Film boiling is usually not desired in commercial equipments, because (A) The heat transfer rate is low in view of the large temperature drop (B) It is difficult to maintain (C) It is not economic (D) None of these

Film boiling is usually not desired in commercial equipments, because

(A) The heat transfer rate is low in view of the large temperature drop

(B) It is difficult to maintain

(C) It is not economic

(D) None of these

by

1 Answer

Answer :

(A) The heat transfer rate is low in view of the large temperature drop


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Related questions

Condensing film co-efficient for steam on horizontal tubes ranges from 5000 to 15000 Kcal/hr.m2 .°C. Condensation of vapor is carried out inside the tube in a shell and tube heat exchanger, when the (A) Higher condensing film co-efficient is desired (B) Condensate is corrosive in nature (C) Lower pressure drop through the exchanger is desired (D) Temperature of the incoming vapor is very high Answer: Option B

Description : Condensing film co-efficient for steam on horizontal tubes ranges from 5000 to 15000 Kcal/hr.m2 .°C. Condensation of vapor is carried out inside the tube in a shell and tube heat ... drop through the exchanger is desired (D) Temperature of the incoming vapor is very high

Last Answer : (B) Supersaturated

Pick out the wrong statement. (A) Superheated steam is preferably not used for process heating because of its low heat transfer film co-efficient (B) In a shell and tube heat exchanger, the shell pressure drop is maximum for orifice baffles (C) S.I. unit of fouling factor is Watt/m2 .°K (D) Longitudinal fins are used in extended surface heat exchangers, when the direction of fluid flow is parallel to the axis of the tube

Description : Pick out the wrong statement. (A) Superheated steam is preferably not used for process heating because of its low heat transfer film co-efficient (B) In a shell and tube heat exchanger ... surface heat exchangers, when the direction of fluid flow is parallel to the axis of the tube

Last Answer : (C) S.I. unit of fouling factor is Watt/m2 .°K

Plate towers are preferred to packed towers, when large temperature changes are involved, because of the reason that the (A) Packing may be crushed due to thermal expansion/contraction of the components of the equipments (B) Pressure drop in the equipment will be very high (C) Viscosity variation of the fluids may cause channelling/flooding (D) None of these

Description : Plate towers are preferred to packed towers, when large temperature changes are involved, because of the reason that the (A) Packing may be crushed due to thermal expansion/contraction of the ... C) Viscosity variation of the fluids may cause channelling/flooding (D) None of these

Last Answer : (A) Packing may be crushed due to thermal expansion/contraction of the components of the equipments

Even though heat transfer co-efficient in boiling liquids is large, use of fins is advantageous, when the entire surface is exposed to __________ boiling. (A) Film (B) Nucleate (C) Transition (D) All modes of

Description : Even though heat transfer co-efficient in boiling liquids is large, use of fins is advantageous, when the entire surface is exposed to __________ boiling. (A) Film (B) Nucleate (C) Transition (D) All modes of

Last Answer : Option A

Extremely large or small volumes of fluids are generally best routed through the shell side of a shell and tube heat exchanger, because of the (A) Less corrosion problems (B) Flexibility possible in the baffle arrangement (C) Low pressure drop (D) High heat transfer co-efficient

Description : Extremely large or small volumes of fluids are generally best routed through the shell side of a shell and tube heat exchanger, because of the (A) Less corrosion problems (B) Flexibility possible in the baffle arrangement (C) Low pressure drop (D) High heat transfer co-efficient

Last Answer : (B) Flexibility possible in the baffle arrangement

In a shell and tube heat exchanger, floating head is used for (A) Large temperature differentials (B) High heat transfer co-efficient (C) Low pressure drop (D) Less corrosion of tubes

Description : In a shell and tube heat exchanger, floating head is used for (A) Large temperature differentials (B) High heat transfer co-efficient (C) Low pressure drop (D) Less corrosion of tubes

