1
MEEN 464 Exam 1 Questions and Correct
Answers
What are the objectives of Lab 1?
Ans✅✅: To determine and compare the transient responses of
temperature measuring devices, to determine and compare the steady state
accuracies of temperature measuring devices, and to conduct uncertainty
analyses with experimental data
Which thermocouple will have the shortest time constant?
Ans✅✅: 30-gage T-type thermocouple with an exposed junction
Resistance temperature detectors measure the temperature by:
Ans✅✅: the change in electrical resistance in pure metals as a
function of temperature
Which of the following is not an objective of lab 2?
Ans✅✅: To determine the instantaneous, one dimensional temperature
distribution along a metallic rod subjected to a sudden change of the
boundary conditions
Consider a constant cross sectional area fin. Which fin dissipates the least
heat?
Ans✅✅: 0.5 inch diameter carbon steel fin
When designing a fin, carbon steel is typically better choice than aluminum.
Ans✅✅: False
The following graph shows temperature profiles along the axial direction of four
fins with same geometry. According to the following temperature profile, which
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,2
fin dissipates the most heat between the fin and the surrounding? Assume that
fin base temperature remains the same.
Ans✅✅: The horizontal line
Which of the following is not an objective of lab 3?
Ans✅✅: To determine the transient, one dimensional temperature
distribution along a constant rod subjected to a sudden change of the
boundary conditions
Which of the following has the largest thermal conductivity?
Ans✅✅: Copper
As mentioned in the video lecture, the heat transfer problem to find the
unknown thermal conductivities of the rods in our experiment can be
approximated as __________________
Ans✅✅: Perfect insulation of the rods, constant properties of the
material such as thermal conductivities, and 1-dimensional heat
conduction along the axis of the rods
Which of the following is not a correct statement on thermal conductivity?
Ans✅✅: Thermal conductivity of a material does not vary with
temperature
Consider a cylindrical rod with a constant cross-section area which is in contact
with an electrical heater at one end, and a heat sink at the other end. The
heater is held at 80 °C. and the rod is well insulated. The rod's steady state
temperature distribution and a linear interpolation are given on the plot below.
If the thermal conductivity of the rod is 205 W/(m-K), and the diameter of the
rod is 5.5cm, find the heat transfer rate (in watt) through the rod.
Ans✅✅: 14.6
Which of the following is not the objectives of lab 4?
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, 3
Ans✅✅: To find the unsteady temperature distribution along three
horizontal rods
Which of the following has the lowest thermal conductivity?
Ans✅✅: Stainless steel
Two collinear, short, metallic rods of the same diameter are in contact. the top
of the upper rod is electrically heated, and the bottom of the lower rod is cooled
with a fluid. The exposed surface of the rods are thermally insulated from the
surroundings. Which rods have the smallest thermal contact resistance?
Ans✅✅: Copper rods with thermal paste at the contact surface
For steady one-dimensional heat conduction in a solid medium, the rate of
heat transfer is directly proportional to the cross-sectional area for heat
transfer. The following figure shows the axial temperature distributions of two
collinear rods of equal diameter. The rods are arranged so that the faces are
contacting one another with a heat source at one end and a heat sink at the
opposite end. The rod is smooth stainless steel grade 316, with a thermal
conductivity equal to 10 W/mK
Ans✅✅: 0.2
The heat transfer problem to determine the thermal contact resistance at the
interface between two solid media in contact can be approximated as
______________
Ans✅✅: Perfect insulation of the rods, constant properties of the
materials such as thermal conductivity, and one dimensional heat
conduction along the axis of the rods.
Consider three thermocouples and match each probe with the curve that best
represents the transient response of temperature.
Ans✅✅: Sheathed 0.1 inch diameter T-type thermocouple will be in the
middle, the sheathed 0.2 inch diameter T-type thermocouple will take the
longest, and the 30-gauge T-type thermocouple with an exposed junction
will be the quickest.
