MATERIALS + TECHNOLOGY - Natural and Artificial Lighting

Question 1

Sun Chart

Answer 1

a graph pf the ecliptic of the sun through the sky throughout the year at particular latitude. it is a plot of the azimuth vs altitude throughout the day for a period of time between winter and summer solstices.

Question 2

Solar Altitude

Answer 2

The angle of the sun 90 degrees or less above the horizon

Question 3

Solar Azimuth

Answer 3

The angle from due north in a clockwise direction, given in degrees.

Question 4

Albedo

Answer 4

Ratio of the radiant flux reflected by a surface to the incidental flux

Question 5

Daylight factor

Answer 5

Ratio of the illuminate at a point on a given plan due to the light received directly or indirectly from a sky of assumed luminance, to the illuminance on a horizontal plane due to the unobstructed hemisphere of the sky

Question 6

Lumen

Answer 6

The SI unit of leminous flux, a measure of the total amount of visible light emitted by a source

Question 7

Luminance

Answer 7

A photo-metric measure of the luminous intensity per unit area of light traveling in a given direction

Question 8

Foot candle

Answer 8

The illuminance cast on a surface by one- candela source one foot awat

Question 9

Light pollution

Answer 9

Brightening of the night sky that inhibits the observation of the stars and planets, caused by the street lights and other man-made sources

Question 10

Lighting cost

Answer 10

1-3% of the construction cost