Questions and answers for exam Preparation

MCQs

Heat Radiation, Thermal Properties Of Matter, Dual Nature Of Matter

Total Questions : 247 | Page 19 of 25 pages

Question 181. Which quantity can be neglected for gases?

Transmissivity
Reflectivity
Absorptivity
None can be neglected

Discuss Question

Answer: Option B. -> Reflectivity
Answer: (b).Reflectivity

Question 182. Radiation heat transfer is characterized by

Due to bulk fluid motion, there is transport of energy
Thermal energy transfer as vibrational energy in the lattice structure of the material
Movement of discrete packets of energy as electromagnetic waves
There is circulation of fluid by buoyancy effects

Discuss Question

Answer: Option C. -> Movement of discrete packets of energy as electromagnetic waves
Answer: (c).Movement of discrete packets of energy as electromagnetic waves

Question 183. Radiation exchange occurs in

Solid
Vacuum
Liquid
Gas

Discuss Question

Answer: Option B. -> Vacuum
Answer: (b).Vacuum

Question 184. Which is true regarding radiation?

Radiation travels only in medium
Radiation travels without any medium
Radiation travels in medium but sometimes without medium
Radiation travels in medium or without medium

Discuss Question

Answer: Option D. -> Radiation travels in medium or without medium
Answer: (d).Radiation travels in medium or without medium

Question 185. Thermal radiations occur in the portion of electromagnetic spectrum between the wavelengths

10¯² to 10¯⁴ micron
10¯¹ to 10¯² micron
0.1 to 10² micron
10¯² micron onwards

Discuss Question

Answer: Option C. -> 0.1 to 10² micron
Answer: (c).0.1 to 10² micron

Question 186. The electromagnetic waves are emitted as a result of
(i) Vibrational movement
(ii) Rotational movement
(iii)Atomic or sub-atomic particles comprising the matter
Identify the correct statement

1 and 2
2 and 3
1 and 3
1, 2 and 3

Discuss Question

Answer: Option D. -> 1, 2 and 3
Answer: (d).1, 2 and 3

Question 187. Energy released by a radiating surface is not continuous but is in the form of successive and separate packets of energy called

Photons
Protons
Electrons
Neutrons

Discuss Question

Answer: Option A. -> Photons
Answer: (a).Photons

Question 188. 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?

Thermal region
Cosmic region
Visible region
Infrared region

Discuss Question

Answer: Option D. -> Infrared region
Answer: (d).Infrared region

Question 189. 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