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 7 of 21

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Q61.
The solid angle is defined by a region by the rays of a sphere, and is measured as

a.

An/r²

b.

An/r

c.

An/r³

d.

An/rโด

Discuss
Answer: (a).An/r²
Q62.
The plane angle is defined by a region by the rays of a circle, and is measured as

a.

3 L/ r

b.

2 L/ r

c.

L/ r

d.

4 L / r

Discuss
Answer: (c).L/ r
Q63.
When the incident surface is a sphere, the projection of surface normal to the line of propagation is the silhouette disk of the sphere which is a circle of the diameter of

a.

Parabola

b.

Sphere

c.

Triangle

d.

Hyperbola

Discuss
Answer: (b).Sphere
Q64.
If I n denotes the normal intensity and I ฮฑ represents the intensity at angle ฮฑ, then

a.

I ฮฑ = 2 I n cos ฮฑ

b.

I ฮฑ = 3 I n cos ฮฑ

c.

I ฮฑ = 4 I n cos ฮฑ

d.

I ฮฑ = I n cos ฮฑ

Discuss
Answer: (d).I ฮฑ = I n cos ฮฑ
Q65.
The intensity of normal radiation In is how much times the emissive power?

a.

1/ฯ€

b.

2/ ฯ€

c.

3/ ฯ€

d.

4/ ฯ€

Discuss
Answer: (a).1/ฯ€
Q66.
A small surface emits diffusively, and measurements indicate that the total intensity associated with emission in the normal direction I n = 6500 W/square m sr. The emitted radiation is intercepted by three surfaces. Mark calculations for intensity associated with emission

a.

3500 W/m² sr

b.

4500 W/m² sr

c.

5500 W/m² sr

d.

6500 W/m² sr

Discuss
Answer: (d).6500 W/m² sr
Q67.
Consider a deep-space probe constructed as 1 m diameter polished aluminum sphere. Estimate the equilibrium temperature that the probe reaches if the solar energy received is 300 W/m². For solar radiation, absorptivity of aluminum is 0.3 and the average emissivity appropriate for aluminum at low temperature is 0.04

a.

415.67 K

b.

315.67 K

c.

215.67 K

d.

115.67 K

Discuss
Answer: (b).315.67 K
Q68.
The total emissive power of the emitter with area d A and temperature T is given by

a.

E = 2 ฯƒ Tโด d A

b.

E = 3 ฯƒ Tโด d A

c.

E = ฯƒ Tโด d A

d.

E = ½ ฯƒ Tโด d A

Discuss
Answer: (c).E = ฯƒ Tโด d A
Q69.
A black body of 0.2 m² area has an effective temperature of 800 K. Calculate the intensity of normal radiations

a.

1234.65 W/m² sr

b.

7396.28 W/m² sr

c.

3476.74 W/m² sr

d.

8739.43 W/m² sr

Discuss
Answer: (b).7396.28 W/m² sr
Q70.
The energy radiated out decreases with increases in ฮฑ and becomes zero at an angle of

a.

45

b.

30

c.

0

d.

90

Discuss
Answer: (d).90
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