Bioprocess Engineering Flashcards
Which lines indicate wet bulb temperatures in the psychometric charts?
a) Diagonals lines
b) Vertical lines
c) Horizontal lines
d) Curves
a) Diagonals lines
Which lines indicate dry bulb temperatures in the psychometric chart?
a) Diagonals lines
b) Vertical lines
c) Horizontal lines
d) Curves
b) Vertical lines
Which lines indicate relative humidity in the psychometric charts?
a) Diagonals lines
b) Vertical lines
c) Horizontal lines
d) Curves
d) Curves
What is another name for humidity ratio?
a) Mixing ratio
b) Water ratio
c) Relative humidity ratio
d) Bound water ratio
a) Mixing ratio
Who invented the psychometric chart?
a) Dr Richard Seligman
b) George Babcock
c) George Brayton
d) Willis H. Carrier
d) Willis H. Carrier
This helps to decide the stability of food at particular moisture content in the given environment
a. equilibrium moisture content
b. psychometric charts
c. equilibrium moisture content and psychometric charts
d. chemical properties and psychometric charts
a. equilibrium moisture content
when there is an equilibrium in moisture content, no change in moisture content, thus stability
Rate of drying depends on which of the following statement?
Statement 1: Vapor pressure of water at drying temperature.
Statement 2: Vapor pressure in the external environment.
a) True, False
b) True, True
c) False, True
d) False, False
b) True, True
Rate of drying depends on
1. equilibrium vapor pressure of water
2. moisture of the food
3. vapor pressure of water at drying temperature
4. vapor pressure in the external environment
Which of the following statements are true about drying?
Statement 1: Latent heat of vaporization is not necessary.
Statement 2: Moisture must be transported out from the food.
a) True, False
b) True, True
c) False, True
d) False, False
c) False, True
What happens to the drying rate when it reaches critical moisture content?
a) Declines
b) Increases gradually
c) Stops
d) Becomes constant
a) Declines
What is the independent factor of the constant rate period?
a) Moisture content
b) Temperature
c) Pressure
d) Humidity
a) Moisture content
Name the phenomenon which transfers moisture during second falling drying rate period?
a) Liquid diffusion
b) Capillary movement
c) Vapor diffusion
d) Liquid diffusion, capillary movement, and vapor diffusion
d) Liquid diffusion, capillary movement, and vapor diffusion
How does humidity affect drying rate?
a) No effect
b) Directly proportional
c) Indirect proportional
d) Linear increase
b) Directly proportional
What happens to the drying rate during constant rate of drying period?
a) It reduces
b) It increases
c) Constant
d) Becomes negligible
b) It increases
- What is the mass of water vapor present in 1 kg of dry air called?
a) Specific Humidity
b) Relative humidity
c) Degree of saturation
d) Saturated air
a) Specific Humidity
What is the ratio of actual mass of water vapor in a given volume of moist air to the mass of water vapor in the same volume of saturated air at the same pressure and temperature?
a) Specific Humidity
b) Relative humidity
c) Degree of saturation
d) Saturated air
b) Relative humidity
What is the ratio of actual mass of water vapor in a unit mass of dry air to the mass of water vapor in the same mass of dry air when it is saturated at the same temperature?
a) Moist air
b) Dry air
c) Degree of saturation
d) Saturated air
c) Degree of saturation
Specific humidity and absolute humidity have the same unit.
a) False
b) True
a) False
When the adiabatic mixing is carried out, the air having ___ enthalpies and _____ specific humidities are mixed.
a. similar, similiar
b. different, similar
c. similar, different
d. different, different
d. different, different
The two air streams getting mixed adiabatically have different enthalpies and different specific humidities to get the final condition of air.
During humidification process, the dry bulb temperature _____
a. increases
b. decreases
c. tends to zero
d. remains the same
d. remains the same
During the sensible cooling process, specific humidity decreases
a. True
b. False
b. False
During sensible cooling process, the dry bulb temperature decreases. It is a horizontal process on a psychrometric chart. Hence, the specific humidity neither increases nor decreases, but there might be some change in relative humidity.
Mixture of dry air and water vapor is ____
a. moist air
b. dry air
c. fresh air
d. saturated air
a. moist air
What is the temperature of air recorded by a thermometer when the moisture present in it starts condensing?
a. DBT
b. WBT
c. DPT
d. WBD
c. DPT or dew point temperature
it is also the temperature corresponding to the partial pressure of water vapor
What is the temperature of air recorded by the thermometer when it is not affected by the moisture present in it?
a. DBT
b. WBT
c. DPT
d. sub-zero temperature
a. DBT
For unsaturated air, the value of DPT is ________ WBT
a. less than
b. more than
c. equal to
d. much more than
a. less than
Moist air containing moisture in the superheated state is called unsaturated air. In this case DPT < WBT
What is the difference between DBT and WBT called?
a. DPD
b. DBD
c. Degree of saturation
d. WBD
d. WBD or wet bulb depression
indicates relative humidity of the air
Will DPT, DBT and WBT have the same value? At what condition?
a. it’s impossible
b. yes, 0% RH
c. Yes, 100% RH
c. Yes, 100% RH
DPT, DBT, and WBT converge at one point when the air is saturated (RH = 100%)
A study that deals with the principles and practices of processing agricultural products suitable for food and feeds.
