193 + Mcqs in Unit Operations Diffusion Mass Transfer Page 2 McqOptions

51.	Statement 1: The solubility of NaCl increases with the increase in temperature.Statement 2: Crystal formation is hindered by nucleation taking place on the crystal surface.
A.	True, False
B.	True, True
C.	False, False
D.	False, True
Answer» C. False, False

Discussion

52.	Statement 1: Smaller particles dissolve as they have a larger surface area and larger particles grow.Statement 2: The above process is called Ostwald ripening.
A.	True, False
B.	True, True
C.	False, False
D.	False, True
Answer» C. False, False

Discussion

53.	_____ is an important solvent for wet and edible materials.
A.	Hexane
B.	Acetone
C.	Chloroform
D.	All of the mentioned
Answer» B. Acetone

Discussion

54.	Automated valves should be avoided.
A.	True
B.	False
C.	May be True or False
D.	Can't say
Answer» B. False

Discussion

55.	Incrustation leads to _____
A.	Affects safety
B.	Damages equipment
C.	Affects product quality
D.	All of the mentioned
Answer» E.

Discussion

56.	Which theory proposes that the film is continuously getting renewed and replaced by the bulk liquid?
A.	Film theory
B.	Penetration theory
C.	Surface renewal theory
D.	None of the mentioned
Answer» D. None of the mentioned

Discussion

57.	Statement 1: Solid food items containing water molecules are more soluble as the temperature increases.Statement 2: This growth takes place in steps.
A.	True, False
B.	True, True
C.	False, False
D.	False, True
Answer» C. False, False

Discussion

58.	Which of the following tells the significance of crystallization in food processing?
A.	Consistency of food emulsions
B.	A good feel of food inside the mouth
C.	The physical stability of food
D.	All of the mentioned
Answer» E.

Discussion

59.	_____ is the diagonal of the x-y diagram.
A.	Operating line
B.	Equilibrium line
C.	Equilibrium curve
D.	None of the mentioned
Answer» C. Equilibrium curve

Discussion

60.	Heating on the surface of a heat exchanger leads to fouling.
A.	True
B.	False
C.	May be True or False
D.	Can't say
Answer» B. False

Discussion

61.	Celinium Sulphate is an exception of the solubility curve. When the temperature is increased, its solubility decreases.
A.	True
B.	False
C.	May be True or False
D.	Can't say
Answer» B. False

Discussion

62.	Using hot water for decoction followed by spraying drying is the procedure used for making instant coffee.
A.	True
B.	False
C.	May be True or False
D.	Can't say
Answer» B. False

Discussion

63.	What is extraction in paprika used for?
A.	Obtain proteins from the end product
B.	Desolventization of final product
C.	Extraction of its natural color
D.	All of the mentioned
Answer» D. All of the mentioned

Discussion

64.	Moisture on dry basis cannot be more than a hundred percentage.
A.	True
B.	False
C.	May be True or False
D.	Can't say
Answer» C. May be True or False

Discussion

65.	Ratio of equilibrium concentrations of solute A in liquid phase and gas phase i.e. CAL* and CAg* respectively is α. α is called _____
A.	Diffusion coefficient
B.	Distribution coefficient
C.	Mass transfer coefficient
D.	None of the mentioned
Answer» C. Mass transfer coefficient

Discussion

66.	The feed line tells us that a particular feed A is at a sub-cooled liquid. Which of the following explains the above statement?
A.	The liquid is at its boiling point
B.	None of the mentioned
C.	A liquid below its boiling temperature
D.	The liquid is a mixture of boiling and some vapors
Answer» D. The liquid is a mixture of boiling and some vapors

Discussion

67.	Statement 1: Cabinet tray dyers can be used for heat sensitive materials.Statement 2: Bin dryer is used for materials which follow the falling rate drying curve.
A.	True, False
B.	True, True
C.	False, False
D.	False, True
Answer» E.

Discussion

68.	Ethanol-water mixture is a popular example of a mixture exhibiting the typical VLE curve.
A.	True
B.	False
C.	May be True or False
D.	Can't say
Answer» C. May be True or False

Discussion

69.	Extremely small packing is favorable for packed towers as the surface area increases.
A.	True
B.	False
C.	May be True or False
D.	Can't say
Answer» C. May be True or False

Discussion

70.	Statement 1: Partition coefficient pertains to solid-liquid extraction.Statement 2: Leaching involves both heat and mass transfer.
A.	True, False
B.	True, True
C.	False, False
D.	False, True
Answer» D. False, True

Discussion

71.	Which of the following dryers is used for making baby food?
A.	Pneumatic conveyor dryer
B.	Drum dryer
C.	Freeze dryer
D.	Spray dryer
Answer» C. Freeze dryer

Discussion

72.	Drying rate curve is plot between _____ and _____
A.	Critical moisture content, critical humidity
B.	Critical moisture content, drying rate
C.	Critical humidity, drying rate
D.	Moisture content, drying rate
Answer» E.

