PPT 6 Flashcards by Rhealene Cahigas

Which of the following is true?
a. The thermal conductivity of
aluminum is higher than silver
b. Aluminum and silver transfer heat at
the same rate
c. Silver is faster to transmit heat than
aluminum
d. All of the above

c. Silver is faster to transmit heat than
aluminum

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If the flow of fluid is on streamline
characteristics, the fluid is at …
a. Turbulent condition
b. Laminar condition
c. Eddies
d. All of the above

b. Laminar condition

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One BTU/hr-ft-F is equal to:
a. 0.00413 cal/sec-cm-C
b. 1/448 kcal/hr-m-C
c. 0.0173 w/cm-C
d. All of the above
e. None of the above

d. All of the above

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The Prantdl number is a function of
______.
a. Viscosity, specific heat, and
thermal conductivity
b. Viscosity, diameter of pipe, thermal
conductivity
c. Specific heat, heat transfer
coefficient, and thermal
conductivity
d. None of the above

a. Viscosity, specific heat, and
thermal conductivity

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Heat transfer coefficient by force
convection is determined by what
dimensionless numbers?
a. Nusselt, Prandtl, Reynolds
b. Nusselt, Prandtl, Grashof
c. Reynolds, Grashof, Prandtl
d. None of the above

a. Nusselt, Prandtl, Reynolds

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One British thermal unit is equal
to _____
a. 1055 J
b. 1505 J
c. 1550 J
d. None of the above

a. 1055 J

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If the heated pipe is changed to a
higher pipe schedule, the heat
transfer will:
a. Increase
b. Decrease
c. Remains the same
d. All of the above

b. Decrease

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Basically, the thermal conductivity of a
material will increase if the ______
a. Thickness is increased
b. Temperature is increased
c. Temperature is
decreased
d. All of the above

b. Temperature is increased

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Which of the following
statement is true?
a. Heat transfer rate is higher on
edges of boxes
b. Heat transfer rate is lower on
the walls of boxes
c. Heat transfer rate is higher on
corners of boxes
d. None of the above

a. Heat transfer rate is higher on
edges of boxes

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A good insulator for kiln dryer.
a. Rice husk
b. Brick
c. Concrete
d. None of the abov

b. Brick

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A material which is conductor of
heat or has low thermal
conductivity.
a. Conductor
b. Insulator
c. Resistor
d. All of the above

b. Insulator

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An example of a good insulating
material at high temperature.
a. Iron
b. Wood
c. Asbestos
d. All of the above

c. Asbestos

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Which of the following has low
thermal conductivity?
a. Building brick
b. Asbestos
c. Firebrick
d. Concrete

b. Asbestos

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Insulators used for steam lines
are classified into:
a. Low temperature range
insulator
b. High temperature range
insulator
c. Medium temperature range
insulator
d. None of the above

c. Medium temperature range
insulator

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A good example of a dual
temperature insulator.
a. Expanded silica
b. Cellular glass
c. Vermiculite
d. All of the above

d. All of the above

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Form of insulants used in
industrial insulation practice.
a. Flexible strips
b. Foil
c. Flexible pipe section and
mattresses
d. All of the above

d. All of the above

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Which of the following statement is
true?
a. In insulation, heat gain is more
costly than heat loss
b. The cost of extracting heat from
refrigerated space is the same
with the cost of heat losses from
a high temperature system
c. The cost of insulating high
temperature system is the same
with that of low temperature
system
d. All of the above

a. In insulation, heat gain is more
costly than heat loss

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Moisture in low-temperature
insulation material may cause:
a. Reduction in the insulating value of
the material
b. To decrease the cost of the
insulating materials
c. Improvement in the insulating value
of the materials
d. All of the above

a. Reduction in the insulating value of
the material

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An example of materials used
for low-temperature systems.
a. Urethane foam
b. PVC foam
c. Cellular glass
d. All of the above

d. All of the above

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It is an extruded foam used for
low temperature systems such
as refrigeration, Building, and
sub-zero insulation.
a. Polystyrene foam
b. PVC foam
c. Plastic foam
d. All of the above

a. Polystyrene foam

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It is essentially a ceramic material
designed to resist high temperature of
1000 to 1800 C.
a. Refractory
b. Asbestos
c. Fiber glass
d. None of the above

a. Refractory

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Factor that need to be considered in
selecting insulants…
a. Operating temperature
b. Maintenance cost
c. Ability to resist
d. Mechanical and heat damage
e. All of the above

