Heat Radiation MCQs

Welcome to our comprehensive collection of Multiple Choice Questions (MCQs) on Heat Radiation, 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 Heat Radiation 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 Heat Radiation mcq questions that explore various aspects of Heat Radiation problems. Each MCQ is crafted to challenge your understanding of Heat Radiation 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 Heat Radiation 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 Heat Radiation. 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 Heat Radiation knowledge to the test? Let's get started with our carefully curated MCQs!

Heat Radiation MCQs | Page 15 of 21

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Q141.
The total radiant energy incident upon a surface per unit time per unit area is known as

a.

Shape factor

b.

Radiosity

c.

Radiation

d.

Irradiation

Discuss
Answer: (d).Irradiation
Q142.
Which one of the following is true for opaque non-black surface?

a.

J = E +2 p G

b.

J = E + p G

c.

J = 2 E + p G

d.

J = ½ E + p G

Discuss
Answer: (b).J = E + p G
Q143.
A radiation shield should

a.

Have high transmissivity

b.

Absorb all the radiations

c.

Have high reflexive power

d.

Partly absorb and partly transmit the incident radiation

Discuss
Answer: (c).Have high reflexive power
Q144.
Radiation shield are used between the emitting surfaces such that

a.

To reduce overall heat transfer

b.

To increase overall heat transfer

c.

To increase density

d.

To reduce density

Discuss
Answer: (a).To reduce overall heat transfer
Q145.
Which of the following can be used as a radiating shield?

a.

Carbon

b.

Thin sheets of aluminum

c.

Iron

d.

Gold

Discuss
Answer: (b).Thin sheets of aluminum
Q146.
Determine the net radiant heat exchange per m 2 area for two infinite parallel plates held at temperature of 800 K and 500 K. Take emissivity as 0.6 for the hot plate and 0.4 for the cold plate

a.

6200 W/m²

b.

7200 W/m²

c.

8200 W/m²

d.

9200 W/m²

Discuss
Answer: (a).6200 W/m²
Q147.
Two parallel square plates, each 4 m² area, are large compared to a gap of 5 mm separating them. One plate has a temperature of 800 K and surface emissivity of 0.6, while the other has a temperature of 300 K and surface emissivity of 0.9. Find the net energy exchange by radiations between the plates

a.

61.176 k W

b.

51.176 k W

c.

41.176 k W

d.

31.176 k W

Discuss
Answer: (b).51.176 k W
Q148.
The furnace of a boiler is laid from fire clay brick with outside lagging from the plate steel, the distance between the two is quite small compared with the size of the furnace. The brick setting is at an average temperature of 365 K whilst the steel lagging is at 290 K. Calculate the radiant heat flux. Assume the following emissivity values

For brick = 0.85
For steel = 0.65

a.

352.9 W/m²

b.

452.9 W/m²

c.

552.9 W/m²

d.

652.9 W/m²

Discuss
Answer: (a).352.9 W/m²
Q149.
Two black discs each of diameter 50 cm are placed parallel to each other concentrically at a distance of one meter. The discs are maintained at 1000 K and 500 K. Calculate the heat flow between the discs when no other surface is present

a.

317.27 W

b.

417.27 W

c.

517.27 W

d.

617.27 W

Discuss
Answer: (b).417.27 W
Q150.
Two black discs each of diameter 50 cm are placed parallel to each other concentrically at a distance of one meter. The discs are maintained at 1000 K and 500 K. Calculate the heat flow between the discs when the disks are connected by a cylindrical black no-flux surface

a.

2417.68 W

b.

3417.68 W

c.

4417.68 W

d.

5417.68 W

Discuss
Answer: (d).5417.68 W
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