a. Agricultural processing
b. Food processing
c. Feed processing
d. All of the above
a. Agricultural processing
A study that deals with the application and practices in converting agricultural products into different kinds and forms of food suitable for animal consumption.
a. Agricultural processing
b. Food processing
c. Feed processing
d. All of the above
c. Feed processing
A study that deals with the application and practices in converting agricultural products into different kinds and forms of food.
a. Agricultural processing
b. Food processing
c. Feed processing
d. All of the above
b. Food processing
These are crops that are produced and harvested with normally low moisture content of about 20 to 30% and do not easily deteriorate or spoil.
a. Perishable crops
b. Durable crops
c. Flexible crops
d. None of the above
b. Durable crops
These are crops that have high moisture content of 30% and more such as fruits and vegetables including dairy, meat, poultry, and fish and easily deteriorate or spoil.
a. Perishable crops
b. Durable crops
c. Flexible crops
d. None of the above
a. Perishable crops
Processing operation which changes the physical properties of the product such as processing banana into catsup.
a. Primary processing
b. Secondary processing
c. Tertiary processing
d. None of the above
b. Secondary processing
Processing operation which does not significantly change the physical characteristics of the product such as drying and dehydration of fruits and vegetables.
a. Primary processing
b. Secondary processing
c. Tertiary processing
d. None of the above
a. Primary processing
Which country does not belong to the ASEAN Free Trade Agreement?
a. China
b. Japan
c. Korea
d. All of the above
e. None of the abov
d. All of the above
Brunei, Indonesia, Malaysia, the Philippines, Singapore and Thailand
The study that deals with fluids at rest such as those fluids like coconut oil, milk, etc.
a. Hydrodynamic
b. Hydrostatic
c. Hydro pneumatic
d. None of the above
b. Hydrostatic
The study that deals with the various factors affecting the relationship between the rate of flow of fluid and the various pressures tending it to cause or inhibit its flow.
a. Hydrodynamic
b. Hydrostatic
c. Hydro pneumatic
d. None of the above
a. Hydrodynamic
Which of the following resources are considered fluid?
a. Biogas
b. Producer gas
c. Bioethanol
d. Coconut oil
e. Sugar cane juice
f. All of the above
g. None of the above
f. All of the above
Which of the following resources are not fluid?
a. Biomass
b. Grains and Cereals
c. Fruits and vegetables
d. All of the above
d. All of the above
Newton’s law of motion states that:
a. Everybody continues in a state of rest or of uniform motion in a straight line unless compelled by force to change that state.
b. The rate of change of momentum is proportional to the force applied and took place in the direction of the force application.
c. To every action there is always an equal and opposite reaction.
d. All of the above
d. All of the above
Mass flow rate states that:
a. The rate of flow of fluid is constant at any point in the system and there is no accumulation or depletion of fluid within the system.
b. The rate of flow of fluid is not constant at any point in the system and there is accumulation or depletion of fluid within the system.
c. The rate of flow of fluid increases at any point of the system and there is accumulation and no depletion within the system.
d. None of the above
a. The rate of flow of fluid is constant at any point in the system and there is no accumulation or depletion of fluid within the system.
Fluids include ___.
a. solid, gas, and liquid
b. gas and liquid
c. liquid
d. All of the above
b. gas and liquid
The characteristic of agricultural products that determines the angle by
which it will move freely by gravity with respect to the material in which it is held, such as hopper bottom of a storage bin structure.
a. Angle-of-repose
b. Angle-of-friction
c. Angle-of-slide
d. None of the above
b. Angle-of-friction
This refers to the characteristics of fluid that is linearly related to shear force.
a. Newtonian fluid
b. Non-Newtonian fluid
c. All of the above
d. None of the above
a. Newtonian fluid
An example of Newtonian fluid.
a. Coconut oil
b. Butter
c. Slurries
d. None of the above
a. Coconut oil
This refers to the characteristics of fluid not linear with the shear force.
a. Newtonian fluid
b. Non-Newtonian fluid
c. All of the above
d. None of the above
b. Non-Newtonian fluid
An example of Non-Newtonian fluid.
a. Purees
b. Jathropha oil
c. Coconut water
d. None of the above
a. Purees
This refers to the internal resistance of fluid to shear.
a. Viscosity
b. Coefficient-of-friction of fluid to fluid
c. All of the above
d. None of the above
c. All of the above
Reynolds number is a function of the ___.
a. inside diameter of the pipe
b. velocity of fluid inside the pipe
c. specific weight of the fluid
d. fluid viscosity
e. All of the above
f. None of the above
e. All of the above
Reynolds number equation.
a. Re = DVδ/μ
b. Re = DV/μ
c. Re = DV/δμ
d. None of the above
a. Re = DVδ/μ
When fluids flow in elemental swirl or eddies, it is classified as ___.
a. turbulent flow
b. laminar flow
c. mixture of laminar and turbulent flow
d. None of the above
a. turbulent flow
When fluids flow in parallel elements, it is classified as ___.
a. turbulent flow
b. laminar flow
c. mixture of laminar and turbulent flow
d. None of the above
b. laminar flow
Which of the following factors affect the flow of fluid in pipes?
