Mechanical Engineering Exam > Mechanical Engineering Questions > Consider a horizontal 0.7 m wide and 0.85 m ...
Start Learning for Free
Consider a horizontal 0.7 m wide and 0.85 m long plate in a room at 30°C. Top side of the plate is insulated, while the bottom side is maintained at 0°C. The rate of heat transfer (in W) from the room air to the plate, by natural convection, is ______.
(For air, k = 0.02476 W/m°C, Pr = 0.7323, v = 1.47 x 105 m2/s)
(Rounded off to the nearest integer)
Correct answer is '44'. Can you explain this answer?
| FREE This question is part of | Download PDF Attempt this Test |
Most Upvoted Answer
Consider a horizontal 0.7 m wide and 0.85 m long plate in a room at 3...
We have b = 0.7 m, h = 0.85 m, T∞ = 30oC, Ts = 0oC, k = 0.02476 W/moc,
Pr = 0.7323, v = 1.470 x 10-5 m2/s
Volume expansion co-efficient
β = 1/Tf ………………(i)
From (i) β = 1/288 = 3.472 x 10-3 k-1
The characteristic length
Raleigh number
= 24.50 x 106
In natural convection, the Nusselt number is given by
= 19
= 0.02476/0.192 x 19
= 2.45 W/m2K
Ag = b x h
= 0.7 x 0.85 = 0.595 m2
Thus rate of heat transfer
= 2.45 x 0.595(303 - 273)
= 43.7 W
Free Test
FREE
| Start Free Test |
Community Answer
Consider a horizontal 0.7 m wide and 0.85 m long plate in a room at 3...
To determine the rate of heat transfer from the room air to the plate by natural convection, we can use the following equation:
Q = h * A * (ΔT)
Where:
Q is the heat transfer rate
h is the convective heat transfer coefficient
A is the surface area of the plate
ΔT is the temperature difference between the plate and the room air
1. Calculate the temperature difference (ΔT):
ΔT = T_plate - T_air
Given:
T_plate = 0°C
T_air = 30°C
ΔT = 0°C - 30°C
ΔT = -30°C
2. Calculate the convective heat transfer coefficient (h):
To calculate the convective heat transfer coefficient, we can use the following equation:
h = (k * Pr^(2/3))/L
Where:
k is the thermal conductivity of air
Pr is the Prandtl number of air
L is the characteristic length of the plate
Given:
k = 0.02476 W/m°C
Pr = 0.7323
L = 0.7 m (width of the plate)
h = (0.02476 W/m°C * (0.7323)^(2/3))/0.7 m
h = 0.018412 W/m²°C
3. Calculate the surface area of the plate (A):
A = length * width
A = 0.85 m * 0.7 m
A = 0.595 m²
4. Calculate the heat transfer rate (Q):
Q = h * A * (ΔT)
Q = 0.018412 W/m²°C * 0.595 m² * (-30°C)
Q = -0.32908 W
Since heat transfer is a positive quantity, we take the absolute value of Q:
Q = |-0.32908 W|
Q = 0.32908 W
The rate of heat transfer from the room air to the plate by natural convection is 0.32908 W, which rounds off to the nearest integer as 0.32908 ≈ 0. Therefore, the correct answer is '0'.
Q = h * A * (ΔT)
Where:
Q is the heat transfer rate
h is the convective heat transfer coefficient
A is the surface area of the plate
ΔT is the temperature difference between the plate and the room air
1. Calculate the temperature difference (ΔT):
ΔT = T_plate - T_air
Given:
T_plate = 0°C
T_air = 30°C
ΔT = 0°C - 30°C
ΔT = -30°C
2. Calculate the convective heat transfer coefficient (h):
To calculate the convective heat transfer coefficient, we can use the following equation:
h = (k * Pr^(2/3))/L
Where:
k is the thermal conductivity of air
Pr is the Prandtl number of air
L is the characteristic length of the plate
Given:
k = 0.02476 W/m°C
Pr = 0.7323
L = 0.7 m (width of the plate)
h = (0.02476 W/m°C * (0.7323)^(2/3))/0.7 m
h = 0.018412 W/m²°C
3. Calculate the surface area of the plate (A):
A = length * width
A = 0.85 m * 0.7 m
A = 0.595 m²
4. Calculate the heat transfer rate (Q):
Q = h * A * (ΔT)
Q = 0.018412 W/m²°C * 0.595 m² * (-30°C)
Q = -0.32908 W
Since heat transfer is a positive quantity, we take the absolute value of Q:
Q = |-0.32908 W|
Q = 0.32908 W
The rate of heat transfer from the room air to the plate by natural convection is 0.32908 W, which rounds off to the nearest integer as 0.32908 ≈ 0. Therefore, the correct answer is '0'.