Discussion

73.	With respect to ammonia-water system –Statement 1: Limiting ratio is when the __(1)___ will meet __(2)__Statement 2: When the flow rate of liquid is high, the distance between (1) and (2) decreases.
A.	Operating line will meet Equilibrium curve, false
B.	Equilibrium curve will meet Equilibrium line, true
C.	Operating line will meet Equilibrium line, true
D.	All of the mentioned
Answer» B. Equilibrium curve will meet Equilibrium line, true

Discussion

74.	Statement 1: When alcohol is allowed to move from chamber A to chamber B when a barrier between them is removed, it is called multi phase diffusion.Statement 2: When oxygen is made to diffuse into the water, it’s called continuous molecular diffusion.
A.	True, False
B.	True, True
C.	False, False
D.	False, True
Answer» E.

Discussion

75.	Statement 1: Which tray dryer has indirect heating?Statement 2: Which tray dryer is good for making powders?
A.	Bin dryer, vacuum dryer
B.	Tray dryer, vacuum dryer
C.	Tower Dryer, vacuum dryer
D.	Vacuum dryer, vacuum dryer
Answer» E.

Discussion

76.	Statement 1: Removing of moisture content for grains in the food industry follows the thin layer model of drying bed.Statement 2: The model for removing moisture from grains is computerized to find out the exact amount of time of exposure of grains for the removal of moisture.
A.	True, False
B.	True, True
C.	False, False
D.	False, True
Answer» C. False, False

Discussion

77.	When a system doesn’t obey Raoult’s law, the relative volatility is the ratio of the Henry’s constants for the two systems.
A.	True
B.	False
C.	May be True or False
D.	Can't say
Answer» B. False

Discussion

78.	Which of the following is a process/method to enhance the amount of pure distillate?
A.	Rectification
B.	Stripping
C.	Re-fluxing
D.	All of the mentioned
Answer» E.

Discussion

79.	Which of the following facilitates crystallization?
A.	Hot concentrated solution is cooled for crystals to form
B.	Solution is concentrated by evaporation
C.	Adiabatic evaporation and cooling
D.	All of the mentioned
Answer» E.

Discussion

80.	Parameters affecting crystallization are ____________
A.	Agitator speed
B.	Population density
C.	Purity of solution
D.	All of the mentioned
Answer» E.

Discussion

81.	Draft tubes _____ crystal-crystal attrition. Crystals _____ bottom.
A.	Increase, should be kept on
B.	Increase, should be kept off
C.	Decrease, should be kept on
D.	Decrease, should be kept off
Answer» E.

Discussion

82.	Statement 1: Caffeine is the active principle in coffee. It cannot be stripped off it.Statement 2: Caffeine can be stripped off coffee by extraction.
A.	True, False
B.	True, True
C.	False, False
D.	False, True
Answer» E.

Discussion

83.	Work of Draft tube in Draft tube baffle crystallizer is _____
A.	Maintaining good circulation rate for slurry
B.	Reducing energy requirement for mixing
C.	Maintaining good circulation rate for slurry & reducing energy requirement for mixing
D.	None of the mentioned
Answer» D. None of the mentioned

Discussion

84.	Which of the following operations is carried out by extraction equipment?
A.	Leaving as little solvent as possible in the spent cake
B.	Bringing intimate contact between solute and solvent
C.	Leaching solute out as quick as possible by letting solute diffuse into the solvent from porous structure of solids
D.	All of the mentioned
Answer» E.

Discussion

85.	In plate evaporator, the heat transfer coefficient is high in spite of low residence time because _____
A.	It deals with high viscosity food items
B.	It is economic
C.	Feed is made to pass as thin film
D.	All of the mentioned reasons
Answer» D. All of the mentioned reasons

Discussion

86.	Which of the following is NOT an important criteria for crystal formation?
A.	Caking characteristics of the crystal
B.	Moisture content
C.	Shape
D.	None of the mentioned
Answer» E.

