Light and Architectural Lighting Systems

Question 1

intensity of light
per unit area
measured by the normal luminous flux
per unit area received by it

Answer 1

Illumination or Illuminance (E)

Question 2

it is the energy radiated in the form of waves which
produces the sensation of vision to the eyes. It may be natural
light from sun or the artificial light from the means created by
human beings.

Answer 2

Light

Question 3

is that part of electromagnetic radiation spectrum
capable of exciting the retina and ultimately producing a visual
sensation..

Answer 3

Visible light

Question 4

it is the intensity of sensation resulting from
viewing light sources and backgrounds.

Answer 4

Brightness

Question 5

it is defined as the quality of visual sensation which is
associated with the spectral distribution of light.

Answer 5

Color

Question 6

Visible light can
have length between

Answer 6

4000 Å to 7500 Å.

Question 7

a strong steady dazzling light

Answer 7

Glare

Question 8

it is given by the ratio of luminous flux reflected from a
small area of a surface to the total flux incident upon it. It
depends upon the characteristics and

Answer 8

Reflection Factor or Coefficient of Reflection or Reflectance
(p)

Question 9

defined as the ratio of the total luminous flux
transmitted to it to the total flux incident on it.

Answer 9

Transmittance (T) of an Illuminated Diffuse Reflecting
Surface

Question 10

ratio of the light absorbed versus the
light striking the surface

Answer 10

Absorptance (α)

Question 11

it is the
ratio of the lumens actually received by a particular surface to
the total lumens emitted by the luminous source.

Answer 11

Coefficient of utilization or utilization factor (η)