Last Answer : (A) Large temperature differentials

Pick out the wrong statement about nucleate boiling. (A) Bubble generation is by expansion of entrapped gas/vapour at small cavities in the surface (B) Surface temperature is greater than the saturation temperature of the liquid (C) Heat transfer from the surface of the liquid is less than that in film boiling (D) The temperature is less than that of film boiling

Description : Pick out the wrong statement about nucleate boiling. (A) Bubble generation is by expansion of entrapped gas/vapour at small cavities in the surface (B) Surface temperature is greater than the saturation ... less than that in film boiling (D) The temperature is less than that of film boiling

Last Answer : (D) The temperature is less than that of film boiling

It is desired to concentrate a 20% salt solution (20 kg of salt in 100 kg of solution) to a 30% salt solution in an evaporator. Consider a feed of 300 kg/min at 30°C. The boiling point of the solution is 110°C, the latent heat of vaporisation is 2100 kJ/kg and the specific heat of the solution is 4 kJ/kg.K. The rate at which the heat has to be supplied in (kJ/min) to the evaporator is (A) 3.06 × 10 5 (B) 6.12 × 10 5 (C) 7.24 × 10 5 (D) 9.08 × 10

Description : It is desired to concentrate a 20% salt solution (20 kg of salt in 100 kg of solution) to a 30% salt solution in an evaporator. Consider a feed of 300 kg/min at 30°C. The boiling point of the solution is 110°C, the latent heat of ... 3.06 10 5 (B) 6.12 10 5 (C) 7.24 10 5 (D) 9.08 10

Last Answer : (A) 3.06 × 10

For the same heat load and mass flow rate in the tube side of a shell and tube heat exchanger, one may use multipass on the tube side, because it (A) Decreases the pressure drop (B) Decreases the outlet temperature of cooling medium (C) Increases the overall heat transfer coefficient (D) None of these

Description : For the same heat load and mass flow rate in the tube side of a shell and tube heat exchanger, one may use multipass on the tube side, because it (A) Decreases the pressure drop (B) ... the outlet temperature of cooling medium (C) Increases the overall heat transfer coefficient (D) None of these

Last Answer : (C) Increases the overall heat transfer coefficient

Heat transfer rate to the stock/charge in the furnace does not depend upon the(A) Emissivity of the refractory walls(B) Size of the furnace(C) Use of waste heat recovery equipments(D) Thickness of the stock

Description : Heat transfer rate to the stock/charge in the furnace does not depend upon the (A) Emissivity of the refractory walls (B) Size of the furnace (C) Use of waste heat recovery equipments (D) Thickness of the stock

Last Answer : (C) Use of waste heat recovery equipments

Heat flux increases with temperature drop beyond the Leiden frost point in the plot of heat flux vs. temperature drop for a boiling liquid, because (A) Convection becomes important (B) Conduction becomes important (C) Radiation becomes important (D) Sub-cooled boiling occurs

Description : Heat flux increases with temperature drop beyond the Leiden frost point in the plot of heat flux vs. temperature drop for a boiling liquid, because (A) Convection becomes important (B) Conduction becomes important (C) Radiation becomes important (D) Sub-cooled boiling occurs

Last Answer : (C) Radiation becomes important

For large heat transfer area requirement, shell and tube heat exchanger is preferred, because it (A) Occupies smaller space (B) Is more economical (C) Is easy to operate and maintain (D) All (A), (B) and (C)

Description : For large heat transfer area requirement, shell and tube heat exchanger is preferred, because it (A) Occupies smaller space (B) Is more economical (C) Is easy to operate and maintain (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Economy of a multiple effect evaporator is not influenced much by the (A) Boiling point elevations (B) Temperature of the feed (C) Rate of heat transfer (D) Ratio of the weight of the thin liquor to thick liquor

Description : Economy of a multiple effect evaporator is not influenced much by the (A) Boiling point elevations (B) Temperature of the feed (C) Rate of heat transfer (D) Ratio of the weight of the thin liquor to thick liquor

