PPT 6 Flashcards
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
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
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
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
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
One British thermal unit is equal
to _____
a. 1055 J
b. 1505 J
c. 1550 J
d. None of the above
a. 1055 J
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
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
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
A good insulator for kiln dryer.
a. Rice husk
b. Brick
c. Concrete
d. None of the abov
b. Brick
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
An example of a good insulating
material at high temperature.
a. Iron
b. Wood
c. Asbestos
d. All of the above
c. Asbestos
Which of the following has low
thermal conductivity?
a. Building brick
b. Asbestos
c. Firebrick
d. Concrete
b. Asbestos
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
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
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
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
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
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
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
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
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
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
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
The equation for heat transfer by
radiation for gray bodies is
a. Qr = AT4
b. Qr = εAT4
c. Qr = εAT4
d. None of the above
b. Qr = εAT4
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
