MEC203 Chapter 12 Definitions

Question 1

Define Spectral blackbody emissive power

Answer 1

The amount of radiation energy emitted by a blackbody at a thermodynamic temperature T per unit time, per unit surface area, and per unit wavelength about the wavelength λ

Question 2

Define Blackbody radiation function f_λ

Answer 2

The fraction of radiation emitted from a blackbody at temperature T in the wavelength band from λ=0 to λ

Question 3

Define spectral emissivity ε_λ

Answer 3

The emissivity of a surface at a specified wavelength

Question 4

Define directional emissivity ε_θ

Answer 4

The emissivity of a surface in a specified direction

Question 5

Define Irradiation

Answer 5

Radiation flux incident on a surface

Question 6

Define Specular reflection

Answer 6

The angle of reflection equals the angle of incidence of the radiation beam

Question 7

Define Diffuse reflection

Answer 7

Radiation is reflected equally in all directions