Last Answer : (A) Boiling point elevations

Which of the following situations can be approximated to a steady state heat transfer system? (A) A red hot steel slab (having outside surface temperature as 1300°C) exposed to the atmospheric air at 35°C (B) 10 kg of dry saturated steam at 8 kgf/cm2 flowing through a short length of stainless steel pipe exposed to atmospheric air at 35°C (C) Boiling brine kept in open vessel when the bottom surface temperature of the vessel is maintained constant at 180°C (D) A sub-cooled refrigerant liquid at 8°C flowing at the rate of 6 Kg/minute through a copper pipe exposed to atmospheric air at 35°C

Description : Which of the following situations can be approximated to a steady state heat transfer system? (A) A red hot steel slab (having outside surface temperature as 1300°C) exposed to the atmospheric air at ... flowing at the rate of 6 Kg/minute through a copper pipe exposed to atmospheric air at 35°C

Last Answer : (B) 10 kg of dry saturated steam at 8 kgf/cm2 flowing through a short length of stainless steel pipe exposed to atmospheric air at 35°C

Multipass heat exchangers are used (A) Because of simplicity of fabrication (B) For low heat load (C) To obtain higher heat transfer co-efficient and shorter tube (D) To reduce the pressure drop

Description : Multipass heat exchangers are used (A) Because of simplicity of fabrication (B) For low heat load (C) To obtain higher heat transfer co-efficient and shorter tube (D) To reduce the pressure drop

Last Answer : (C) To obtain higher heat transfer co-efficient and shorter tube

Pick out the wrong statement. (A) Mechanical agitation is required, if the system has low interfacial tension (B) Sieve tray towers are generally used for systems having low interfacial tension (C) When Henry's law constant is very small, then the mass transfer rate is controlled by the gas film resistance (D) Taylor-Prandtl analogy for heat and mass transfer considers the transfer through both laminar and turbulent layers

Description : Pick out the wrong statement. (A) Mechanical agitation is required, if the system has low interfacial tension (B) Sieve tray towers are generally used for systems having low ... Prandtl analogy for heat and mass transfer considers the transfer through both laminar and turbulent layers

Last Answer : (A) Mechanical agitation is required, if the system has low interfacial tension

Water is normally used as a coolant in the heat exchange equipments mainly because of its (A) Abundance & high heat capacity (B) Low density (C) Low viscosity (D) High fluidity

Description : Water is normally used as a coolant in the heat exchange equipments mainly because of its (A) Abundance & high heat capacity (B) Low density (C) Low viscosity (D) High fluidity

Last Answer : (A) Abundance & high heat capacity

Finned tube heat exchangers (A) Give larger area per tube (B) Use metal fins of low thermal conductivity (C) Facilitate very large temperature drop through tube wall (D) Are used for smaller heat load

Description : Finned tube heat exchangers (A) Give larger area per tube (B) Use metal fins of low thermal conductivity (C) Facilitate very large temperature drop through tube wall (D) Are used for smaller heat load

Last Answer : (A) Give larger area per tube

. A dilute aqueous solution is to be concentrated in an evaporator system. High pressure steam is available. Multiple effect evaporator system is employed, because (A) Total heat transfer area of all the effects is -less than that in a single effect evaporator system (B) Total amount of vapor produced per Kg of feed steam in a multiple effect system is much higher than in a single effect (C) Boiling point elevation in a single effect system is much higher than that in any effect in a multi-effect system (D) Heat transfer co-efficient in a single effect is much lower than that in any effect in a multi-effect system

Description : . A dilute aqueous solution is to be concentrated in an evaporator system. High pressure steam is available. Multiple effect evaporator system is employed, because (A) Total heat transfer area of ... in a single effect is much lower than that in any effect in a multi-effect system

Last Answer : (B) Total amount of vapor produced per Kg of feed steam in a multiple effect system is much higher than in a single effect

At high altitudes it is difficult to cook eggs or vegetables properly because of (a) High boiling point of water and low atmospheric pressure (b) Low boiling point of water and low atmospheric pressure (c) Low value of acceleration due to gravity (d) High atmospheric pressure and low billing point of water