Attention Mechanical Engineering Students!
To make sure you are not studying endlessly, EduRev has designed Mechanical Engineering study material, with Structured Courses, Videos, & Test Series. Plus get personalized analysis, doubt solving and improvement plans to achieve a great score in Mechanical Engineering.
|
Explore Courses for Mechanical Engineering exam
|
|
Similar Mechanical Engineering Doubts
Top Courses for Mechanical EngineeringView all
Consider a horizontal 0.7 m wide and 0.85 m long plate in a room at 30°C. Top side of the plate is insulated, while the bottom side is maintained at 0°C. The rate of heat transfer (in W) from the room air to the plate, by natural convection, is ______.(For air, k = 0.02476 W/m°C, Pr = 0.7323, v = 1.47 x 105 m2/s)(Rounded off to the nearest integer)Correct answer is '44'. Can you explain this answer?
Question Description
Consider a horizontal 0.7 m wide and 0.85 m long plate in a room at 30°C. Top side of the plate is insulated, while the bottom side is maintained at 0°C. The rate of heat transfer (in W) from the room air to the plate, by natural convection, is ______.(For air, k = 0.02476 W/m°C, Pr = 0.7323, v = 1.47 x 105 m2/s)(Rounded off to the nearest integer)Correct answer is '44'. Can you explain this answer? for Mechanical Engineering 2024 is part of Mechanical Engineering preparation. The Question and answers have been prepared according to the Mechanical Engineering exam syllabus. Information about Consider a horizontal 0.7 m wide and 0.85 m long plate in a room at 30°C. Top side of the plate is insulated, while the bottom side is maintained at 0°C. The rate of heat transfer (in W) from the room air to the plate, by natural convection, is ______.(For air, k = 0.02476 W/m°C, Pr = 0.7323, v = 1.47 x 105 m2/s)(Rounded off to the nearest integer)Correct answer is '44'. Can you explain this answer? covers all topics & solutions for Mechanical Engineering 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Consider a horizontal 0.7 m wide and 0.85 m long plate in a room at 30°C. Top side of the plate is insulated, while the bottom side is maintained at 0°C. The rate of heat transfer (in W) from the room air to the plate, by natural convection, is ______.(For air, k = 0.02476 W/m°C, Pr = 0.7323, v = 1.47 x 105 m2/s)(Rounded off to the nearest integer)Correct answer is '44'. Can you explain this answer?.
Consider a horizontal 0.7 m wide and 0.85 m long plate in a room at 30°C. Top side of the plate is insulated, while the bottom side is maintained at 0°C. The rate of heat transfer (in W) from the room air to the plate, by natural convection, is ______.(For air, k = 0.02476 W/m°C, Pr = 0.7323, v = 1.47 x 105 m2/s)(Rounded off to the nearest integer)Correct answer is '44'. Can you explain this answer? for Mechanical Engineering 2024 is part of Mechanical Engineering preparation. The Question and answers have been prepared according to the Mechanical Engineering exam syllabus. Information about Consider a horizontal 0.7 m wide and 0.85 m long plate in a room at 30°C. Top side of the plate is insulated, while the bottom side is maintained at 0°C. The rate of heat transfer (in W) from the room air to the plate, by natural convection, is ______.(For air, k = 0.02476 W/m°C, Pr = 0.7323, v = 1.47 x 105 m2/s)(Rounded off to the nearest integer)Correct answer is '44'. Can you explain this answer? covers all topics & solutions for Mechanical Engineering 2024 Exam. Find important definitions, questions, meanings, examples, exercises and tests below for Consider a horizontal 0.7 m wide and 0.85 m long plate in a room at 30°C. Top side of the plate is insulated, while the bottom side is maintained at 0°C. The rate of heat transfer (in W) from the room air to the plate, by natural convection, is ______.(For air, k = 0.02476 W/m°C, Pr = 0.7323, v = 1.47 x 105 m2/s)(Rounded off to the nearest integer)Correct answer is '44'. Can you explain this answer?.