a. Characteristics of fluid
b. Size of pipe
c. Shape of pipe
d. Condition inside the surface of the pipe
e. Fluid velocity
f. All of the above
g. None of the above
f. All of the above
Which of the following statements is true?
a. The velocity of fluid flowing in a pipe is highest at the center and decreases towards its surfaces.
b. The velocity gradient for streamlined flow in a long circular conduit is parabolic in shape.
c. The velocity gradient for turbulent flow flattens and the relationship between the maximum and the average velocity changes.
d. All of the above
e. None of the above
d. All of the above
The angle formed by agricultural product itself with respect to the horizontal axis which varies with the moisture content and the amount of foreign matter.
a. Angle-of-repose
b. Angle-of-friction
c. Angle-of-slide
d. None of the above
a. Angle-of-repose
A simple device used to measure pressure by taking the difference in the height of fluid inside a tube.
a. Pyschrometer
b. Hydrometer
c. Manometer
d. None of the above
c. Manometer
The pressure taken from the direction of fluid which is also the pressure resulting from force due to change in velocity of the fluid.
a. Static pressure
b. Dynamic pressure
c. Isothermic pressure
d. None of the above
b. Dynamic pressure
The pressure taken perpendicular from the direction of fluid where sample application of which is taking the velocity of flow of fluid in pipes using pitot-tube manometer.
a. Static pressure
b. Dynamic pressure
c. Isothermic pressure
d. None of the above
a. Static pressure
The unit of pressure.
a. Psi
b. Inches of water
c. Inches of mercury
d. All of the above
e. None of the above
d. All of the above
High pressure is usually expressed in ___.
a. psi
b. inches of water
c. inches of mercury
d. All of the above
e. None of the above
a. psi
Low pressure is usually expressed in ___.
a. psi
b. inches of water
c. inches of mercury
d. All of the above
e. None of the above
b. inches of water
Very low pressure is usually expressed in ___.
a. psi
b. inches of water
c. inches of mercury
d. All of the above
e. None of the above
c. inches of mercury
In fluid mechanics, the total hydraulic energy is the sum of ___ energy plus the work supplied by the pump or blower less friction (conduit and fittings) in the system.
a. potential and kinetic
b. pressure and kinetic
c. potential, kinetic, and pressure
d. None of the above
c. potential, kinetic, and pressure
An open tube pointing to the direction of flow of the fluid that is usually used with manometer to measure static and dynamic pressures.
a. Pitot-Tube
b. Orifice
c. Weir
d. None of the above
a. Pitot-Tube
Which of the following instruments can measure the flow of fluid?
a. Pitot tube
b. Venturi meter
c. Hot wire anemometer
d. All of the above
e. None of the above
d. All of the above
Which of the following fluids is considered as highly incompressible?
a. Flue gases
b. Biogas
c. Vegetable oil
d. All of the above
c. Vegetable oil
Which of the following fluids is considered as compressible?
a. Producer gas
b. Vegetable oil
c. Molasses
d. None of the above
a. Producer gas
The mass flow rate equation:
a. Q = AVδ
b. Q = AV
c. Q = Aδ
d. None of the above
a. Q = AVδ
The available energy due to the elevation above a reference plane.
a. Pressure Energy
b. Kinetic Energy
c. Potential Energy
d. None of the above
c. Potential Energy
The available energy due to the internal pressure.
a. Pressure Energy
b. Kinetic Energy
c. Potential Energy
d. None of the above
a. Pressure Energy
The energy available from moving fluids.
a. Pressure Energy
b. Kinetic Energy
c. Potential Energy
d. None of the above
b. Kinetic Energy
The process which results in the diffusion of substances from the region of high concentration to the region of low concentration.
a. Energy transfer
b. Mass transfer
c. Heat transfer
d. None of the above
b. Mass transfer
The amount of heat transfer from within the product.
a. Thermal diffusivity
b. Thermal conductivity
c. Thermal expansion
d. None of the above
b. Thermal conductivity
The unhulled grain of Oryza sativa.
a. Palay
b. Paddy
c. Rough rice
d. All of the above
d. All of the above
The fibrous layer of paddy when hull is removed and is commonly known as the silver skin of brown rice.
a. Lemma and Palea
b. Pericarp
c. Bran layer
d. None of the above
b. Pericarp
An angle with tangent equals the coefficient of friction between surfaces of the stored materials.
a. Angle-of-contact
b. Angle-of-friction
c. Angle-of-repose
d. All of the above
b. Angle-of-friction
The drying temperature of copra is ___.
a. less than 50°C
b. between 50° to 95°C
c. above 95°C
d. None of the above
b. between 50° to 95°C
The density of pig and poultry feeds is approximately ___.
a. 250 kg/m3
b. 450 kg/m3
c. 650 kg/m3
d. None of the above
b. 450 kg/m3
The slender-type paddy has ___ length to width ratio.
a. less than 2.0
b. between 2 to 3
c. more than 3.0
d. None of the above
c. more than 3.0
The free space between the husk of rough rice and the brown rice kernel greatly affects milling in the sense that ___.