Description : At high altitudes it is difficult to cook eggs or vegetables properly because of (a) High boiling point of water and low atmospheric pressure (b) Low boiling point of water and low atmospheric ... Low value of acceleration due to gravity (d) High atmospheric pressure and low billing point of water

Last Answer : Ans:(b)

Low viscosity absorbent is preferred for reasons of (A) Rapid absorption rates and good heat transfer characteristics (B) Improved flooding characteristics (C) Low pressure drop on pumping (D) All (A), (B) and (C)

Description : Low viscosity absorbent is preferred for reasons of (A) Rapid absorption rates and good heat transfer characteristics (B) Improved flooding characteristics (C) Low pressure drop on pumping (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Which of the following parameters is increased by use of finned tube in a multipass shell and tube heat exchanger? (A) Tube side pressure drop and the heat transfer rate (B) Convective heat transfer co-efficient (C) Effective tube surface area for convective heat transfer (D) All (A) (B) and (C)

Description : Which of the following parameters is increased by use of finned tube in a multipass shell and tube heat exchanger? (A) Tube side pressure drop and the heat transfer rate (B) Convective heat transfer co-efficient (C) Effective tube surface area for convective heat transfer (D) All (A) (B) and (C)

Last Answer : (D) All (A) (B) and (C)

As the difference between the wall temperature and bulk temperature increases, the boiling heat transfer co-efficient (A) Continues to increase (B) Continues to decrease (C) Goes through a minimum (D) Goes through a maximum

Description : As the difference between the wall temperature and bulk temperature increases, the boiling heat transfer co-efficient (A) Continues to increase (B) Continues to decrease (C) Goes through a minimum (D) Goes through a maximum

Last Answer : (C) Goes through a minimum

A single pass air heater is connected to a two pass unit. For the air flow rate and other conditions remaining the same, the film heat transfer co￾efficient for air will vary in the ratio of (A) 2 (B) 2 0.8 (C) 2 0.2 (D) 2 0.5

Description : A single pass air heater is connected to a two pass unit. For the air flow rate and other conditions remaining the same, the film heat transfer co￾efficient for air will vary in the ratio of (A) 2 (B) 2 0.8 (C) 2 0.2 (D) 2 0.5

Last Answer : (B) 2 0.8

Pick out the correct statement about the condensation. (A) Filmwise condensation gives a lower heat transfer rate than the dropwise condensation (B) Suitable coating or vapour additive is used to promote film wise condensation (C) If a condensing liquid does not wet the surface dropwise, even then condensation will take place on it (D) Reynolds number of condensing liquid is based on its mass flow rate

Description : Pick out the correct statement about the condensation. (A) Filmwise condensation gives a lower heat transfer rate than the dropwise condensation (B) Suitable coating or vapour additive is used to promote film ... place on it (D) Reynolds number of condensing liquid is based on its mass flow rate

Last Answer : (B) Suitable coating or vapour additive is used to promote film wise condensation

Water is a better coolant than a gas (like CO2 , He, N2 etc.), because it (A) Is a better neutron moderator as well (B) Require comparatively smaller pumps and heat exchanger for a given heat transfer rate (C) Has a better heat transfer characteristics, and it can be pressurised to attain a high temperature (D) All (A), (B) and (C)

Description : Water is a better coolant than a gas (like CO2 , He, N2 etc.), because it (A) Is a better neutron moderator as well (B) Require comparatively smaller pumps and heat exchanger for a given heat transfer rate ... , and it can be pressurised to attain a high temperature (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Dislocation cross-slip is difficult in those materials, which have (A) Large number of slip systems (B) High work hardening rate (C) Coarse grain size (D) Low stacking fault energy

Description : Dislocation cross-slip is difficult in those materials, which have (A) Large number of slip systems (B) High work hardening rate (C) Coarse grain size (D) Low stacking fault energy

