How does light intensity decrease?

If I shine a flashlight on the wall, the light intensity in the middle will be higher than the instensity on the sides of the circle. How can I determine how the light intensity decreases? Thanks

2 Answers

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  • Anonymous
    3 years ago

    Measure it with a light meter.

  • 3 years ago

    Experimentally you would use a light-meter to measure the intensity at different positions in the beam. If you don't have one, this could be made from a light-dependent resisistor if you have a calibration curve showing the resistance as a function of intensity.

    Theoretically it would be very difficult to calculate as it depends on the type/size/shape of the bulb and any reflectors/lenses in the flashlight.

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