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 : 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 : The specific volume on a psychrometric chart: a. Is plotted on vertical lines and read on the horizontal scale at the bottom of the chart b. Is plotted on horizontal lines and read on the vertical ... chart e. Is plotted on vertical lines and read on the horizontal scale at the top of the chart
Last Answer : Answer: D
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 : The dry-bulb temperature scale is read on a psychrometric chart along the: a. Left vertical axis b. Right vertical axis c. Saturation line and sloping downward to the right d. Top horizontal axis e. Horizontal axis on the bottom of the chart
Last Answer : ANSWER : E
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 psychrometric chart, specific humidity lines are: A. vertical B. horizontal C. inclined D. curved lines
Last Answer : ANSWER : 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 : On psychrometric chart, wet bulb temperature lines are A. horizontal with uniformly spaced B. horizontal with non-uniformly spaced C. inclined with uniformly spaced D. inclined with non-uniformly spaced
Last Answer : ANSWER :C
Description : In sensible heating or cooling, A. work done remains constant B. dry bulb temperature or air remains constant C. both of the mentioned D. none of the mentioned
Description : Cooling and dehumidification of air is done in summer air conditioning. A. true B. false
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 : Heating and humidification is done in A. summer air conditioning B. winter air conditioning C. both of the mentioned D. none of the mentioned
Description : What is sensible cooling of air? A. the cooling in which sensible heat of air is removed in order to reduce temperature B. the cooling in which temperature of air is reduced without changing in its moisture content C. both a. and b. D. none of the above
Description : Evaporative cooling process employs a combination of cooling and humidification in which the (A) Sensible heat is added (B) Sensible heat is removed and the latent heat is added (C) Latent heat is removed (D) Sensible heat is added and latent heat is removed
Last Answer : Option B
Description : Choose the correct statement (a) A refrigerant should have low latent heat (b) If operating temperature of system is low, then refrigerant with low boiling point should be used (c) Pre-cooling and sub-cooling bf refrigerant are same (d) Superheat and sensible heat of a. refrigerant are same
Last Answer : Ans: b
Description : In sensible cooling process the relative humidity: A. decreases B. increases C. remains constant 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 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 : 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 : 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 processes is followed by unsaturated air (with dry bulb temperature 12°C and relative humidity 47%) passing through water spray washer (temperature of water being constant at 40°C ... (B) Heating only (C) Both heating and humidification (D) Evaporative cooling
Last Answer : (C) Both heating and humidification
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
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 : Which one of the following methods can be adopted to obtain isothermal compression in an air compressor? A. Increasing the weight of the compressor B. Inter-stage heating C. Atmospheric cooling D. Providing appropriate dimensions to the cylinder
Description : Short horizontal lines on pressure-enthalpy chart show (a) constant pressure lines (b) constant temperature lines (c) constant total heat lines (d) constant entropy lines
Last Answer : Ans: a
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
Description : The refrigerant for a refrigerator should have (a) high sensible heat (b) high total heat (c) high latent heat (d) low latent heat
Last Answer : Ans: c
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 : The cooling tower uses the phenomenon of evaporative cooling to cool warm water above the dbt of air. A. true B. false
Description : In SI engines knocking can be reduced by (a) Increasing the compression ratio (b) Increasing the cooling water temperature (c) Retarding the spark advance (d) Increasing the inlet air temperature
Last Answer : Ans :c
Description : Supercharging is the process of a. supplying the engine with air at a density greater than the density of the surrounding atmosphere b. providing forced cooling air c. injecting excess fuel d. raising the exhaust pressure
Last Answer : ANSWER a. supplying the engine with air at a density greater than the density of the surrounding atmosphere
Description : Scavenging air in diesel engine means a. air used for combustion under pressure b. forced air for cooling the cylinder c. burnt air containing products of combustion d. air used for forcing burnt gases out of the engines cylinder during the exhaust stroke
Last Answer : ANSWER d. air used for forcing burnt gases out of the engines cylinder during the exhaust stroke
Description : Describe any two sources of air leak in surface condenser. Also describe effect of air leak on latent heat of steam and cooling water requirements.
Last Answer : ✓ The main sources of air leakage found in condenser are given below: 1) There is leakage of air from atmosphere at the joint of the parts which are internally under a pressure less ... hence evaporation enthalpy of steam increases therefore more amount of cooling water required in the condenser.
Description : On the pressure-enthalpy diagram, condensation and de-superheating is represented by a horizontal line because theprocess (a) takes place at constant pressure (b) takes place at constant temperature (c) takes place at constant entropy (d) takes place at constant enthalpy
Description : Air at dry bulb temperature Td1 is passed through the heating coil and some amount of air is by passed unaffected and leaves with dry bulb temperature Tb2 and the temperature of heated air is Td3 (where Td2 < Td3), what is the ... - Td1) / (Td2 - Td3) D. Bypass Factor = (Td2 - Td3) / (Td2 - Td1)
Description : The output of a diesel engine can be increased without increasing the engine speed or size in the following way A. feeding more fuel B. increasing the flywheel size C. heating intake air D. supercharging
Description : The heating value per unit volume of hydrogen gas is less than ______________ that of air. a) 1/12th b) 1/10th c) 2/3rd d) 1/3rd
Last Answer : Answer: d Explanation: None
Description : In a refrigeration cycle, the super heating……..C.O.P (a)decreases (b)does not change (c) increases (d)none of the above
Description : Vertical lines on pressure-enthalpy chart show constant (a) pressure lines (b) temperature lines (c) total heat lines (d) entropy lines
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
Description : State two factors on which efficiency of cooling tower depends.
Last Answer : Efficiency of cooling tower depends on 1.Losses in duct, piping and joints, pipes should be free from scale/rust 2.Efficient heat transfer, maintenance of piping , Ensure fill is clean and free of debris. 3.Sufficient airflow and correct fan speed.
Description : The equipment frequently used for adiabatic humidification-cooling operation with recirculating liquid is (A) Natural draft cooling tower (B) Induced draft cooling tower (C) Spray chamber (D) None of these
Last Answer : (C) Spray chamber
Description : In a cooling tower, water becomes cool by (A) Loosing sensible heat (B) Heat transfer to surroundings (C) Vaporisation due to heat loss to air (D) Loosing latent heat
Last Answer : (A) Loosing sensible heat
Description : During sensible cooling of air, its wet bulb temperature (A) Decreases but dew point remains constant (B) Increases but dew point remains constant (C) Increases & the dew point decreases (D) Decreases & the dew point increases
Last Answer : (B) Increases but dew point remains constant
Description : Steam produced in a boiler can be used for a variety of purposes including space heating, drying and _________________ a. Sterilization b. Humidification c. Power generation d. All of above
Last Answer : d. All of above
Description : The formation of frost on cooling coils in a refrigerator (a) increases heat transfer (b) improves C.O.P. of the system (c) increases power consumption (d) reduces power consumption
Description : Cooling water is required for following equipment in ammonia absorption plant (a) condenser (b) evaporator (c) condenser and absorber (d) condenser, absorber and separator (rectifier).
Last Answer : Ans: d
Description : Under-cooling in a refrigeration cycle (a) increases COP (b) decreases COF (c) COP remains unaltered (d) other factors decide COP
Description : One ton of the refrigeration is (a) the standard unit used in refrigeration problems (b) the cooling effect produced by melting 1 ton of ice (c) the refrigeration effect to freeze 1 ton of water at ... ice at 0°C in 24 hours (d) the refrigeration effect to produce 1 ton of ice at NTP conditions