a. the larger the free space the greater is the amount of broken grains
b. the smaller the free space the lesser its abrasive effect to the
rubber-roll huller
c. the larger the free space, the lesser the breakage and losses
d. All of the above
c. the larger the free space, the lesser the breakage and losses
The uneven expansion and contraction of the inner and the outer layers of the grains that cause fissuring is a factor of ___.
a. mechanical stress
b. thermal stress
c. physical stress
d. All of the above
e. None of the above
b. thermal stress
The property of a product that holds moisture when subjected to a prolong condition of known temperature and relative humidity.
a. Dry matter loss
b. Mass transfer coefficient
c. Equilibrium moisture content
d. None of the above
c. Equilibrium moisture content
The specific gravity of rice.
a. 1.11 to 1.12
b. 1.19 to 1.30
c. 1.22 to 1.26
d. None of the above
a. 1.11 to 1.12
The specific gravity of sorghum.
a. 1.11 to 1.12
b. 1.19 to 1.30
c. 1.22 to 1.26
d. None of the above
c. 1.22 to 1.26
The bulk density of rough rice.
a. 25 lbs/ft3
b. 36 lbs/ft3
c. 45 lbs/ft3
d. None of the above
b. 36 lbs/ft3
The specific gravity of corn.
a. 1.11 to 1.12
b. 1.19 to 1.30
c. 1.22 to 1.26
d. None of the above
b. 1.19 to 1.30
The physical properties of important agricultural processing.
a. Surface area
b. Porosity
c. Bulk density
d. Angle-of-repose
e. Angle-of-friction
f. All of the above
f. All of the above
The angle-of-repose of rough rice.
a. 27 degrees
b. 33 degree
c. 36 degrees
d. None of the above
c. 36 degrees
The angle-of-repose of shelled corn.
a. 27 degrees
b. 33 degree
c. 36 degrees
d. None of the above
a. 27 degrees
The angle-of-repose of sorghum.
a. 27 degrees
b. 33 degree
c. 36 degrees
d. None of the above
b. 33 degree
The angle-of-friction of rough rice in steel.
a. 0.41
b. 0.37
c. 0.36
d. None of the above
a. 0.41
The angle-of-friction of shelled corn in steel.
a. 0.41
b. 0.37
c. 0.36
d. None of the above
b. 0.37
The angle-of-friction of soybean in steel.
a. 0.41
b. 0.37
c. 0.36
d. None of the above
c. 0.36
Which of the following thermal properties are important in agricultural processing?
a. Thermal conductivity
b. Specific heat
c. Coefficient of thermal expansion
d. Heat of vaporization
e. Thermal diffusivity
f. All of the above
f. All of the above
The thermal conductivity of paddy
grain ___ linearly with temperature, bulk density, and moisture content.
a. increases
b. decreases
c. do not increase or decrease
d. None of the above
a. increases
The bulk density of shelled corn.
a. 25 lbs/ft3
b. 36 lbs/ft3
c. 45 lbs/ft3
d. None of the above
c. 45 lbs/ft3
The amount of heat required to raise the temperature of the product one degree higher when heat is added.
a. Heat of vaporization
b. Specific heat
c. Thermal diffusivity
d. None of the above
b. Specific heat
The amount of heat required to remove a certain amount of moisture from the product.
a. Heat of vaporization
b. Specific heat
c. Thermal diffusivity
d. None of the above
a. Heat of vaporization
Hygroscopic properties important in agricultural processing.
a. Equilibrium moisture content
b. Mass transfer coefficient
c. Dry matter loss
d. Tempering period
e. All of the above
e. All of the abovec
The mass transfer among agricultural products is a function of ___.
a. air temperature
b. air relative humidity
c. airflow rate
d. thickness
e. All of the above
e. All of the above
The equivalent loss in the dry matter of a product due to respiration during storage.
a. Moisture loss
b. Dry matter loss
c. Respiration loss
d. None of the above
b. Dry matter loss
The terminal velocity of rough rice.
a. 1.3 to 5.2 m/s
b. 6.0 to 7.1 m/s
c. 7.5 to 9.0 m/s
d. None of the above
b. 6.0 to 7.1 m/s
The pressure drop in the product during drying is a function of ___.
a. airflow
b. amount of foreign matter present
c. moisture content
d. depth of drying
e. All of the above
e. All of the above
Which of the following rice variety that is characterized by short and bold?
a. Japonica
b. Indica
c. Java
d. None of the above
a. Japonica
Which of the following variety that is characterized by long and slender?
a. Indica
b. Java
c. All of the above
d. None of the above
a. Indica
Variety of rice which is difficult to threshed?
a. Japonica
b. Indica
c. Java
d. All of the above
a. Japonica
Variety of rice which is easy to cracked when pass through a rubber rice mill?
a. Japonica
b. Indica
c. Java
d. None of the above
e. Two of the above
e. Two of the above
The amount of moisture in the grain expressed as a percentage of the total weight of the samples.
a. Moisture content dry basis
b. Moisture content wet basis
c. Moisture content
d. All of the above
b. Moisture content wet basis
The amount of moisture in the grain expressed as a percentage of the weight of dry matter.
a. Moisture content dry basis
b. Moisture content wet basis
c. Moisture content
d. None of the above
a. Moisture content dry basis
A moisture meter that determines the moisture content of the product based on the ability of the current to pass through the material.
