Transient Heat MCQs

Welcome to our comprehensive collection of Multiple Choice Questions (MCQs) on Transient Heat, a fundamental topic in the field of Heat Transfer. Whether you're preparing for competitive exams, honing your problem-solving skills, or simply looking to enhance your abilities in this field, our Transient Heat MCQs are designed to help you grasp the core concepts and excel in solving problems.

In this section, you'll find a wide range of Transient Heat mcq questions that explore various aspects of Transient Heat problems. Each MCQ is crafted to challenge your understanding of Transient Heat principles, enabling you to refine your problem-solving techniques. Whether you're a student aiming to ace Heat Transfer tests, a job seeker preparing for interviews, or someone simply interested in sharpening their skills, our Transient Heat MCQs are your pathway to success in mastering this essential Heat Transfer topic.

Note: Each of the following question comes with multiple answer choices. Select the most appropriate option and test your understanding of Transient Heat. You can click on an option to test your knowledge before viewing the solution for a MCQ. Happy learning!

So, are you ready to put your Transient Heat knowledge to the test? Let's get started with our carefully curated MCQs!

Transient Heat MCQs | Page 7 of 8

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Q61.
Which of the following dimensionless number gives an indication of the ratio of internal (conduction) resistance to the surface (convective) resistance?

a.

Biot number

b.

Fourier number

c.

Stanton number

d.

Nusselt number

Discuss
Answer: (a).Biot number
Q62.
Lumped parameter analysis for transient heat conduction is essentially valid for

a.

B I < 0.1

b.

1 < B I < 10

c.

0.1 < B I < 0.5

d.

It tends to infinity

Discuss
Answer: (a).B I < 0.1
Q63.
In the non-dimensional Biot number, the characteristics length is the ratio of

a.

Perimeter to surface area of solid

b.

Surface area to perimeter of solid

c.

Surface area to volume of solid

d.

Volume of solid to its surface area

Discuss
Answer: (d).Volume of solid to its surface area
Q64.
During heat treatment, cylindrical pieces of 25 mm diameter, 30 mm height and at 30 degree Celsius are placed in a furnace at 750 degree Celsius with convective coefficient 80 W/m² degree. Calculate the time required to heat the pieces to 600 degree Celsius. Assume the following property values
Density = 7850 kg /m³
Specific heat = 480 J/kg K
Conductivity = 40 W/m degree

a.

226 sec

b.

326 sec

c.

426 sec

d.

526 sec

Discuss
Answer: (b).326 sec
Q65.
The quantity h L C/k is known as

a.

Biot number

b.

Fourier number

c.

Stanton number

d.

Nusselt number

Discuss
Answer: (a).Biot number
Q66.
For a plat plate (thickness ฮด, breadth b and height h) the heat exchange occurs from both the sides. The characteristics length is equal to

a.

ฮด/4

b.

ฮด/3

c.

ฮด/2

d.

ฮด

Discuss
Answer: (c).ฮด/2
Q67.
Fourier number is given by

a.

ฮฑ T/LC²

b.

2 ฮฑ T/LC²

c.

3 ฮฑ T/LC²

d.

4 ฮฑ T/LC²

Discuss
Answer: (a).ฮฑ T/LC²
Q68.
Identify the correct relation between Biot number and Fourier number

a.

4 b T = B I F 0

b.

2 b T = B I F 0

c.

3 b T = B I F 0

d.

b T = B I F 0

Discuss
Answer: (d).b T = B I F 0
Q69.
A water line is buried underground in dry soil that has an assumed initial temperature of 4.5 degree Celsius. The pipe may have no flow through it for long period of time, yet it will not be drained in order that no freezing occurs, the pipe must be kept at a temperature not lower than 0 degree Celsius. The pipe is to be designed for a 30 hour period at the beginning of which the soil surface temperature suddenly drops to โ€“ 17 degree Celsius. Workout the minimum earth covering needed above the water pipe so as to prevent the possibility of freezing during 36 hour cold spell. The soil in which the pipe is buried has the following properties

Density = 640 kg/m³
Specific heat = 1843J/kg degree
Thermal conductivity = 0.345 W/m degree

a.

0.25 m

b.

0.35 m

c.

0.45 m

d.

0.55 m

Discuss
Answer: (b).0.35 m
Q70.
At a certain time instant, the temperature distribution in a long cylindrical fire tube can be represented approximately by the relation

T = 650 + 800 r โ€“ 4250 r²

Where temperature t is in degree Celsius and radius r is in meter. Find the rate of heat flow such that the tube measures: inside radius 25 cm, outside radius 40 cm and length 1.5 m.

For the tube material

K = 5.5 W/m K

ฮฑ = 0.004 m²/hr

a.

3.672 * 10 8 W

b.

3.672 * 10 2 W

c.

3.672 * 10 5 W

d.

โ€“ 3.672 * 10 5 W

Discuss
Answer: (d).โ€“ 3.672 * 10 5 W
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