Teacher Answer Key: Testing the Sensitivity of a Solar Cell
Reflection and Discussion
Which color produced the greatest voltage? Why?
Answers may vary according to student result and the colors of cellophane used.
Which color produced the smallest voltage? Why?
Answers may vary according to student result and the colors of cellophane used.
Why did you use the clear cellophane?
The clear cellophane is used to act as a control. When using the colored cellophane as a variable to test the effect of different wavelengths on the amount of current produced, a clear piece of cellophane must be used to control any effect the cellophane itself might have in affecting the solar cell.
How would you answer someone who asked you what time of day would produce the most electricity from a PV cell?
The answer would have to include a discussion of cloud cover and geographical location. There may be more power produced at 5 p.m. with no cloud cover than at noon with heavy cloud cover. Similarly, if the geographical location is closer to the equator, then time of day would have less of an effect. The angle of the PV cell would also have to be considered.
How would you increase the output of a PV cell during the day, when the angle of the sun’s rays is constantly changing?
A system or design that would allow for the changing of the angle would provide optimal output.
Why do you think that more electricity from solar power could be produced in the winter in northern latitudes even though the Earth is farther away from the sun?
