\f\f\f\fNAME: Phys 3B - E&M Capacitance Experiment 5: Finding the Dielectric Constant Dielectrics The goal of this lab is to find the dielectric constant of paper. No explicit procedure will be given as in past labs so you will need to be creative and careful in your measurements. Apparatus: Digital Multimeter, cables, aluminum foil, calipers, rulers, paper clips, one textbook Construct a parallel plate capacitor using two sheets of aluminum foil. These two sheets must always have the same area and be aligned to one another. Place the two sheets in your textbook at different pages, as seen in the figure below. area d DMM area Measurements This set up allows you to measure a few quantities. 1) The digital multimeter (DMM) will give you the value for capacitance. Turn the knob from the off position to the parallel-capacitor setting. You can identify the parallel setting by looking for the capacitance symbol (! !). 2) You can easily measure the area of the plates using a ruler. 3) You can measure the distance between the plates. Be careful in measuring this distance. It will be advantageous to measure these pages with higher precision than a ruler (Vernier calipers maybe?). Hint: Finding the thickness of one page is incredibly helpful for later calculations. 4) Do not use more than 16 pages between the plates. The smaller the distance between the plates, the more accurate the data. Calculations These quantities are related by the equation: C = A/q. You will use these equations to solve for your dielectric constant. However, using one measurement does not allow you to see the relationship nor is it helpful statistically. You will need to make multiple measurements and plot these measurements in a graph. Submit at least two graphs, showing the relationship between various quantities, and use these graphs to find the dielectric constant. If calculating the slope, do not calculate rise / run but use a trendline to find your slope.Phys 3B - E&M Capacitance Experiment 5: Finding the Dielectric Constant Dielectrics The average of your dielectric constant will be your experimental value. Spend some time researching values for the dielectric constant of paper. Compare the results of your research to your experimental value. Discuss in your conclusion. Sources of Error All labs have sources of error. I will discuss three sources of error here. Keep in mind that there are more sources of error beyond these three, though these are the most common. 1) Improper Alignment - It is critical that the center of the plates be aligned and that both plates are set to the same area as each other. Having the plates misaligned or having one plate with a larger area will introduce significant errors. 2) Air Pockets - Air in between your capacitor will decrease your experimental value for the dielectric constant. To minimize this error, apply a weight on the textbook. I strongly recommend having a group member sit on the textbook as you measure the capacitance. 3) Precision of DMM - The multimeter is capable of measuring a large range of capacitance. However, it's most accurate in the following range: 40.00 nF - 4.000 uF. Try your best to stay in this range by maximizing the area and minimizing the distance. Lab Report Because this lab does not have a procedure, you will need to create and write up your own procedure in your lab report. Be specific and clear as to what measurements you made and how you did them, stating which tools you used, what was the process, etc. Your data should include all the values measured in your procedure with units and short descriptions for any tables. Your calculations must include any sample calculations and the two graphs mentioned above. Be sure to include units and labels on your graphs as well as equations for trendlines