e. All of the above

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To protect insulant from
mechanical damage, the
insulant must be provided with
a. Metal sheet cladding
b. Nets and asbestos cement
c. Wire net and bituminous
compound
d. All of the above

d. All of the above

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The Stefan - Boltzmann
constant is equal to:
a. 0.147 x 10-8BTU/hr-ft2-F4
b. 0.174 x 10-8BTU/hr-ft2-F4
c. 0.174 x 10-8BTU/hr-ft2-F3
d. None of the above

c. 0.174 x 10-8BTU/hr-ft2-F3

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The equation for heat transfer by radiation for gray bodies is a. Qr = AT4 b. Qr = εAT4 c. Qr = εAT4 d. None of the above

b. Qr = εAT4

It is a device used for transferring heat. a. Insulator b. Heat absorber c. Heat exchanger d. All of the above

c. Heat exchanger

The overall heat transfer coefficient includes... a. Thermal conductivity and heat transfer coefficient of the materials b. Heat transfer coefficient and emmissivity of the materials c. Thermal conductivity and emmissivity of the materials d. None of the above

a. Thermal conductivity and heat transfer coefficient of the materials

Which of the following statement is true? a. When radiant energy falls on a body, part may be reflected, absorbed and the remainder transmitted. b. When radiant energy fall on a body, part may be reflected and absorbed. c. When radiant fall on a body, all of the energy are absorbed. d. None of the above

a. When radiant energy falls on a body, part may be reflected, absorbed and the remainder transmitted.

When two fluids in a heat exchanger move in opposite direction, the device is classified as a. Parallel flow HE b. Cross flow HE c. Constant flow HE d. None of the above

b. Cross flow HE

Configuration factor for parallel planes in calculating the heat radiated is a. Higher than perpendicular planes b. Equal to perpendicular planes c. Lower for perpendicular planes d. None of the above

a. Higher than perpendicular planes

It is the process of removing heat from a substance or a space at a lower temperature. a. Sublimation b. Heat of fusion c. Refrigeration d. All of the above

c. Refrigeration

Heat moves from a substance naturally to another substance a. At a higher temperature to lower temperature b. Al lower temperature to higher temperature c. At either temperature d. None of the above

a. At a higher temperature to lower temperature

It is the intensity of the molecular movement of matter. a. Energy b. Heat c. Work d. All of the above

b. Heat

A substance is cold if a. Heat is present b. Heat is absent c. Heat is higher d. All of the above

b. Heat is absent

Ten BTU is equivalent to a. 2520 calories b. 2250 calories c. 2045 calories d. None of the above

a. 2520 calories

The quantity of heat in the substance is described in terms of a. BTU b. Calories c. Pascal d. All of the above

d. All of the above

One-hundred calories is equivalent to: a. 418.7 Joules b. 481.7 Joules c. 471.8 Joules d. None of the above

a. 418.7 Joules

An instrument used to measure heat is a. Thermometer b. Watt meter c. Calorimeter d. None of the above

c. Calorimeter

It is the instrument used to measure heat level is a. Thermometer b. Watt meter c. Calorimeter d. All of the above

a. Thermometer

Which of the following statement is true? a. The freezing point of water is 0°F b. The boiling point of water is 212°C c. That 32°F and 0°C is the same temperature level d. None of the above

c. That 32°F and 0°C is the same temperature level

It is the quantity of heat required to raise the temperature of a substance one degree scale a. Sensible heat b. Specific heat c. Latent heat d. None of the above

b. Specific heat

The specific heat of water is a. 1 BTU/lb-F b. 1 kcal/kg-C c. 1 cal/g-C d. All of the above

d. All of the above

It is the amount of heat added or removed from a substance without changing its state. a. Sensible heat b. Latent heat c. Specific heat d. All of the above

a. Sensible heat

It is the heat added or removed from a substance causing a change in its state without changing its temperature. a. Sensible heat b. Latent heat c. Specific heat d. All of the above

b. Latent heat

It is the quantity of heat required to change a unit mass of a liquid into gaseous state without change in temperature. a. Latent heat of vaporization b. Latent heat of fusion c. Latent heat of condensation d. None of the above

a. Latent heat of vaporization

It is the quantity of heat required to change a unit mass of solid to liquid state without change in temperature. a. Latent heat of vaporization b. Latent heat of fusion c. Latent heat of sublimation d. All of the above

b. Latent heat of fusion

It is the quantity of heat required to change a unit mass of gas to liquid state without change in temperature. a. Latent heat of vaporization b. Latent heat of condensation c. Latent heat of fusion d. All of the above

