature is equal to weight of moisture present in a unit volume (B) Relative humidity is the ratio of ... of vapours which could be contained at the same temperature when fully saturated (D) All the above
Last Answer : Answer: Option D
Description : The ratio of indicated thermal efficiency to the corresponding air standard cycle efficiency is called a. net efficiency b. efficiency ratio c. relative efficiency d. overall efficiency
Last Answer : ANSWER c. relative efficiency
Description : Pick up the incorrect statement from the following. For performing compressive strength test of cement (A) Cement and standard sand mortar are used in the ratio of 1 : 3 (B) Water is added at the ... cm 10 cm is used (D) The prepared moulds are kept in a atmosphere of 50% relative humidity
Last Answer : Answer: Option A
Description : The curing method is said to be good, when the relative humidity is kept [ A ] Greater than 80% [ B ] Less than 50% [ C ] 50% - 80% [ D ] None of the above
Last Answer : [ A ] Greater than 80%
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 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 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 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 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
Description : Paraffins have molecular structure of a) chain saturated b) chain unsaturated c) ring saturated d) ring unsaturated
Last Answer : Answer: a Explanation: None.
Description : In a constant pressure process steam is generated from 10 bar and 0.8 dry condition till it become dry and saturated. Determine amount of heat added per kg of steam. From steam table at 10 bar Tsat = 179.9°C hf = 762.6 kl/kg, hg = 2776.2 kJ/kg
Last Answer : Constant pressure process Final condition of steam is dry saturated Enthalpy of dry steam = hg= hf + hfg =2776.2 KJ/Kg .Given Latent heat of vaporization = hfg = hg - hf =2776.2-762.6 =2013.6 KJ/Kg Initial condition ... hfg = 762.6+0.8 X 2013.6 =2373.48 KJ/Kg Heat added = hg-hw = 402.72 KJ/kg
Description : Represent generation of steam on H-S diagram. Show constant dryness fraction lines, constant temperature lines, saturated line and superheated region on the same.
Last Answer : Represent generation of steam on H-S diagram. Show constant dryness fraction lines, constant temperature lines, saturated line and superheated region on the same.
Description : In psychrometric chart, specific humidity lines are: A. vertical B. horizontal C. inclined D. curved lines
Description : The specific humidity scale on a psychrometric chart is along the: a. Bottom horizontal axis b. Right side vertical axis c. Top horizontal axis at the top of the chart d. Left saturation line e. Left-side vertical axis and left side
Last Answer : Answer: B
Description : Accumulators should have adequate volume to store refrigerant charge at least (a) 10% (b) 25% (c) 50% (d) 75%
Last Answer : Ans: c