illumination

the flow of light or light flux which is measured in lumens

(a)  

the light leaving the surface which has been illuminated the source

(a)  

the light source has a luminous intensity and is measured in candela

(a)  

the light energy radiated out per second from the body in the form of luminous light waves

(a)  

unit of luminous flux

(a)  

a point source in any particular direction is given by the luminous flux radiated out per unit solid angle in that direction. in other words, it is a solid angular flux density of a source in a specified direction.

(a)  

when light falls on a surface the level of illumination on that surface is referred to as . the unit of measurement is lux

(a)  

the unit of luminous intensity and is approximately equal to one candle power.

(a)  

the average candle power of a source is the average value of its candle power in all directions.

(a)  

if the average is taken over a hemisphere instead of a sphere then this average candle power is known as

(a)