H Exp – Radiation and Matter 07 – Variation of light intensity with distance from a point source of light
Aim – To investigate the relationship between the intensity of light and the distance from the light source.
Instructions
The light detector is connected to the light intensity meter and is placed 50 cm from the light source.
▪ Take a reading of the light intensity when the light detector is at a distance of 50 cm.
▪ Use the mouse to click and drag the light detector to a new position closer to the lamp. The light detector remains in the position when the mouse is released.
▪ Take a reading of the light intensity when the light detector is at this distance.
▪ Repeat these measurements for different distances between the detector and lamp.
▪ Plot a graph of light intensity against distance from the lamp.
▪ Plot a second graph of intensity against 1/(distance)2 to find the relationship between light intensity and distance from the lamp.