a. Capacitance-type moisture meter
b. Resistance-type meter
c. Infrared moisture meter
d. All of the above
b. Resistance-type meter
When the amount of water in a product is determined based on its dry matter content, the moisture content is expressed in ___.
a. wet basis
b. dry basis
c. semi wet basis
d. None of the above
b. dry basis
The method of measuring the moisture content of the product by direct extraction of water.
a. Primary method
b. Secondary method
c. Tertiary method
d. None of the above
a. Primary method
Which of the following is considered primary method in determining moisture content?
a. Oven method
b. Distillation method
c. Infrared method
d. All of the above
e. None of the above
d. All of the above
An expression of moisture content commonly used in commercial scale.
a. Moisture content wet basis
b. Moisture content dry basis
c. Moisture content
d. All of the above
a. Moisture content wet basis
Which of the following is considered secondary method in determining moisture content?
a. Electrical-resistance method
b. Electrical-capacitance method
c. Chemical method
d. Hygrometric method
e. All of the above
f. None of the above
e. All of the above
The moisture found at the surface of the material.
a. Unbound water (Free moisture)
b. Bound water
c. Chemically bound
d. All of the above
a. Unbound water (Free moisture)
An important index to determine whether the paddy is ready for harvesting, storage or milling.
a. Color
b. Moisture content
c. Hardness
d. None of the above
b. Moisture content
The moisture inside the tissue of a material that can only be removed by heating or reducing the vapor pressure within the material.
a. Chemically-bound moisture
b. Bound moisture
c. Unbound
d. All of the above
b. Bound moisture
The difficult-to-remove moisture from the product that requires other method than heating in order to remove it.
a. Chemically-bound moisture
b. Bound moisture
c. Free moisture
d. All of the above
a. Chemically-bound moisture
A plot or a graph representing the equilibrium moisture content of grains at different relative humidity but with constant temperature.
a. Isothermal graph
b. Sorption isotherms
c. Isothermal humidity
d. None of the above
b. Sorption isotherms
The appliance usually used in calibrating resistance- and capacitor-type moisture meters.
a. Oven
b. Distillation
c. Infrared
d. All of the above
a. Oven
The device used by the industry in determining moisture content of grains.
a. Oven
b. Electrical resistance- and
capacitance-type meter
c. Infrared moisture meter
d. All of the above
b. Electrical resistance- and
capacitance-type meter
The process of removing contaminants from the product.
a. Sorting
b. Grading
c. Cleaning
d. None of the above
c. Cleaning
The process of separating cleaned products in various quality fractions that maybe defined based on the size, shape, texture, colors, and other factors.
a. Sorting
b. Grading
c. Cleaning
d. None of the above
b. Grading
Which of the following parameters are taken into consideration during cleaning and grading products?
a. Size
b. Weight
c. Surface Texture
d. Affinity to liquid
e. Color
f. Shape
g. All of the above
g. All of the above
The rough cleaning of paddy removing most foreign materials prior to drying and storage.
a. Aspiration
b. Scalping
c. Sieving
d. All of the above
b. Scalping
Self-cleaning sieves used for rice mills basically consist of ___.
a. a brush to remove particles that clogs the screen of the cleaner
b. one or two balls that continuously hammer the top sieve of the cleaner
c. assigned operator to do the cleaning while the machine is operating
d. None of the above
b. one or two balls that continuously hammer the top sieve of the cleaner
The process of separating lower density materials from grains.
a. Aspiration
b. Cleaning
c. Fanning
d. All of the above
a. Aspiration
A kind of cleaner that uses air in separating lesser-density materials from corn kernel/corn grits such as floured corn, germ and bran.
a. Aspirator
b. Oscillating screen
c. Cleaner
d. Cyclone separator
e. All of the above
a. Aspirator
A machine used to remove hard materials of almost the same size as milled rice through gravity separation
using air stream to cause rice grains to be carried away by the air stream leaving heavy materials behind.
a. Aspirator
b. De-stoner
c. Sifter
d. None of the above
b. De-stoner
The machine used to separate grains according to color or reflectivity.
a. Color meter
b. Electronic color sorter
c. Electric color separator
d. None of the above
c. Electric color separator
A primary cleaner which separates larger particles from rice, also known as “rough cleaning” of rough rice.
a. Rotary sieve
b. Scalper
c. Vibrating screen
d. All of the above
b. Scalper
The recommended size of scalper for paddy is ___.
a. 0.2-0.25sq.m. per ton
b. 0.3-0.35sq.m. per ton
c. 0.4-0.45sq.m. per ton
d. None of the above
a. 0.2-0.25sq.m. per ton
A type of screen cleaners that uses air blast to assist in the cleaning.
a. Screen separator
b. Fanning mill
c. Blower
d. None of the above
b. Fanning mill
The percentage of grains free from foreign matter.
a. Percentage foreign matter
b. Percentage Cleanliness
c. Purity
d. None of the above
c. Purity
When removing light particles from threshed grains that goes with the chaffs during operation, what would be the best course of action that you should recommend as an Agricultural Engineer in order to achieve better cleaning and separation?
a. Install additional perforated sheets in the cleaning system.
b. Provide an air-blast system using a blower so it can carry light particles.
c. Reduce the feeding of threshed grains.
d. None of the above
b. Provide an air-blast system using a blower so it can carry light particles.
