Question

If a 72-candela light source is located at a distance of 3 meters from a surface, the illuminance on the surface is _______ lux.

Answer 1

Penn Foster Students: 8

Explanation:

Answer 2

The answer is 8 lux. Using the formula E= I/s^2, E stands for the illuminance on the surface that we are trying to solving, I stands for the intensity of the light from the sources it is candelas in the problem that we’re solving, and S stands for the distance from the light source to the surface it should be in meters.

E= I/s^2

E= 72/3^2

E=72/9

E= 8