The light intensity 10 m from a point source is 1000 W/m².The intensity 100 m from the same source is: A)1000 W/m² B)100 W/m² C)10 W/m² D)1 W/m² E)0.1 W/m²

Question

Quizplus · Accepted Answer

The intensity of light decreases with the square of the distance from the source. Therefore, at a distance of 100 m, the intensity will be 1/100^2 or 0.01 times the intensity at a distance of 10 m. 0.01 x 1000 W/m^2 = 10 W/m^2. Therefore, the correct answer is C.

The Light Intensity 10 M from a Point Source Is