Lab Report 1

Alyssia Villarreal PHYS L 202-002 Equipotentials Introduction Equipotentials on an object is where the surface of the object has the same potential on all points. In this experiment, the relationship between potential and distance was examined using three different methods. By using a point-point system, bar-bar system, and point-bar system, the electric field could be visualized around the different electrodes. The two straight electrodes had a curvature field while the bar-bar method showed a wavy field. When combined, they showed a mix of both where in the middle they repelled each other. Data analysis confirmed that as distance increases, potential decreases due to the charges repelling each other. Experimental Set-up The experiment was conducted by placing a clear tray filled with about a inch of water on top of graph paper marked with units of measurement in millimeters. Electrodes were placed in the water and using a metallic probe, the potential charges were measured and documented. The three methods evaluated were a point-point method which used the two straight electrodes, a bar-bar method which used the two bar electrodes, and a point-bar method which combined the two. Results were taken in a graph using the XY coordinates of the charges and then placed into a scatter plot. Results Point-Point Charges (in watts) 2.5 W 2.7 W 3.0 W 3.7 W 4.2 W X Y X Y X Y X Y X Y -11 -10 -10 8 -4 -11 3 9 9 7 -8 6 -11 -12 -1 1 4 -7 8 2 -14 9 -5 0 -7 16 5 -12 9 -5 -12 -12 -5 -3 -4 10 3 16 14 -15 -6 -1 -9 7 -3 -15 3 1 10 -7 This table shows five different charges using the point-point method. The needle was dragged through the water to find different areas on the graph where the X and Y coordinates were recorded. 1

Alyssia Villarreal PHYS L 202-002 Point-Bar Charges (in watts) 3.1 W 3.4 W 4.5 W 5.3 W 5.7 W X Y X Y X Y X Y X Y -11 -10 -6 -9 3 1 10 -10 11 8 -6 3 -8 8 3 -6 8 4 13 -2 -5 0 -7 -14 2 6 9 13 12 13 -14 10 -4 2 3 16 8 2 13 -1 -10 14 -11 12 1 -17 9 -13 16 -12 This table shows five different charges using the point-bar method. The needle was dragged through the water to find different areas on the graph where the X and Y coordinates were recorded. Bar-Bar Charges (in watts) 2.5 W 3.1 W 3.7 W 4.0 W 4.9 W X Y X Y X Y X Y X Y -6 -8 -5 -8 -1 10 0 -7 7 -2 -10 14 -4 -3 -2 6 1 3 8 11 -8 3 5 4 -1 -9 0 11 6 -4 -8 -11 6 10 -1 -7 1 -15 6 -13 -8 -6 5 15 -2 8 0 2 7 -5 This table shows five different charges using the bar-bar method. The needle was dragged through the water to find different areas on the graph where the X and Y coordinates were recorded. 2

Alyssia Villarreal PHYS L 202-002 If the potential is constant, then the electric field lines will be parallel to them. 5.) Why is the electric field a vector quantity while the electric potential is a scalar? The electric field has both direction and magnitude while electric potential might not necessarily have direction. 4