Discussion

87.	Statement 1: Diffusion is faster than convective mass transfer.Statement 2: Mass transfer is proportional to the area of contact.
A.	True, False
B.	True, True
C.	False, False
D.	False, True
Answer» E.

Discussion

88.	Out of the limited applications of distillation in the food industry, which of the following is an application?
A.	Use in brewer industry
B.	Use in solvent recovery industry
C.	Use in steam distillation
D.	All of the mentioned
Answer» E.

Discussion

89.	On wet basis, the denominator stays constant whereas in moisture content on dry basis, the denominator changes.
A.	True
B.	False
C.	May be True or False
D.	Can't say
Answer» C. May be True or False

Discussion

90.	At a food processing industry, the steam was re-compressed and a small amount of steam at high pressures and temperatures was sent into the next evaporation chamber in a multiple effect evaporator. Which of the following is true with respect to the above sentences?
A.	There might be wear and tear in the evaporator
B.	The overall pressure and temperature of steam increases which is desired
C.	The capacity of the evaporator increases
D.	All of the mentioned
Answer» E.

Discussion

91.	Statement 1: Incrustation may lead to under deposit-corrosion.Statement 2: Scrapers can be used as an agitated medium to avoid incrustation.
A.	True, False
B.	True, True
C.	False, False
D.	False, True
Answer» C. False, False

Discussion

92.	Mixed feed arrangement offers the advantage of omitting the usage of pumps by transferring feed in the direction of low pressure. That’s an advantage taken from forward feeding arrangement.
A.	True
B.	False
C.	May be True or False
D.	Can't say
Answer» B. False

Discussion

93.	Statement 1: Forward feeding requires pumps for the feed at every step.Statement 2: In a backward feeding arrangement, the most concentrated feed is exposed to the maximum steam in order to remove heat. This is its advantage.
A.	True, False
B.	True, True
C.	False, False
D.	False, True
Answer» E.

Discussion

94.	Statement 1: Horizontal tube evaporator is easy for cleaning.Statement 2: Horizontal tube evaporator has a disadvantage of hindering agitation of the feed.
A.	True, False
B.	True, True
C.	False, False
D.	False, True
Answer» C. False, False

Discussion

95.	Statement 1: Bubble point means the feed is at saturated vapor.Statement 2: Dew point means the feed is at boiling point.
A.	True, False
B.	True, True
C.	False, False
D.	False, True
Answer» D. False, True

Discussion

96.	Which of the following is the cheapest filtration equipment?
A.	Plate and frame filter press
B.	Pressure leaf filter press
C.	Continuous Rotary Vacuum Filter Press
D.	None of the mentioned
Answer» B. Pressure leaf filter press

Discussion

97.	Statement 1: Hydrogenation of fats involves liquid-gas phases only.Statement 2: Hydrogenation of fats is known as slurry reactor system.
A.	True, False
B.	True, True
C.	False, False
D.	False, True
Answer» E.

Discussion

98.	Statement 1: Forced circulation liquid evaporator-crystallizer has good CSD control.Statement 2: Draft tube baffle crystallizer is flash evaporated for crystallization.
A.	True, False
B.	True, True
C.	False, False
D.	False, True
Answer» D. False, True

Discussion

99.	Which of the following is true about an agitator vessel?
A.	Small bubbles have a high interfacial area
B.	Bubbles in an agitator vessel are small
C.	Small bubbles have a lower rise velocity
D.	All of the mentioned
Answer» E.

Discussion

100.	Secondary nucleation involves the collision of crystals.
A.	True
B.	False
C.	May be True or False
D.	Can't say
Answer» B. False

Discussion

Explore topic-wise MCQs in Food Engineering.

Statement 1: The solubility of NaCl increases with the increase in temperature.Statement 2: Crystal formation is hindered by nucleation taking place on the crystal surface.

Statement 1: Smaller particles dissolve as they have a larger surface area and larger particles grow.Statement 2: The above process is called Ostwald ripening.

_____ is an important solvent for wet and edible materials.

Automated valves should be avoided.

Incrustation leads to _____

Which theory proposes that the film is continuously getting renewed and replaced by the bulk liquid?

Statement 1: Solid food items containing water molecules are more soluble as the temperature increases.Statement 2: This growth takes place in steps.

Which of the following tells the significance of crystallization in food processing?

_____ is the diagonal of the x-y diagram.

Heating on the surface of a heat exchanger leads to fouling.