A grain separator for seed based on the affinity for liquid or on the rate at which the surface of the seed absorbs liquid.
a. Vibrator separator
b. Aspirator
c. Magnetic separator
d. None of the above
c. Magnetic separator
A separator used for particles with low and high terminal velocity.
a. Air-blast separator
b. Aspirator
c. Fanning mill
d. None of the above
b. Aspirator
Vibrator separator is recommended for separating grains based on ___.
a. weight
b. surface texture
c. size
d. None of the above
b. surface texture
The amount of foreign materials in a sample of grains.
a. Impurities
b. Chalky grain
c. Dockage
d. None of the above
c. Dockage
The material commonly used in separating grains from chaffs according to size.
a. Indented plate
b. Perforated sheet
c. Steel screen
d. All of the above
b. Perforated sheet
When using a cylindrical slotted rotating screen or sheet, the material can be separated in terms of ___.
a. weight
b. shape
c. thickness
d. None of the above
c. thickness
Indented rotating cylinders are usually used for separating grains in terms of ___.
a. thickness
b. width and length
c. size
d. None of the above
b. width and length
Air blast separation is effective for separating the product based on ___.
a. size
b. weight
c. length
d. None of the above
b. weight
Precleaners are provided for the rice milling plant primarily to ___ and to improve the quality of the final product.
a. add for the machine requirement
b. protect other processing equipment
c. reduce the load
d. None of the above
b. protect other processing equipment
Magnetic separator basically is installed in the rice milling plant before the ___.
a. precleaner
b. husker
c. whitener
d. polisher
e. None of the above
a. precleaner
In a tray-type paddy separator, brown rice moves at the ___ of the tray.
a. bottom
b. middle
c. top
d. None of the above
c. top
A separation equipment coupled to the end of a pneumatic conveyor to separate solid particles from the air stream.
a. Magnetic separator
b. Cyclone separator
c. Vibratory separator
d. None of the above
b. Cyclone separator
Efficiency of ordinary cyclone ranges from ___.
a. 80 to 90%
b. 95 to 98%
c. 98 to 99%
d. None of the above
a. 80 to 90%
The process of making too-large-to be-used solid materials usable.
a. Size reduction
b. Grinding
c. Cutting
d. All of the above
a. Size reduction
Size-reduction processes include ___.
a. cutting
b. crushing
c. grinding
d. All of the above
d. All of the above
Raw materials for feeds are processed primarily using a size-reduction equipment to ___.
a. increase the surface area of contact of the material to facilitate taking place of reaction
b. make it palatable when used as feed for animals
c. facilitate conveyance operation at the feed mill
f. All of the above
a. increase the surface area of contact of the material to facilitate taking place of reaction
A physical mechanism used in size reduction process.
a. Compression
b. Impact
c. Attrition
d. Cutting
f. All of the above
f. All of the above
Which of the following statements is true in relation to size-reduction operation?
a. Size reduction is the most inefficient unit operation in terms of energy use.
b. Size reduction is the most efficient unit operation in terms of energy use.
c. Size reduction is neither efficient nor inefficient unit operation in terms of energy use
d. None of the above
a. Size reduction is the most inefficient unit operation in terms of energy use.
Which of the following statements is true in relation to reducing particle size of a material?
a. Reduction of materials to very fine sizes is more costly in terms of energy as compared with reduction to relatively coarse particles.
b. Reduction of materials to very fine sizes is much cheaper in terms of energy as compared with reduction to relatively coarse particles.
c. Reduction of materials to very fine sizes has the same cost as with reduction to relatively coarse particles.
d. None of the above
a. Reduction of materials to very fine sizes is more costly in terms of energy as compared with reduction to relatively coarse particles.
Which of the following is an example of size-reduction processes?
a. Chopping corn fodder
b. Slicing of sweet potato
c. Milling of cassava into flour
d. All of the above
c. Milling of cassava into flour
A trade term used relative to the reduction of grains into meal or flour.
a. Shredding
b. Crushing
c. Milling
d. None of the above
c. Milling
Vertical-axis hammer mill is more advantageous to use than horizontal-axis for the reason that:
a. It is more effective in grinding grains with higher moisture content of
up to 25%.
b. The power requirement of the vertical-axis hammer mill is much lower than that of the horizontal-axis hammer
mill.
c. Less broken grains can be derived from vertical-axis.
d. None of the above
a. It is more effective in grinding grains with higher moisture content of
up to 25%.