b. Latent heat of condensation

It is the quantity of heat required to change a unit mass of solid to gas without change in temperature. a. Latent heat of fusion b. Latent heat of vaporization c. Latent heat of sublimation d. None of the above

c. Latent heat of sublimation

The amount of heat transmitted to a wall is a factor of a. Wall thickness b. Temperature difference c. Resistance of heat flow of the wall materials d. All of the above

d. All of the above

The latent heat of fusion of water is a. 336 kJ/kg b. 144 BTU/lb c. All of the above d. None of the above

d. None of the above

At a higher elevation, a. Water will boil at 100°C b. Water will boil above 100°C c. Water will boil below 100°C d. Water will not boil

c. Water will boil below 100°C

A material with high emissivity... a. Will collect more heat b. Will not collect heat c. Will transmit heat d. None of the above

b. Will not collect heat

The basic uses of insulating materials for refrigeration system are a. To retard heat flow b. To prevent surface condensation c. To control noise and vibration d. All of the above

d. All of the above

Which of the following insulating materials for refrigeration system is efficient and least expensive? a. Asbestos b. Styrofoam c. Aluminum foil d. All of the above

b. Styrofoam

It is the cooling coil of refrigeration system. a. Condenser b. Evaporator c. Compressor d. None of the above

b. Evaporator

It is the amount or quantity of current flowing in a circuit. a. Voltage b. Amperage c. Ohms d. None of the above

b. Amperage

It is the electrical pressure of circuit. a. Voltage b. Amperage c. Ohms d. None of the above

a. Voltage

It is the basic part of a refrigeration system which is characterized by a high pressure side. a. Condenser b. Evaporator c. Expansion valve d. All of the above

a. Condenser

It is the part of refrigeration system that causes the circulation of a refrigerant. a. Condenser b. Expansion valve c. Compressor d. None of the above

c. Compressor

A part of refrigeration system that causes the reduction of pressure of the refrigerant. a. Evaporator b. Compressor c. Expansion valve d. All of the above

c. Expansion valve

One ton refrigeration is equal to a. 288,000 BTU/day b. 12,000 BTU/hr c. 200 BTU/min d. All of the above

d. All of the above

It is a fluid that easily boils at a lower temperature. a. Water b. Oil c. Refrigerant d. All of the above

c. Refrigerant

One ton refrigeration is the amount of heat required to melt one ton of ice in ___ a. 12 hours b. 24 min c. One day d. None of the above

c. One day

An example of refrigerant a. Ammonia b. Carbon monoxide c. Methyl bromide d. All of the above

a. Ammonia

Commonly used refrigerant in ice plants. a. Ammonia b. Carbon dioxide c. Methyl chloride d. None of the above

a. Ammonia

A refrigeration appliance that operates at a higher temperature. a. No-frost refrigerator b. Air-conditioner c. Domestic freezer d. All of the above

b. Air-conditioner

The introduction of fresh ambient air to an air-conditioned or refrigerated space. a. Cooling b. Air changes c. Air filtration d. None of the above

b. Air changes

It is the removal of accumulated ice from the surfaces of cooling coils which operate below freezing point. a. Dehumidification b. Defrosting c. Ice melting d. None of the above

b. Defrosting

A refrigeration system which can be used either to cool or to heat a given space, normally by exchanging the functions of the evaporator and the condenser. a. Heat pump b. Humidifier c. Dehumidifier d. None of the above

a. Heat pump

Air that flowing into a space through gaps around doors, windows, and others. a. Air intake b. Air changes c. Infiltration d. None of the above

c. Infiltration

The difference between dry bulb and wet bulb temperatures a. Wet bulb depression b. Relative humidity c. Dew point temperature d. None of the above

a. Wet bulb depression

The temperature at which a liquid is converted to solid state upon the removal of its latent heat of fusion. a. Cooling point b. Solid point c. Freezing point d. None of the above

c. Freezing point

To reduce the relative humidity of air, it is recommended to use a a. Humidifier b. Dehumidifier c. Psychrometer d. None of the above

b. Dehumidifier

In a domestic refrigerator, the condenser can be found ___ a. Inside the refrigerator cabinet b. Outside the refrigerator cabinet c. Beneath the freezer d. None of the above

b. Outside the refrigerator cabinet

Chilling injury of banana will occur at a temperature a. Below 27°C b. Below 14°C c. Below 5°C d. All of the above