Last Answer : (D) Low stacking fault energy

Crude oil is subjected to vacuum distillation in the last stage, because (A) High boiling point products like heavy fuel oil & lubricating oils are heat sensitive and may decompose (B) Lighter/low boiling products are prone to thermal decomposition (C) High purity products can be obtained thereby (D) None of these

Description : Crude oil is subjected to vacuum distillation in the last stage, because (A) High boiling point products like heavy fuel oil & lubricating oils are heat sensitive and may decompose (B) Lighter/low ... prone to thermal decomposition (C) High purity products can be obtained thereby (D) None of these

Last Answer : (A) High boiling point products like heavy fuel oil & lubricating oils are heat sensitive and may decompose

Pick out the correct statement. (A) Ponchan-Savarit method is more accurate than McCabe-Thiele method to determine the number of theoretical stages required for the separation of non￾ideal binary system by distillation (B) A sharp decrease in pressure drop is an indication of flooding in a distillation coloumn (C) Solvent used in extractive distillation should be of high volatility (D) Flash distillation is suitable for separating components which have very close boiling temperature

Description : Pick out the correct statement. (A) Ponchan-Savarit method is more accurate than McCabe-Thiele method to determine the number of theoretical stages required for the separation of ... Flash distillation is suitable for separating components which have very close boiling temperature

Last Answer : (A) Ponchan-Savarit method is more accurate than McCabe-Thiele method to determine the number of theoretical stages required for the separation of non￾ideal binary system by distillation

The actual temperature drop across the heating surface of an evaporator depends on the (A) Liquid depth over the heating surface (B) Solution being evaporated (C) Pressure difference between the steam chest and the vapor space above the boiling liquid (D) All (A), (B) and (C)

Description : The actual temperature drop across the heating surface of an evaporator depends on the (A) Liquid depth over the heating surface (B) Solution being evaporated (C) Pressure difference between the steam chest and the vapor space above the boiling liquid (D) All (A), (B) and (C)

Last Answer : (D) All (A), (B) and (C)

Pick out the wrong statement. (A) In drying a solid containing moisture above the critical moisture content the number of degrees of freedom is 2 (B) Sherwood number in mass transfer corresponds to Nusselt number in heat transfer and Schmidt number to Prandtl number (C) Forced convection is relatively more effective in increasing the rate of mass transfer, if Schmidt number is larger (D) Hot gases at moderate pressure are usually in the shell side of shell and tube heat exchangers. At higher pressure, however, it is customary to put gas in the tube side

Description : Pick out the wrong statement. (A) In drying a solid containing moisture above the critical moisture content the number of degrees of freedom is 2 (B) Sherwood number in mass transfer corresponds to ... tube heat exchangers. At higher pressure, however, it is customary to put gas in the tube side

Last Answer : (C) Forced convection is relatively more effective in increasing the rate of mass transfer, if Schmidt number is larger

What is the marketing objective of non-business organizations ? 1. To provide an idea or service to the public 2. To obtain a desired response from a target market or public 3. To obtain a return on social investment 4. To determine the target market and to create and maintain a satisfying marketing mix 5. none of these

Description : What is the marketing objective of non-business organizations ? 1. To provide an idea or service to the public 2. To obtain a desired response from a target market or public 3. To obtain ... To determine the target market and to create and maintain a satisfying marketing mix 5. none of these

Last Answer : To obtain a desired response from a target market or public

What is the marketing objective of nonbusiness organisations? A)To provide an idea or service to the public B)To obtain a desired response from a target market or public C)To obtain a return on social investment D)To determine the target market and to create and maintain a satisfying marketing mix

Description : What is the marketing objective of nonbusiness organisations? A)To provide an idea or service to the public B)To obtain a desired response from a target market or public C)To obtain a return on social investment D)To determine the target market and to create and maintain a satisfying marketing mix

Last Answer : B)To obtain a desired response from a target market or public

Which of the following is not a desirable property of a refrigerant (a) highmisibility with oil (b) low boiling point (c) good electrical conductor (d) large latent heat

Description : Which of the following is not a desirable property of a refrigerant (a) highmisibility with oil (b) low boiling point (c) good electrical conductor (d) large latent heat

Last Answer : Ans: c

The jet thrusters are usually fired to A. maintain altitude B. put the satellite into the transfer orbit C. inject the satellite in the geosynchronous orbit D. bring the satellite back to earth.