Size-reduction machines are
characterized based on ___.
a. capacity
b. power required unit material reduce
c. size and shape of the product after reduction
d. range of size and shape of resulted product
e. All of the above
e. All of the above
The process of reducing the size of materials by applying force to the product in excess of its strength.
a. Shearing
b. Crushing
c. Milling
d. None of the above
b. Crushing
The process of reducing the size of materials by pushing or forcing a thin sharp knife into it.
a. Shearing
b. Crushing
c. Cutting
d. All of the above
c. Cutting
The process of reducing the size of materials by cutting and crushing actions.
a. Milling
b. Grinding
c. Shearing
d. None of the above
c. Shearing
The power requirement in reducing the size of grains is ___ for moist grains than for dried grains.
a. lesser
b. the same
c. higher
d. None of the above
c. higher
An indicator of the uniformity of ground materials in the resultant product.
a. Uniformity index
b. Particle size
c. Fineness modulus
d. All of the above
c. Fineness modulus
The power requirement of size reduction equipment is ___ for fibrous than for crystalline materials.
a. lesser
b. the same
c. higher
d. None of the above
c. higher
Performance characteristics of size reduction equipment are based on ___.
a. size uniformity
b. temperature rise
c. power requirement
d. trouble-free operation
e. All of the above
e. All of the above
Hammer mills are designed purposely to ___.
a. chop forage materials
b. reduce the sizes of granular products
c. compact powdered product
d. None of the above
b. reduce the sizes of granular products
A type of mill used for crushing grains by allowing it to pass through two rotating-cylinder steels, one of which is smaller than the other.
a. Hammer mill
b. Roller mill
c. Plate mill
d. All of the above
b. Roller mill
The size-reduction machine usually used in feed milling to break dried grains into suitable size for feeds.
a. Hammer mill
b. Roller mill
c. Burr mill
d. None of the above
a. Hammer mill
In hammer milling, the fineness of a material is determined by the ___.
a. number of hammers
b. speed of hammer
c. size of hole of the screen
d. None of the above
c. size of hole of the screen
The energy requirement of a hammer mill in grinding shelled corn.
a. 7.4 kw-hr/ton
b. 5.8 kw-hr/ton
c. 2.3 kw-hr/ton
d. None of the above
a. 7.4 kw-hr/ton
When reduced material size is between 1/8 in. or more, it is classified as ___.
a. microscopic range
b. sieve range
c. dimension range
d. None of the above
c. dimension range
When reduced material size is less than 0.0029 in., it is classified as ___.
a. microscopic range
b. sieve range
c. dimension range
d. None of the above
a. microscopic range
When reduced material size is between 0.125 to 0.0029 in., it is classified as ___.
a. microscopic range
b. sieve range
c. dimension range
d. None of the above
b. sieve range
Sieves used in determining the fineness modulus of a material includes 3/8-, 4-, 8-, 14-, 28-, 48-. and ___ -in. mesh.
a. 60
b. 80
c. 100
d. None of the above
c. 100
A cassava processing plant is required to grind fresh cassava into flour, what size-reduction machine would you
recommend as an Agricultural Engineer?
a. Hammer mill
b. Roller mill
c. Burr mill
d. None of the above
c. Burr mill
In burr milling, the size of grind can be varied by ___.
a. varying the size of the screen opening
b. varying the pressure on the plates
c. varying the opening between rolls
d. None of the above
b. varying the pressure on the plates
The operating speed of burr mills.
a. Less than 1200 rpm
b. 1200 to 2400 rpm
c. 2400 to 3200 rpm
d. None of the above
a. Less than 1200 rpm
A grain milling machine consisting of two cast-iron disk plates with teeth or serration on one or on both faces.
a. Hammer mill
b. Attrition mill
c. Roller mill
d. All of the above
b. Attrition mill
A burr or plate mill.
a. Micro mill
b. Attrition mill
c. Roller mill
d. All of the above
b. Attrition mill
A device used for classifying granular materials by passing through series of screens.
a. Tyler sieves
b. Tyler screen
c. Tyler separator
d. None of the above
a. Tyler sieves
The most suitable machine for
reducing size of materials like forages, straws, stalks, and weeds.
a. Hammer mill
b. Roller mill
c. Burr mill
d. Cutter mill
e. All of the above
d. Cutter mill
A grain milling machine suitable for grinding grains with moisture content of up to 30%.
a. Hammer mill
b. Attrition or burr mill
c. Roller mill
d. All of the above
b. Attrition or burr mill
The operating speed of burr mills.
a. Less than 1200 rpm
b. 1200 to 2400 rpm
c. 2400 to 3200 rpm
d. None of the above
a. Less than 1200 rpm
The speed of hammer mills.
a. 200 to 1000 rpm
b. 1500 to 4000 rpm
c. 4500 to 6000 rpm
d. None of the above
b. 1500 to 4000 rpm
During grinding, the temperature of the material ___ when grinding fibrous than granular material.
a. decreases
b. increases
c. does not change
d. None of the above
b. increases
The factor affecting the power requirement of grinding mill.
a. Type of material
b. Moisture content of material
c. Fineness of grinding of material
d. Rate of feeding the material
e. Type and condition of mill
f. All of the above
f. All of the above
The rotating disk of the burr mill can be found ___.
a. near the hopper
b. away from the hopper
c. underneath the hopper
d. None of the above
b. away from the hopper
The biomass shredder employs ___ in producing shredded products.
a. cutting and crushing by twisting pressure
b. cutting and crushing by impact
c. cutting and shearing
d. None of the above
a. cutting and crushing by twisting pressure
A forage chopper employs ___.
a. cutting
b. crushing
c. shearing
d. None of the above
c. shearing
Hammer mill is protected from foreign objects by making it ___.
a. fix in position to the shaft
b. swing freely in the shaft
c. detachable from the the screen
d. None of the above
b. swing freely in the shaft
Which of the following size-reduction equipment operates by crushing method?
