How Does Light Intensity Affect the Resistance of a Photoresistor?

Overview

Objectives/Goals This project examines how photo resistors work and examines new applications for them. It investigates the relationship between light intensity and the resistance of a photo resistor. Methods/Materials The materials needed for this experiment are: photocell, incandescent light bulb (4W, 15W, 25W, 40W, and 60W), multi meter, laptop, paper, and pencil. Our procedure starts with setting up the experiment based on the following diagram: Results By taking the line of the best fit, one can conclude that light intensity (measured in LUX) is inversely proportional to electrical resistance (KΩ). When light intensity increases the electrical resistance of the photocell decreases. We only tested light intensity values between 20 to 850 LUX. We assume that this linear relationship will continue if we expand our light intensity scale. Hence, we demonstrated that our hypothesis was correct. QED. Conclusions/Discussion We then found the LUX (light intensity) of each light bulb and graphed our data. On this graph LUX is the independent variable and the photocell#s electrical resistance is the dependent variable:

Competition history

• CSEF 2016 Electronics & Electromagnetics · Entry S0922

Resources

• CSEF project summary ↗

Related projects

Closest projects by meaning, across every fair and year in the corpus.

Browse more like this

• All Physics and Astronomy projects
• CSEF Physics and Astronomy projects
• Every CSEF 2016 project