c. Below 5°C

Freezers in refrigerator compartment are normally found at the upper section of the cabinet for the reason that a. It is easy to load product to the freezer b. Heat will efficiently be distributed to the refrigerator compartment c. it is easy to install the freezer in the cabinet d. None of the above

b. Heat will efficiently be distributed to the refrigerator compartment

Lowest temperature that is safe for storage of banana a. Below 14°C b. Below 5°C c. Below 0°C d. All of the above

a. Below 14°C

When a product is termed as frozen storage, it is a. Chilled and stored above freezing point b. The product is stored at 10°F to 50°F c. The product is stored between -10°F to 10°F d. All of the above

c. The product is stored between -10°F to 10°F

Another important factors in cold storage of perishable product are... a. Energy and power requirement inside the storage room b. Humidity and air motion inside the storage room c. Temperature and heat loss in the storage room d. None of the above

b. Humidity and air motion inside the storage room

The use of plastic polyethylene sheet as packaging material for cold storage is a. To provide heat insulating effect on the product b. To prevent moisture loss in the product c. To make the product attractive to the customer d. None of the above

b. To prevent moisture loss in the product

The purpose of refrigeration in storing perishable product is a. To improve the quality of the product b. To hasten ripening or maturity of product such as fruits and vegetable c. To arrest or retard the natural process of deterioration d. All of the above

c. To arrest or retard the natural process of deterioration

It is the process of exposing freshly-harvested product and carefully-prepared food to subzero temperatures and holding them at 32° C during storage period to maintain the quality of the products. a. Clod storage b. Quick freezing c. Sharp freezing d. All of the above

b. Quick freezing

If vegetables are stored at a temperature between 0°C to 30°C, the product is under a. Frozen storage b. Refrigerated storage c. All of the above d. None of the above

b. Refrigerated storage

Important factor that contributes in proper refrigeration of perishable crops is a. Constant temperature b. Free air circulation c. Control of relative humidity d. All of the above

d. All of the above

Freezing temperature for eggs a. 29 - 30°C b. 29 - 30°F c. 28°F d. None of the above

c. 28°F

It is the process of heating vegetables in steam or in boiling water to inactivate enzymes and reduce microbial population thereby prolonging storage at subfreezing temperature. a. Dehydration b. Blanching c. Drying d. None of the above

b. Blanching

Most favorable cold storage temperature for eggs a. 29 - 30°C b. 29 - 30°F c. 28°F d. None of the above

b. 29 - 30°F

Factors that change during cold storage of fish due to oxidation of fish oils and pigments particularly in more fatty species of fish. a. Color and flavor b. Color and texture c. Flavor and texture d. All of the above

a. Color and flavor

A process of retarding moisture and oxidation loss from the product during cold storage by providing a continuous film or coating that will adhere to the surface of the product. a. Blanching b. Thawing c. Glazing d. None of the above

c. Glazing

A freezer that operates at an air temperature of -30°F and below and a velocity of 500 to 100 fpm a. Sharp freezer b. Air-blast freezer c. Contact plate freezer d. All of the above

b. Air-blast freezer

A freezer used for fish product wherein the products are placed in shelves or in aluminum pans or plates covered by pipe coils or evaporates at a temperature of -20 to -29°C. a. Sharp freezer b. Air-blast freezer c. Contact plate freezer d. All of the above

a. Sharp freezer

Freezing point of milk a. -0.545°C b. -0.545°F c. 0.545°C d. None of the above

a. -0.545°C

A frozen product made of a pasteurized mixture of sugar, solid milk, stabilizer, food acid, and flavorings such as fruits, fruit juices or extract, and water. a. Ice cream b. Sherbet c. Frozen milk d. All of the above

b. Sherbet

Frozen poultry product gave only good for a period of a. 1 to 6 months b. 6 to 12 months c. 1 to 2 years d. All of the above

b. 6 to 12 months

Term used for the internal organs of poultry suitable for cold storage. a. Carcass b. Giblets c. Gills d. None of the above

b. Giblets

In order to minimize darkening of carcass of poultry meat, it is recommended that before cold storage poultry meat should be a. Slowly be frozen and undergo scalding process b. Frozen rapidly c. Undergo scalding process d. None of the above

b. Frozen rapidly

Tenderness of poultry meat can be maintained during cold storage by a. Storing it in aluminum foil b. Storing it in plastic net c. Storing it unpacked d. All of the above

a. Storing it in aluminum foil

PPT 6 Flashcards

(97 cards)