chap 10

Question 1

____________ is the amount of light incident on (striking) a surface.

Answer 1

Illuminance i

Question 2

is the amount of light leaving an object, thus relating to how bright an
object appears to the human eye.

Answer 2

 Luminance

Question 3

The luminance of a surface is equal to the reflected illuminance. (t or f)

Answer 3

t

Question 4

Luminance can be expressed in two ways:

Answer 4

o candelas per unit area
o lumens per unit area

Question 5

A luminous intensity of a surface in a given direction per unit of projected area of the
surface.

Answer 5

LUMINANCE

Question 6

It is the density of luminous flux striking a surface.

Answer 6

ILLUMINANCE

Question 7

 The appropriate units of measurement for illuminance are the ___________ and ____

Answer 7

foot-candle and lux.

Question 8

the oldest physical unit still in common use, was originally defined
as the illuminance striking a surface held one foot away from a burning
beeswax candle.

Answer 8

foot-candle,

Question 9

have ranges of illuminance from 2-3-5 to 10-15- 20
fc (20-30-50 to 100-150-200 Ix). For ambient lighting in public and working
spaces.

Answer 9

Categories A through C

Question 10

have ranges of illuminance from 20-30-50 to 100-
150-200 fc (200-300-500 to 1000-1500-2000 Ix). For common visual task
requiring more difficulty.

Answer 10

Categories D through F

Question 11

have ranges of illuminance from 200-300-500 to 1000-
1500-2000 fc (2000-3000-5000 to 10000-15,000-20,000 Ix). For prolonged,
visually demanding task.

Answer 11

Categories G through I