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 2 of 21

Discover more Topics under Heat Transfer

Q11.
Reflectivity is defined as

a.

Fraction of total energy transmitted by the body

b.

Fraction of energy reflected by the body

c.

Fraction of total energy absorbed by the body

d.

Fraction of total energy absorbed and radiated by the body

Discuss
Answer: (b).Fraction of energy reflected by the body
Q12.
Of the radiant energy 350W/m² incident upon a surface 250W/m² is absorbed, 60W/m² is reflected and the remainder is transmitted through the surface. Workout the value for reflectivity for the surface material

a.

0.181

b.

0.171

c.

0.161

d.

0.151

Discuss
Answer: (b).0.171
Q13.
A thin metal plate of 4 cm diameter is suspended in atmospheric air whose temperature is 290 K. This plate attains a temperature of 295 K when one of its face receives radiant energy from a heat source at the rate of 2 W. If heat transfer coefficient on both surfaces of the plate is stated to be 87.5 W/m 2 K, workout the energy lost by reflection

a.

0.8 W

b.

0.3 W

c.

0.9 W

d.

0.10 W

Discuss
Answer: (c).0.9 W
Q14.
The value of reflectivity depends upon
(i) Body temperature

(ii) Wavelength of reflected radiation

(iii) Nature of surface of body

Identify the correct statement

a.

1 and 2

b.

2 and 3

c.

2 only

d.

1 and 3

Discuss
Answer: (d).1 and 3
Q15.
When a surface absorbs a certain fixed percentage of striking radiation the surface is called

a.

Grey body

b.

Black body

c.

White body

d.

Opaque body

Discuss
Answer: (a).Grey body
Q16.
Which one is true regarding gases?

a.

Reflectivity is unity

b.

Absorptivity is zero

c.

Reflectivity is zero

d.

Transmissivity is zero

Discuss
Answer: (c).Reflectivity is zero
Q17.
Thin glass plate is an example of

a.

Transparent body

b.

Opaque body

c.

Black body

d.

White body

Discuss
Answer: (a).Transparent body
Q18.
Radiant energy with an intensity of 800 W/m² strikes a flat plate normally. The absorptivity is thrice the reflectivity and twice the transmissivity. Determine the rate of reflection

a.

518.20 W/m²

b.

418.20 W/m²

c.

318.20 W/m²

d.

218.20 W/m²

Discuss
Answer: (d).218.20 W/m²
Q19.
Which one is true for opaque body?

a.

Transmissivity is zero

b.

Reflectivity is zero

c.

Absorptivity is zero

d.

Reflectivity is unity

Discuss
Answer: (a).Transmissivity is zero
Q20.
Energy strikes a vertical hemispherical plate with an intensity of 640 W/m². The absorptivity is thrice the transmissivity and twice the reflectivity. Determine the rate of transmission

a.

236.74 W/m²

b.

116.37 W/m²

c.

187.87 W/m²

d.

456.09 W/m²

Discuss
Answer: (b).116.37 W/m²
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