Explore topic-wise MCQs in Heat Transfer.

This section includes 15 Mcqs, each offering curated multiple-choice questions to sharpen your Heat Transfer knowledge and support exam preparation. Choose a topic below to get started.

1.

Electromagnetic waves strikes a hot body maintained at 900 degree Celsius which has a reflectivity of 0.66 and a transmissivity of 0.022. Let the absorbed flux be 60 W/m2. Determine the rate of incident flux

A. 168.67 W/m2
B. 178.67 W/m2
C. 188.67 W/m2
D. 198.67 W/m2
Answer» D. 198.67 W/m2
Discussion
2.

Absorptivity of a body is equal to its emissivity

A. Under thermal equilibrium conditions
B. For a polished surface
C. At one particular temperature
D. At shorter wavelengths
Answer» B. For a polished surface
Discussion
3.

Let 220 W/m2 of radiant energy is absorbed by a convex surface, 90 W/m2 is reflected and 40 W/m2 is transmitted through it. What is the value of absorptivity?

A. 0.72
B. 0.62
C. 0.52
D. 0.42
Answer» C. 0.52
Discussion
4.

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 absorption

A. 449.12 W/m2
B. 349.12 W/m2
C. 249.12 W/m2
D. 149.12 W/m2
Answer» C. 249.12 W/m2
Discussion
5.

The absorptivity of a surface depends upon(i) Direction of reflected radiation(ii) Temperature of the surface(iii) CompositionIdentify the correct statements

A. i, ii and iii
B. i and iii
C. ii only
D. ii and iii
Answer» E.
Discussion
6.

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
Answer» C. 187.87 W/m2
Discussion
7.

ABSORPTIVITY_OF_A_BODY_IS_EQUAL_TO_ITS_EMISSIVITY?$

A. Under thermal equilibrium conditions
B. For a polished surface
C. At one particular temperature
D. At shorter wavelengths
Answer» B. For a polished surface
Discussion
8.

Electromagnetic_waves_strikes_a_hot_body_maintained_at_900_degree_Celsius_which_has_a_reflectivity_of_0.66_and_a_transmissivity_of_0.022._Let_the_absorbed_flux_be_60_W/m2._Determine_the_rate_of_incident_flux$

A. 168.67 W/m<sup>2</sup>
B. 178.67 W/m<sup>2</sup>
C. 188.67 W/m<sup>2</sup>
D. 198.67 W/m<sup>2</sup>
Answer» D. 198.67 W/m<sup>2</sup>
Discussion
9.

Which quantity can be neglected for gases?

A. Transmissivity
B. Reflectivity
C. Absorptivity
D. None can be neglected
Answer» C. Absorptivity
Discussion
10.

For a grey surface

A. Reflectivity equals emissivity
B. Emissivity equals transmissivity
C. Absorptivity equals reflectivity
D. Emissivity is constant
Answer» E.
Discussion
11.

Let 220 W/m2 of radiant energy is absorbed by a convex surface, 90 W/m2 is reflected and 40 W/m2 is transmitted through it. What is the value of absorptivity?

A. 0.72
B. 0.62
C. 0.52
D. 0.42
Answer» C. 0.52
Discussion
12.

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 absorption

A. 449.12 W/m<sup>2</sup>
B. 349.12 W/m<sup>2</sup>
C. 249.12 W/m<sup>2</sup>
D. 149.12 W/m<sup>2</sup>
Answer» C. 249.12 W/m<sup>2</sup>
Discussion
13.

A body that reflects all the incident thermal radiations is called a

A. Opaque body
B. Gases
C. Black body
D. Specular body
Answer» E.
Discussion
14.

What is the absorptivity of the gray body?

A. Below unity
B. Unity
C. 2
D. 2.5
Answer» B. Unity
Discussion
15.

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/m<sup>2</sup>
B. 116.37 W/m<sup>2</sup>
C. 187.87 W/m<sup>2</sup>
D. 456.09 W/m<sup>2</sup>
Answer» C. 187.87 W/m<sup>2</sup>
Discussion