Monthly Archives: February 2013

Solar Cell Lab

Introduction:
The purpose of today’s lab was to explore and demonstrate energy intensity. By using a solar cell, a simple flashlight, a ruler and a few colored filters we were able to understand solar energy and the factors that affect intensity. With the help of the Labview VI and Microsoft Excel, once we had conducted the experiment we were able to understand the relationship between light intensity and the voltage output of the solar cell.

Procedure:
Once the solar cell was properly connected we were to shine the flashlight on it at four different distances. We first observed the intensity with the light directly up against the solar cell. We repeated this step shining the light 8, 15, and then 30 cm away from the solar cell. Utilizing Microsoft Excel once again to translate the data from the voltage output into readable numbers we plotted the data on a graph that compared voltage and distance. In order to better understand voltage output we performed the experiment with different colored filters to see the affect they would have on intensity. The results were similarly entered into Excel and depicted as a bar graph.

Conclusion:
From this experiment we learned the workings of solar energy and the variables that have an affect on intensity and voltage output. We measured factors including light intensity and color filtering and finally graphed the results to compare each factor’s influence on intensity on the solar cell.

I found this experiment helpful in understanding the way solar energy is generated and transferred.  By using a solar cell similar to the ones used on solar panels I was able to experience and manipulate the biggest factors of solar power. The experiment was clear concise and provided a scaled-down example of a hugely complicated energy system.

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Generator Lab – Faraday’s Law

photo 3photo 2photo 1photo 4Intro:
The purpose of this lab was to demonstrate Faraday’s Law, which states, “changing magnetic fluxes through coiled wires generate electricity.” In order to prove this we enlisted the help of a generator in the form of flashlight. Its usual battery-operated insides had been replaced by a tube containing a magnet traveling back and forth through a coil of wires. What was the source of power? A bit of kinetic energy created by shaking this “generator.” The flashlight was connected to a series of wires and then finally a computer which would translate the generated electricity into readable numbers.

Procedure:
Once completely connected and with LabView open, we were to shake the flashlight for thirty seconds, while counting the number of shakes per thirty seconds. The next step was to calculate (in Microsoft Excel) the sum of the squares of the voltages from that thirty-second round of shaking. We repeated this 3 times, shaking at different rates, collected the data from Excel and plotted it to fit a linear curve.

Results:
The linear curve plotted by our data seemed a bit drastic. We attributed this to a large difference in the sums of squares of the voltages. Our group hypothesized that this could be due to the difference in “number of shakes per thirty second interval.” Because our number of shakes were often high and varied in range our data was plotted that way. We performed one more round of shaking at a low rate and found our hypothesis to be in line with our results.

Conclusion:
So despite our high range of numbers and semi-drastic linear curve, our results accurately reflected the data and proved Faraday’s Law, which says changing magnetic fluxes, in this case shaking the flashlight containing the magnet, does indeed generate electricity.