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.

A surface for which emissivity is constant at all temperatures and throughout the entire range of wavelength is called

A. Opaque
B. Grey
C. Specular
D. Diathermanous
Answer» C. Specular
Discussion
2.

Consider the previous problem, determine the maximum monochromatic emissive power of the sun’s surface

A. 4.908 * 10 13 W/m2
B. 5.908 * 10 13 W/m2
C. 6.908 * 10 13 W/m2
D. 7.908 * 10 13 W/m2
Answer» D. 7.908 * 10 13 W/m2
Discussion
3.

A small black body has a total emissive power of 4.5 k W/m2. In which range of the spectrum does this wavelength fall?

A. Thermal region
B. Cosmic region
C. Visible region
D. Infrared region
Answer» E.
Discussion
4.

A small body has a total emissive power of 4.5 kW/m2. Determine its surface temperature of maximum emission

A. 530.77 K
B. 345.65 K
C. 236.54 K
D. 367.8 K
Answer» B. 345.65 K
Discussion
5.

The relationship (Wavelength) MAX T = constant, between the temperature of a black body and the wavelength at which maximum value of monochromatic emissive power occurs is known as

A. Planck’s law
B. Kirchhoff’s law
C. Lambert’s law
D. Wein’s law
Answer» E.
Discussion
6.

A_SURFACE_FOR_WHICH_EMISSIVITY_IS_CONSTANT_AT_ALL_TEMPERATURES_AND_THROUGHOUT_THE_ENTIRE_RANGE_OF_WAVELENGTH_IS_CALLED?$

A. Opaque
B. Grey
C. Specular
D. Diathermanous
Answer» C. Specular
Discussion
7.

Four identical pieces of copper painted with different colors of paints were heated to the same temperature and then left in the environment to cool. Which of the following paint will give fast cooling?

A. White
B. Rough
C. Black
D. Shining
Answer» D. Shining
Discussion
8.

A furnace emits radiation at 2000 K. Treating it as a black body radiation, calculate the wavelength at which emission is maximum

A. 1.449 * 10<sup> -6</sup> m
B. 2.449 * 10<sup> -6</sup> m
C. 3.449 * 10<sup> -6</sup> m
D. 4.449 * 10<sup> -6</sup> m
Answer» B. 2.449 * 10<sup> -6</sup> m
Discussion
9.

Consider the previous problem, determine the maximum monochromatic emissive power of the sun’s surface$

A. 4.908 * 10<sup> 13</sup> W/m<sup>2</sup>
B. 5.908 * 10<sup> 13</sup> W/m<sup>2</sup>
C. 6.908 * 10<sup> 13</sup> W/m<sup>2</sup>
D. 7.908 * 10<sup> 13</sup> W/m<sup>2</sup>
Answer» D. 7.908 * 10<sup> 13</sup> W/m<sup>2</sup>
Discussion
10.

The sun emits maximum radiation of 0.52 micron meter. Assuming the sun to be a black body, Calculate the surface temperature of the sun

A. 2345 K
B. 5573 K
C. 9847 K
D. 6492 K
Answer» C. 9847 K
Discussion
11.

A small black body has a total emissive power of 4.5 k W/m2. In which range of the spectrum does this wavelength fall?

A. Thermal region
B. Cosmic region
C. Visible region
D. Infrared region
Answer» E.
Discussion
12.

A small body has a total emissive power of 4.5 kW/m2. Determine its surface temperature of maximum emission

A. 530.77 K
B. 345.65 K
C. 236.54 K
D. 367.8 K
Answer» B. 345.65 K
Discussion
13.

Two spheres A and B of same material have radius 1 m and 4 m, and temperatures 4000 K and 2000 K respectively. Then the energy radiated by sphere A is

A. Greater than that of sphere B
B. Less than that of sphere B
C. Equal to that of sphere B
D. Two times that of sphere B
Answer» D. Two times that of sphere B
Discussion
14.

A body at 500 K cools by radiating heat to ambient atmosphere maintained at 300 K. When the body has cooled to 400 K, the cooling rate as a percentage of original rate is about

A. 31.1
B. 41.5
C. 50.3
D. 80.4
Answer» B. 41.5
Discussion
15.

The relationship (Wavelength) MAX T = constant, between the temperature of a black body and the wavelength at which maximum value of monochromatic emissive power occurs is known as

A. Planck’s law
B. Kirchhoff’s law
C. Lambert’s law
D. Wein’s law
Answer» E.
Discussion