Block+C+Group+7

Block C Group 7

1. Question How does light intesity affect the electrical output of a Pv cell? (Matt)

2. Hypothesis If theres more light intensity shining on the Pv cell there will be a higher electrical output. (Matt)

3. Materials Mulitmeter, stopwatch, 25 watt bulb, 75 watt bulb, 100 watt bulb, light intesity meter, meter stick. (Matt)

4. Procedecure 1. Have a light holder attached to a chair. 2. Put the 25 watt bulb into the light holder. 3. Put the stool 67 centimeters under the lightbulb. 4. Put the Pv cell onto the top of the stool. 5. Put the light intesity meter on the top of the stool. 6. Turn the light on for 20 seconds. 7. Measure the light intensity and voltage. 8. Repeat with a 75 watt bulb 9. Repeat with a 100 watt bulb. (Matt)

5. Data Table-(Iftikhar)
 * Watts || Light Intensity || Volt ||
 * 25 || 18.6 || 4.27 ||
 * 75 || 66.3 || 4.82 ||
 * 100 || 88.9 || 5.17 ||

6. Graph-(iftikhar) seperate sheet of paper

7. Conclusion-(iftikhar) Our hypothesis was correct because when more light intensity shined on PV cell electrical output increased. First we tested with 25 watt bulb and results was high electrical output, with 75watt electrical output was higher than 25W, and with 100 watt buld electrical output was higher than 75W. if this is replace with real PV cell for the house, electrical output will be similar to this, for example you will get more electrical output in summer than winter because there is more light intensity in hot days.

8.Problems with Lab-(iftikhar) would have done differently Sources of error
 * Extend the time of each watt bulb from 20 secound to 1minutes to test does the longer light reflection affect the electrical output.
 * change the location of lamp in every trial ti findout does the location affect the reading of voltage.
 * hold a paper on top of PV cell to find if the reading of voltage will be same.
 * tilt the PV cell to test if it get more electric output.
 * time stop wasn't accurate because sometimes i stoped at 21 or 19.
 * unacurate reading of volts.