Pretest - Stuvia US
MEEN 464 Exam 1 Questions and Correct
Answers
What are the objectives of Lab 1?
Ans✅✅: To determine and compare the transient responses of
temperature measuring devices, to determine and compare the steady state
accuracies of temperature measuring devices, and to conduct uncertainty
analyses with experimental data
Which thermocouple will have the shortest time constant?
Ans✅✅: 30-gage T-type thermocouple with an exposed junction
Resistance temperature detectors measure the temperature by:
Ans✅✅: the change in electrical resistance in pure metals as a
function of temperature
Which of the following is not an objective of lab 2?
Ans✅✅: To determine the instantaneous, one dimensional temperature
distribution along a metallic rod subjected to a sudden change of the
boundary conditions
Consider a constant cross sectional area fin. Which fin dissipates the least
heat?
Ans✅✅: 0.5 inch diameter carbon steel fin
When designing a fin, carbon steel is typically better choice than aluminum.
Ans✅✅: False
The following graph shows temperature profiles along the axial direction of four
fins with same geometry. According to the following temperature profile, which
Pretest - Stuvia US
,2
fin dissipates the most heat between the fin and the surrounding? Assume that
fin base temperature remains the same.
Ans✅✅: The horizontal line
Which of the following is not an objective of lab 3?
Ans✅✅: To determine the transient, one dimensional temperature
distribution along a constant rod subjected to a sudden change of the
boundary conditions
Which of the following has the largest thermal conductivity?
Ans✅✅: Copper
As mentioned in the video lecture, the heat transfer problem to find the
unknown thermal conductivities of the rods in our experiment can be
approximated as __________________
Ans✅✅: Perfect insulation of the rods, constant properties of the
material such as thermal conductivities, and 1-dimensional heat
conduction along the axis of the rods
Which of the following is not a correct statement on thermal conductivity?
Ans✅✅: Thermal conductivity of a material does not vary with
temperature
Consider a cylindrical rod with a constant cross-section area which is in contact
with an electrical heater at one end, and a heat sink at the other end. The
heater is held at 80 °C. and the rod is well insulated. The rod's steady state
temperature distribution and a linear interpolation are given on the plot below.
If the thermal conductivity of the rod is 205 W/(m-K), and the diameter of the
rod is 5.5cm, find the heat transfer rate (in watt) through the rod.
Ans✅✅: 14.6
Which of the following is not the objectives of lab 4?
Pretest - Stuvia US
, 3
Ans✅✅: To find the unsteady temperature distribution along three
horizontal rods
Which of the following has the lowest thermal conductivity?
Ans✅✅: Stainless steel
Two collinear, short, metallic rods of the same diameter are in contact. the top
of the upper rod is electrically heated, and the bottom of the lower rod is cooled
with a fluid. The exposed surface of the rods are thermally insulated from the
surroundings. Which rods have the smallest thermal contact resistance?
Ans✅✅: Copper rods with thermal paste at the contact surface
For steady one-dimensional heat conduction in a solid medium, the rate of
heat transfer is directly proportional to the cross-sectional area for heat
transfer. The following figure shows the axial temperature distributions of two
collinear rods of equal diameter. The rods are arranged so that the faces are
contacting one another with a heat source at one end and a heat sink at the
opposite end. The rod is smooth stainless steel grade 316, with a thermal
conductivity equal to 10 W/mK
Ans✅✅: 0.2
The heat transfer problem to determine the thermal contact resistance at the
interface between two solid media in contact can be approximated as
______________
Ans✅✅: Perfect insulation of the rods, constant properties of the
materials such as thermal conductivity, and one dimensional heat
conduction along the axis of the rods.
Consider three thermocouples and match each probe with the curve that best
represents the transient response of temperature.
Ans✅✅: Sheathed 0.1 inch diameter T-type thermocouple will be in the
middle, the sheathed 0.2 inch diameter T-type thermocouple will take the
longest, and the 30-gauge T-type thermocouple with an exposed junction
will be the quickest.
Pretest - Stuvia US