a. Hammer mill
b. Attrition mill
c. Roller mill
d. All of the above
c. Roller mill
An Important reason for reducing the size of a product.
a. Easy handling
b. Increase surface area per unit volume
c. Separation of entrapped components
d. All of the above
d. All of the above
A kind of grinder for intermediate grinding which uses round shaped metals inside a cylinder that breaks the material finely by impact action.
a. Caster mill
b. Roller mill
c. Ball mill
d. All of the above
c. Ball mill
which of the following statements is true?
a. Size reduction is to make too large solids to be usable.
b. Size reduction increases the surface area per unit volume of the material which enhances the rate of reaction.
c. Size reduction makes handling of materials much easier.
d. All of the above
d. All of the above`
The process of combining different materials until a certain degree of homogeneity is achieved.
a. Milling
b. Mixing
c. Feeding
d. None of the above
b. Mixing
The assembling and measuring of the needed amount of every solid raw feed material in the formulation of the desired composition of a mixture.
a. Mixing
b. Blending
c. Pelleting
d. All of the above
b. Blending
The blending of ingredients or of materials in agricultural processing operation.
a. Sorting
b. Molding
c. Mixing
d. All of the above
c. Mixing
Basically, the purpose of mixing is ___.
a. to promote the transfer of heat between hot and cold products
b. to obtain good contact between materials being mixed
c. to promote reactions between reactants
d. All of the above
e. Any two of the above
d. All of the above
During mixing, heavier particles tend to remain ___ of the container.
a. near the bottom
b. away from the bottom
c. at the middle
d. None of the above
a. near the bottom
An indicator of satisfactory mixing.
a. Produce uniform mixture
b. Less time in mixing materials
c. Less cost
d. All of the above
e. None of the above
d. All of the above
Feed materials are purposely mixed to ___.
a. obtain a homogenous feed to ensure that animals are given the same proportions of nutrient
b. reduce the density of the feed material so that it can be easily transported
c. improve the digestability of feeds
d. None of the above
a. obtain a homogenous feed to ensure that animals are given the same proportions of nutrient
During mixing, round or small particles tend to move towards the ___ of the container.
a. top
b. middle
c. bottom
d. All of the above
a. top
Difficulty in mixing may result if the solid particles has ___.
a. the same size but of different specific gravity
b. different sizes
c. different shapes
d. All of the above
d. All of the above
If mixing is needed during conveying, the suitable conveyor to use is ___ type.
a. bucket
b. screw
c. belt
d. All of the above
b. screw
A mixer with U-shaped bin containing a central mixing blade or a ribbon mounted on a rotating shaft.
a.Horizontal mixer
b.Inclined mixer
c.Vertical mixer
d.All of the above
a.Horizontal mixer
A feed mixer characterized by high capacity, short mixing time, and high power requirement.
a.Horizontal mixer
b.Inclined mixer
c.Vertical mixer
d.All of the above
a.Horizontal mixer
Horizontal feed mixer is not advantageous for feed mixing as compared with vertical feed mixer for the reason that ___.
a.it has lower capacity
b.it has high power requirement
c.it has shorter life span
d.None of the above
b.it has high power requirement
A feed mixer characterized by low capacity, longer mixing time and low power requirement.
a. Horizontal mixer
b. Inclined mixer
c. Vertical mixer
d. All of the above
c. Vertical mixer
A feed mixer with an auger that elevates the feed to the top of the mixing bin and spreads them evenly throughout by gravity for another mixing cycle.
a.Horizontal mixer
b.Vertical mixer
c.Inclined mixer
d.All of the above
b.Vertical mixer
The auger that is centrally located in a vertical feed mixer and usually rotates at ___ speed.
a.100-250 rpm
b.250-400 rpm
c.400-650 rpm
d.None of the above
b.250-400 rpm
A type of mixer suitable for either free flowing or non-free flowing materials.
a.Rotating mixer without stirrers
b.Rotating mixer with stirrers
c.All of the above
d.None of the above
b.Rotating mixer with stirrers
The type of mixer satisfactory for extensively large operations.
a. Batch-type mixer
b. Semi-continuous-type mixer
c. Continuous-type mixer
d. None of the above
c. Continuous-type mixer
The type of mixer suitable for moderate to small operation in which overhead cost is low and labor cost is not critical.
a. Batch-type mixer
b. Semi-continuous-type mixer
c. Continuous-type mixer
d. None of the above
a. Batch-type mixer
Difficulty in mixing often occurs if the solids are ___ size and shape but of different specific gravity.
a. not the same
b. the same
c. either the same or not the same
d.None of the above
b. the same
Mixing of particles is also difficult if they have ___ size and shape.
a. the same
b. different
c. All of the above
d. None of the above
b. different
Heavier particles remains at the ___ during mixing.
a. top
b. middle
c. bottom
d. All of the above
c. bottom
The small size batch-type mixer.
a. Rotating drum with flights
b. U-shaped mixer with rotating flights and paddles
c. Vertical mixer with central auger
d. None of the above
a. Rotating drum with flights
A ___ mixer basically uses a number of mixers in which feed materials are loaded into one mixer at a time and are emptied into a common conveyor or storage.
a. batch
b. semi-continuous
c. continuous
d. None of the above
b. semi-continuous
