RADIATION

Question 1

The process of converting radiation intercepted by matter to internal thermal energy

Answer 1

Absorption

Question 2

Fraction of the incident radiation absorbed by matter. Modifiers: deirectional, hemisphirical, spectral, total

Answer 2

Absorptivity

Question 3

The ideal emitter and absorber. Modifier referring to ideal behavior. Denoted by the subscript b.

Answer 3

blackbody

Question 4

Modifier referring to the directional independence of the intensity associated with emitted, reflected, or incident radiation

Answer 4

Diffuse

Question 5

Modifier refeering to a particular direction. Denoted by the subscript theta.

Answer 5

Directional

Question 6

refers to variation with direction

Answer 6

directional distribution

Question 7

The process of radiation production by matter at a finite temperature. Modifiers: diffuse, blackbody, spectral

Answer 7

Emission

Question 8

Rate of radiant energy emitted by a surface in all directions per unit area of the surface, E(W/m2). Modifiers: spectral, total, blackbody

Answer 8

Emissive power

Question 9

Ratio of the radiation emitted by a surface to the radiation emitted by a blackbody at the same termperature . Modifiers: directional, hemispherical, spectral, total

Answer 9

Emissivity

Question 10

A surface for which the spectral absorptivity and the emissivity are independent of wavelength over the spectral regions of surface irradiation and emission.

Answer 10

Gray Surface

Question 11

Modifier referring to all directions in the space above a surface

Answer 11

Hemisphirical

Question 12

Rate of radiant energy propagation in a particular direction, per unit area normal to the ddirection, per unit solid anglle about the direction, I(W/m2 x sr). Modifier: spectral

Answer 12

Intensity

Question 13

Rate at which radiation is incident on a surface from all directions per unit are of the surface. Modifiers: spectral, total, diffuse

Answer 13

Irradiation

Question 14

Relation between emission and absorption properties for surfaces irradiated by a blackbody at the same temeperature

Answer 14

Kurchoff’s Law

Question 15

Spectral distribution of emission from a blackbody

Answer 15

Planck’s law

Question 16

Rate at which radiation leaves a surface due to emission and reflection in all directions per unit area of the surface, J(W/m2) Modifiers: spectral, total

Answer 16

Radiosity

Question 17

The process of redirection of radiation incident on a surface. Modifiers:: diffuse, specular

Answer 17

Reflection

Question 18

Fraction of the incident radiation reflected by matter. Modifiers: directional, hemispherical, spectral, total

Answer 18

Reflectivity

Question 19

Refers to a medium in which radiation absorption is a volumetric process

Answer 19

Semitransparent

Question 20

Region subtended by an element if area on the surface of a sphere with respect to the center of the sphere, w(sr)

Answer 20

Solid Angle

Question 21

Modifier referring to a single-wavelength (nonchromatic)
component

Answer 21

Spectral