Description : The jet thrusters are usually fired to A. maintain altitude B. put the satellite into the transfer orbit C. inject the satellite in the geosynchronous orbit D. bring the satellite back to earth.

Last Answer : A. maintain altitude

Pick out the wrong statement. (A) In case of heat transfer by purely forced convection, GR /Re 2 ≤ 1 (B) The equivalent diameter of heat transfer for a duct of square cross￾section (having each side as 'x') is equal to 4x (C) Distillation process is not the same as evaporation (D) The effectiveness of nucleate boiling depends basically on the ease with which the bubbles are formed and detached from the heating surface

Description : Pick out the wrong statement. (A) In case of heat transfer by purely forced convection, GR /Re 2 ≤ 1 (B) The equivalent diameter of heat transfer for a duct of ... nucleate boiling depends basically on the ease with which the bubbles are formed and detached from the heating surface

Last Answer : (B) The equivalent diameter of heat transfer for a duct of square cross￾section (having each side as 'x') is equal to 4x

Leidenfrost point is a term concerned with the (A) Condensation of the saturated vapor on a cold surface (B) Concentration of a corrosive solution by evaporation (C) Heat transfer between two highly viscous liquids (D) Boiling of a liquid on a hot surface

Description : Leidenfrost point is a term concerned with the (A) Condensation of the saturated vapor on a cold surface (B) Concentration of a corrosive solution by evaporation (C) Heat transfer between two highly viscous liquids (D) Boiling of a liquid on a hot surface

Last Answer : (D) Boiling of a liquid on a hot surface

Pick out the wrong statement. (A) 'Solvates' are chemical compounds formed by solute with their solvents. When water is the solvent, then it is called a 'hydrate' (B) In heat exchanger calculations (Δt) weighted is used in place of Δt, when it involves more than one sequence of heating or cooling i.e., desuperheating & condensation or condensation & sub-cooling (C) Heat transfer co-efficient during nucleate boiling is not influenced by the agitation imparted (D) In case of short tube vertical evaporators, area of central downtake is about 50 to 100% of the total tube cross-sectional area

Description : Pick out the wrong statement. (A) 'Solvates' are chemical compounds formed by solute with their solvents. When water is the solvent, then it is called a 'hydrate' (B) In heat exchanger ... vertical evaporators, area of central downtake is about 50 to 100% of the total tube cross-sectional area

Last Answer : (C) Heat transfer co-efficient during nucleate boiling is not influenced by the agitation imparted

Pick out the wrong statement. (A) Heat transfer from a hot body to cold body by the emission of heat waves is called radiation (B) Filmwise condensation takes place on non-wettable surfaces (C) The boiling point of a solution is affected by liquid head as well as boiling point elevation (D) None of these

Description : Pick out the wrong statement. (A) Heat transfer from a hot body to cold body by the emission of heat waves is called radiation (B) Filmwise condensation takes place on non-wettable surfaces (C) The ... of a solution is affected by liquid head as well as boiling point elevation (D) None of these

Last Answer : (B) Filmwise condensation takes place on non-wettable surfaces

In a counter-current liquid extractor (A) Both liquids flow at fixed rate (B) Both liquids can have any desired flow rate (C) Only one of the liquids may be pumped at any desired rate (D) Liquid’s flow rate depends upon the temperature and pressure

Description : In a counter-current liquid extractor (A) Both liquids flow at fixed rate (B) Both liquids can have any desired flow rate (C) Only one of the liquids may be pumped at any desired rate (D) Liquid’s flow rate depends upon the temperature and pressure

Last Answer : (C) Only one of the liquids may be pumped at any desired rate

A packed tower compared to a plate tower for a particular mass transfer operation (A) Incurs smaller pressure drop (B) Allows installation of cooling coils (C) Is less costly when built in large sizes/diameters (D) Is more suitable, if suspended solids are present in fluid stream

