31. A body at a given temperature will emit radiation of a whole range of wavelengths and not a single wavelength. The statement is related to:

(a) Wavelength and Frequency
(b) The Origins of Radiant Energy
(c) The Distribution of Radiant Energy
(d) The Emissive Power

Answer: (c)

32. Which of the following laws are the laws of black-body radiation?
(a) Planck’s law, Wien’s law and Fourier’s law
(b) Planck’s law, Fourier’s law and Stefan-Boltzmann law
(c) Planck’s law, Wien’s law and Stefan-Boltzmann law
(d) Fourier’s law, Wien’s law and Stefan-Boltzmann law

Answer: (c)

33. In diffusion, when vapour pressure of water in air equals that of the liquid, the air is saturated and vaporization:
(a) Persists
(b) Initiates
(c) Ceases
(d) Preserves

Answer: (c)

34. A Newtonian fluid which is in fully developed flow has the actual velocity distribution at the entrance to the heated section and the theoretical distribution throughout the tube. They both are:
(a) Parabolic
(b) Circular
(c) Linear
(d) Elliptic

Answer: (a)

35. If the liquid wets the surface, the condensate flows on the surface in the form of a film, and the process is called:
(a) Drop condensation
(b) Film condensation
(c) Film flow condensation
(d) Laminar film condensation

Answer: (b)

36. During the re-entry of a space vehicle into the earth’s atmosphere a large quantity of heat is generated at the surface due to air friction, which is very rapidly removed by a process called:
(a) Ablation
(b) Abolition
(c) Abrasion
(d) Aeration

Answer: (a)

37. The transport of one constituent from a region of higher concentration to that of a lower concentration is known as:
(a) Mass Diffusion
(b) Mass Transition
(c) Mass Transfer
(d) Heat Transfer

Answer: (c)

38. The polluted water requires Chlorine of 8 kg/day to treat 20,000 cubic metre per day. The residual after 10 minutes contact is 0.20 mg/𝑙 . The dosage will be:
(a) 0.8 mg/𝑙
(b) 0.6 mg/𝑙
(c) 0.4 mg/𝑙
(d) 0.2 mg/𝑙

Answer: (c)

39. 
(a) 1.26 ℎ
(b) 1.52 ℎ
(c) 2.52 ℎ
(d) 3.26 ℎ

Answer: (b)

40. The total hemispherical emissive power will be denoted by the symbol:

Answer: (c)