Laws Of Illumination

Question 1

Lumen Method equation

Answer 1

N = E x A / MF x UF x F

Question 2

Inverse square law equation

Answer 2

E = I / D^2

Question 3

Cosine law equation

Answer 3

E = I / D^2 x cos(lux)

Question 4

What’s Candela ?

Answer 4

Candela is the rating of light intensity

Question 5

What’s flux

Answer 5

Flux is the rating of total output of light

Question 6

What’s lumen method

Answer 6

Is used to determine the number of lamps that should be installed for a given area or room to achieve a specific illuminance level

Question 7

Describe Illumination

Answer 7

The amount of light on a surface

Question 8

Light efficiency equation

Answer 8

Efficiency = light output / electrical input

Question 9

Describe indecent lamps

Answer 9

Current passes through a filament , the filament gets white hot and emits light ( tungsten filament lamps )

Question 10

Describe Discharge lamps

Answer 10

The electrons are driven through the gas vapour by the tube voltage colliding with atoms as they leave behind positively charged ion, this results in inosation to produce light. ( metal halide )

Question 11

Whats a Compact fluorescent lamp

Answer 11

These are miniature fluorescent tubes compacted into a small place. ( compact fluorescent lamp )

Question 12

What’s LED Lighting

Answer 12

Light emitting diode. Made from inorganic substances like gallium indium nitrade. The colour out put depends on the material used on the diode