Description : A packed tower compared to a plate tower for a particular mass transfer operation (A) Incurs smaller pressure drop (B) Allows installation of cooling coils (C) Is less costly when built in large sizes/diameters (D) Is more suitable, if suspended solids are present in fluid stream

Last Answer : (A) Incurs smaller pressure drop

Whe a large number of investors in a country transfer investments elsewhere because of disturbed economic conditions, it is called - (1) Transfer of Capital (2) Escape of Capital (3) Outflow of Capital (4) Flight of Capital

Description : Whe a large number of investors in a country transfer investments elsewhere because of disturbed economic conditions, it is called - (1) Transfer of Capital (2) Escape of Capital (3) Outflow of Capital (4) Flight of Capital

Last Answer : (4) Flight of Capital Explanation: Flight of capital refers to the movement of money from one investment to another in search of greater stability or increased returns. Sometimes, it ... in massive foreign capital outflows from a specific country, often at times of currency instability.

When a large number of investors in a country transfer investments elsewhere because of disturbed economic conditions, it is called (1) Transfer of Capital (2) Escape of Capital (3) Outflow of Capital (4) Flight of Capital

Description : When a large number of investors in a country transfer investments elsewhere because of disturbed economic conditions, it is called (1) Transfer of Capital (2) Escape of Capital (3) Outflow of Capital (4) Flight of Capital 

Last Answer :  Flight of Capital 

Higher boiling fractions like atmospheric residue is distilled under vacuum at low temperature because at high temperature, there is a tendency of the predominance of(A) Thermal cracking(B) Gum formation(C) Coking(D) Discoloration

Description : Higher boiling fractions like atmospheric residue is distilled under vacuum at low temperature because at high temperature, there is a tendency of the predominance of (A) Thermal cracking (B) Gum formation (C) Coking (D) Discoloration

Last Answer : (C) Coking

Steam distillation is not recommended to be used, if the (A) Azeotropic mixture is to be separated and the final product is miscible with water (B) Liquids decompose, if distilled directly at atmospheric pressure (C) Material cannot be distilled by indirect heating even under low pressure, because of the high boiling temperature (D) Material to be distilled is thermally unstable or has the tendency to react with other components associated with it, at the boiling temperature

Description : Steam distillation is not recommended to be used, if the (A) Azeotropic mixture is to be separated and the final product is miscible with water (B) Liquids decompose, if ... unstable or has the tendency to react with other components associated with it, at the boiling temperature

Last Answer : (A) Azeotropic mixture is to be separated and the final product is miscible with water

Boiling point of water gets lowered at high altitudes (e.g., hills), because (A) Temperature is low (B) Atmospheric pressure is low (C) Atmospheric pressure is high (D) None of these

Description : Boiling point of water gets lowered at high altitudes (e.g., hills), because (A) Temperature is low (B) Atmospheric pressure is low (C) Atmospheric pressure is high (D) None of these

Last Answer : Option B

Increasing the liquor level in the evaporator results in the (A) Decreased capacity (B) Increase in liquor film co-efficient (C) Decreased effect of hydrostatic head (D) Increased true temperature drop

Description : Increasing the liquor level in the evaporator results in the (A) Decreased capacity (B) Increase in liquor film co-efficient (C) Decreased effect of hydrostatic head (D) Increased true temperature drop

Last Answer : (A) Decreased capacity

The film co-efficient between condensing vapour and metal wall increases with (A) Increasing temperature of the vapour (B) Decreasing temperature of the vapour (C) Increasing viscosity of the film of condensate (D) Increasing temperature drop

Description : The film co-efficient between condensing vapour and metal wall increases with (A) Increasing temperature of the vapour (B) Decreasing temperature of the vapour (C) Increasing viscosity of the film of condensate (D) Increasing temperature drop

Last Answer : (A) Increasing temperature of the vapour