How Does the Intensity of Light Change with Distance?

Light intensity is measured to understand whether a particular light source provides enough light for an intended application.  Light level recommendations for a wide range of applications and space types have been established by the lighting industry. This is useful to understand light intensity in order to evaluate whether or not space adequate lighting conditions. 

Voiceover

Presenter(s)(s)

Monita Giriyapura

Abstract or Description

To understand whether a particular light source provides enough light for the intended application is why light intensity is measured. The hypothesis investigated was to see if light intensity changes with increasing distance from the light source or if it decreases according to the inverse square law. In order to investigate, a light-sensitive resistor called a photoresistor and a digital multimeter was put to use. The photoresistor was moved farther away from the light source and resistance values were recorded and then converted into illuminance in lux. Graphs were created to make a comparison and towards the end, the conclusion that was drawn from the data was that light intensity did change with the increasing distance from the light bulb.