When the rate of evaporation of water is zero, the relative humidity of the air is A. 0% B. 100% C. 50% D. unpredictable  

1 Answer

Answer :

ANSWER  : B

Related questions

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 : What is the relative humidity for a saturated air? A. 0% B. 50% C. 100% D. cannot say

Last Answer : ANSWER : C

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 : 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

Last Answer : ANSWER : C

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 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

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

Last Answer : ANSWER : B

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 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 : 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

Last Answer : ANSWER : C

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

Last Answer : ANSWER : B

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

Last Answer : ANSWER : B

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 : 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

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

Last Answer : ANSWER : A

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

Last Answer : ANSWER : D

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

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

Last Answer : ANSWER : B

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 : 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 : 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 : 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 specific fuel consumption of a petrol engine compared to diesel engine of same H.P is A. same B.more C. less D. unpredictable

Last Answer : ANSWER : B

Description : The compressor performance at higher altitude compare to sea level will be A. Same B. Higher C. Lower D. Unpredictable

Last Answer : ANSWER : C

Description : The capacity of the compressor will be highest when its intake temperature is A. Lowest B. highest C. Atmospheric D. Unpredictable

Last Answer : ANSWER : C

Description : Compressor at high altitude will draw A. More power B. Less power C. Same power D. Unpredictable

Last Answer : ANSWER : B

Description : Volumetric efficiency of a compressor without clearance volume A. Increases with increase in compression ratio B. Decreases wit increase in compression ratio C. Not dependent upon compression ratio D. Unpredictable

Last Answer : ANSWER : C

Description : Thermal efficiency of an internal combustion engine on weak mixture is a. higher b. lower c. unaffected d. unpredictable

Last Answer : ANSWER a. higher

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

Last Answer : ANSWER : D

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 : 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

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 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 : When humidity ratio of air ____ air is said to be dehumidified. A. increases B. decreases C. remains constant D. none of the mentioned

Last Answer : ANSWER : B

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%

Last Answer : ANSWER : D

Description : India has eight coastal states but more than half the sea salt is made along the Gujarat coast because (a) Gandhiji started the salt movement in Gujarat (b) Low rainfall and relative humidity are ideal ... ) Kandla port exports salt (d) The salinity of sea water is very high near the Gujarat coast

Last Answer : Ans: (b)

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 : Reducing suction pressure in refrigeration cycle (a) lowers evaporation temperature (b) increases power required per ton of refrigeration (c) lowers compressor capacity because vapour is lighter (d) all of the above.

Last Answer : Ans: d

Description : The advantage of dry compression is that (a) it permits higher speeds to be used (b) it permits complete evaporation in the evaporator (c) it results in high volumetirc and mechanical efficiency (d) all of the above

Last Answer : Ans: d

Description : For proper refrigeration in a cabinet, if the temperature and vapour pressure difference between cabinet and atmosphereis high, then (a) bigger cabinet should be used (b) smaller cabinet should ... tight vapour seal should be used (d) refrigerant with lower evaporation temperature should be used

Last Answer : Ans: c

Description : The lower horizontal line of the refrigeration cycle plotted on pressure-enthalpy-diagram represents (a) condensation of the refrigerant vapour (b) evaporation of the refrigerant liquid (c) compression of the refrigerant vapour (d) metering of the refrigerant liquid

Last Answer : Ans: b

Description : The process of breaking up or liquid into fine droplets by spraying is A. vaporization B. atomization C. condensation D. evaporation

Last Answer : ANSWER : B

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 : During the constant rate period of drying of a solid, (A) Increased air humidity decreases the rate of drying (B) Increasing the air temperature decreases the drying rate (C) Surface evaporation of unbound moisture occurs (D) None of these

Last Answer : (C) Surface evaporation of unbound moisture occurs