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 3 of 8

Discover more Topics under Heat Transfer

Q21.
A cylindrical stainless steel (k = 25 W/m K) ingot, 10 cm in diameter and 25 cm long, passes through a heat treatment furnace which is 5 meter in length. The initial ingot temperature is 90 degree Celsius, the furnace gas is at 1260 degree Celsius and the combined radiant and convective surface coefficient is 100 W/m² K. Determine the maximum speed with which the ingot moves through the furnace if it must attain 830 degree Celsius temperature. Take thermal diffusivity as 0.45 * 10¯⁵ m²/s

a.

. 000116 m/s

b.

.000216 m/s

c.

. 000316 m/s

d.

. 000416 m/s

Discuss
Answer: (b)..000216 m/s
Q22.
The curve for unsteady state cooling or heating of bodies is

a.

Hyperbolic curve asymptotic both to time and temperature axis

b.

Exponential curve asymptotic both to time and temperature axis

c.

Parabolic curve asymptotic to time axis

d.

Exponential curve asymptotic to time axis

Discuss
Answer: (d).Exponential curve asymptotic to time axis
Q23.
What is the wavelength band for TV rays?

a.

1 * 10³ to 34 * 10¹⁰ micron meter

b.

1 * 10³ to 2 * 10 ¹⁰ micron meter

c.

1 * 10³ to 3 * 10¹⁰ micron meter

d.

1 * 10³ to 56 * 10¹⁰ micron meter

Discuss
Answer: (b).1 * 10³ to 2 * 10 ¹⁰ micron meter
Q24.
Diagram shows transient heat conduction in an infinite plane wall. Identify the correct boundary condition in transient heat conduction in solids with finite conduction.

a.

t = t i at T = 0

b.

d t /d x = 1 at x = 0

c.

d t /d x = infinity at x = 1

d.

d t / d x = infinity at x = 0

Discuss
Answer: (a).t = t i at T = 0
Q25.
Let there is some conduction resistance, then temperature becomes a function of
(i) Biot number
(ii)Fourier number
(iii) Dimensionless parameter
Identify the correct statement

a.

1 and 2

b.

2 and 3

c.

1 and 3

d.

1, 2 and 3

Discuss
Answer: (d).1, 2 and 3
Q26.
A large steel plate 50 mm thick is initially at a uniform temperature of 425 degree Celsius. It is suddenly exposed on both sides to an environment with convective coefficient 285 W/m² K and temperature 65 degree Celsius. Determine the center line temperature.
For steel, thermal conductivity = 42.5 W/m K and thermal diffusivity = 0.043 m²/hr

a.

261 degree Celsius

b.

271 degree Celsius

c.

281 degree Celsius

d.

291 degree Celsius

Discuss
Answer: (c).281 degree Celsius
Q27.
“When Biot number exceeds 0.1 but is less than 100, use is made of Heislers charts for the solution of transient heat conduction”. Choose the correct answer

a.

True

b.

False

c.

May be

d.

Can't say

Discuss
Answer: (a).True
Q28.
An egg with mean diameter of 4 cm and initially at 25 degree Celsius is placed in an open boiling water container for 4 minutes and found to be boiled at a particular level. For how long should a similar egg boil at the same level, when refrigerator temperature is 5 degree Celsius? Use lumped parameter theory and assume following properties of egg

k = 12 W/m K

h = 125 W/m² K

c = 2 k J/kg K

p = 1250 kg/m³

a.

251.49 seconds

b.

261.49 seconds

c.

271.49 seconds

d.

281.49 seconds

Discuss
Answer: (c).271.49 seconds
Q29.
A person is found dead at 5 pm in a room whose temperature is 20 degree Celsius. The temperature of body is measured to be 25 degree Celsius, when found and heat transfer coefficient is estimated to be 8 W/m² K. Modeling the body as a 30 cm diameter, 1.7 cm long cylinder. Estimate the time of death of person.

a.

13.55 seconds

b.

12.55 seconds

c.

11.55 seconds

d.

10.55 seconds

Discuss
Answer: (d).10.55 seconds
Q30.
The following data pertains to the junction of a thermocouple wire used to measure the temperature of the gas stream.

Density = 8500 kg/m³, specific heat = 325 J/kg K, thermal conductivity = 40 W/m K and the heat transfer coefficient between the junction and gas = 215 W/m² K.

If thermocouple junction can be approximated as 1 mm diameter sphere, determine how long it will take for the thermocouple to read 99% of the initial temperature difference.

a.

9.86 seconds

b.

8.86 seconds

c.

7.86 seconds

d.

6.86 seconds

Discuss
Answer: (a).9.86 seconds
Page 3 of 8