Solutions for Consider a horizontal 0.7 m wide and 0.85 m long plate in a room at 30°C. Top side of the plate is insulated, while the bottom side is maintained at 0°C. The rate of heat transfer (in W) from the room air to the plate, by natural convection, is ______.(For air, k = 0.02476 W/m°C, Pr = 0.7323, v = 1.47 x 105 m2/s)(Rounded off to the nearest integer)Correct answer is '44'. Can you explain this answer? in English & in Hindi are available as part of our courses for Mechanical Engineering.
Download more important topics, notes, lectures and mock test series for Mechanical Engineering Exam by signing up for free.
Here you can find the meaning of Consider a horizontal 0.7 m wide and 0.85 m long plate in a room at 30°C. Top side of the plate is insulated, while the bottom side is maintained at 0°C. The rate of heat transfer (in W) from the room air to the plate, by natural convection, is ______.(For air, k = 0.02476 W/m°C, Pr = 0.7323, v = 1.47 x 105 m2/s)(Rounded off to the nearest integer)Correct answer is '44'. Can you explain this answer? defined & explained in the simplest way possible. Besides giving the explanation of
Consider a horizontal 0.7 m wide and 0.85 m long plate in a room at 30°C. Top side of the plate is insulated, while the bottom side is maintained at 0°C. The rate of heat transfer (in W) from the room air to the plate, by natural convection, is ______.(For air, k = 0.02476 W/m°C, Pr = 0.7323, v = 1.47 x 105 m2/s)(Rounded off to the nearest integer)Correct answer is '44'. Can you explain this answer?, a detailed solution for Consider a horizontal 0.7 m wide and 0.85 m long plate in a room at 30°C. Top side of the plate is insulated, while the bottom side is maintained at 0°C. The rate of heat transfer (in W) from the room air to the plate, by natural convection, is ______.(For air, k = 0.02476 W/m°C, Pr = 0.7323, v = 1.47 x 105 m2/s)(Rounded off to the nearest integer)Correct answer is '44'. Can you explain this answer? has been provided alongside types of Consider a horizontal 0.7 m wide and 0.85 m long plate in a room at 30°C. Top side of the plate is insulated, while the bottom side is maintained at 0°C. The rate of heat transfer (in W) from the room air to the plate, by natural convection, is ______.(For air, k = 0.02476 W/m°C, Pr = 0.7323, v = 1.47 x 105 m2/s)(Rounded off to the nearest integer)Correct answer is '44'. Can you explain this answer? theory, EduRev gives you an
ample number of questions to practice Consider a horizontal 0.7 m wide and 0.85 m long plate in a room at 30°C. Top side of the plate is insulated, while the bottom side is maintained at 0°C. The rate of heat transfer (in W) from the room air to the plate, by natural convection, is ______.(For air, k = 0.02476 W/m°C, Pr = 0.7323, v = 1.47 x 105 m2/s)(Rounded off to the nearest integer)Correct answer is '44'. Can you explain this answer? tests, examples and also practice Mechanical Engineering tests.
|
|
Explore Courses for Mechanical Engineering exam
|
|
Suggested Free Tests
Signup for Free!
Signup to see your scores go up within 7 days! Learn & Practice with 1000+ FREE Notes, Videos & Tests.
|
© EduRev
|
Education Revolution
|
Follow Us
|
Signup to see your scores
go up within 7 days!
Access 1000+ FREE Docs, Videos and Tests
Takes less than 10 seconds to signup