Celinium Sulphate is an exception of the solubility curve. When the temperature is increased, its solubility decreases.

Using hot water for decoction followed by spraying drying is the procedure used for making instant coffee.

What is extraction in paprika used for?

Moisture on dry basis cannot be more than a hundred percentage.

Ratio of equilibrium concentrations of solute A in liquid phase and gas phase i.e. CAL* and CAg* respectively is α. α is called _____

The feed line tells us that a particular feed A is at a sub-cooled liquid. Which of the following explains the above statement?

Statement 1: Cabinet tray dyers can be used for heat sensitive materials.Statement 2: Bin dryer is used for materials which follow the falling rate drying curve.

Ethanol-water mixture is a popular example of a mixture exhibiting the typical VLE curve.

Extremely small packing is favorable for packed towers as the surface area increases.

Statement 1: Partition coefficient pertains to solid-liquid extraction.Statement 2: Leaching involves both heat and mass transfer.

Which of the following dryers is used for making baby food?

Drying rate curve is plot between _____ and _____

With respect to ammonia-water system –Statement 1: Limiting ratio is when the __(1)___ will meet __(2)__Statement 2: When the flow rate of liquid is high, the distance between (1) and (2) decreases.

Statement 1: When alcohol is allowed to move from chamber A to chamber B when a barrier between them is removed, it is called multi phase diffusion.Statement 2: When oxygen is made to diffuse into the water, it’s called continuous molecular diffusion.

Statement 1: Which tray dryer has indirect heating?Statement 2: Which tray dryer is good for making powders?

Statement 1: Removing of moisture content for grains in the food industry follows the thin layer model of drying bed.Statement 2: The model for removing moisture from grains is computerized to find out the exact amount of time of exposure of grains for the removal of moisture.

When a system doesn’t obey Raoult’s law, the relative volatility is the ratio of the Henry’s constants for the two systems.

Which of the following is a process/method to enhance the amount of pure distillate?

Which of the following facilitates crystallization?

Parameters affecting crystallization are ____________

Draft tubes _____ crystal-crystal attrition. Crystals _____ bottom.

Statement 1: Caffeine is the active principle in coffee. It cannot be stripped off it.Statement 2: Caffeine can be stripped off coffee by extraction.

Work of Draft tube in Draft tube baffle crystallizer is _____

Which of the following operations is carried out by extraction equipment?

In plate evaporator, the heat transfer coefficient is high in spite of low residence time because _____

Which of the following is NOT an important criteria for crystal formation?

Statement 1: Diffusion is faster than convective mass transfer.Statement 2: Mass transfer is proportional to the area of contact.

Out of the limited applications of distillation in the food industry, which of the following is an application?

On wet basis, the denominator stays constant whereas in moisture content on dry basis, the denominator changes.

At a food processing industry, the steam was re-compressed and a small amount of steam at high pressures and temperatures was sent into the next evaporation chamber in a multiple effect evaporator. Which of the following is true with respect to the above sentences?

Statement 1: Incrustation may lead to under deposit-corrosion.Statement 2: Scrapers can be used as an agitated medium to avoid incrustation.

Mixed feed arrangement offers the advantage of omitting the usage of pumps by transferring feed in the direction of low pressure. That’s an advantage taken from forward feeding arrangement.

Statement 1: Forward feeding requires pumps for the feed at every step.Statement 2: In a backward feeding arrangement, the most concentrated feed is exposed to the maximum steam in order to remove heat. This is its advantage.

Statement 1: Horizontal tube evaporator is easy for cleaning.Statement 2: Horizontal tube evaporator has a disadvantage of hindering agitation of the feed.

Statement 1: Bubble point means the feed is at saturated vapor.Statement 2: Dew point means the feed is at boiling point.

Which of the following is the cheapest filtration equipment?

Statement 1: Hydrogenation of fats involves liquid-gas phases only.Statement 2: Hydrogenation of fats is known as slurry reactor system.

Statement 1: Forced circulation liquid evaporator-crystallizer has good CSD control.Statement 2: Draft tube baffle crystallizer is flash evaporated for crystallization.

Which of the following is true about an agitator vessel?

Secondary nucleation involves the collision of crystals.

Drying rate curve is plot between _ and _

With respect to ammonia-water system –Statement 1: Limiting ratio is when the (1)_ will meet (2)Statement 2: When the flow rate of liquid is high, the distance between (1) and (2) decreases.

Draft tubes _ crystal-crystal attrition. Crystals _ bottom.