Electric Fields Mapping Laboratory 1 I. Introduction & Brief Description of the Concepts The presence of an electric charge leads to the creation of electric field lines. These lines have a particular direction: for a positive charge, its electric field is away from the charge and for a negative charge the direction of E field is towards the charge. Therefore, the electric field E produced by a point charge is a vector: it has both a magnitude and a direction. The magnitude is given by E = k*Q/r, where k is a constant, Q is the charge and r is the distance from the location of the charge to the point in space where the electric field to be calculated. A field, in general, is an abstract notion since we cannot see the field lines (just like the gravitational and magnetic field). We can only "feel" it through its effect. Figure 1 shows representative electric field lines around positive and negative point charges. Figure 1. Maps of Electric Fields around Positive and Negative Point Charges One of the characteristics of E field is that its direction is perpendicular to the equipotential lines. These lines are defined as lines where the voltage is the same everywhere on the line. In fact, in three dimensions, these lines are equipotential surfaces. By measuring and drawing these equipotential line, we should be able to draw and visualize the electric field. In this lab you will investigate the electric fields around various charge configurations.II. Experimental Hocednre, Dara Taking and Preliminary Data Analysis 3) Simulation JA VA APP: (https:lfphetcoloradoedufenfsirnulationlcharges-and-elds} 1. You need to use the \"projector option\" in order to get a white background + add grid. There are three parts for this lab. Each lab Part 1': Two small circular spars (two charges 1 no and +lnc} 1. Place the two charges away from each other by 100cm. measure the voltage difference between two points. The goal is to look for the equipotential lines that connects between different points having the same voltage. In other words, the difference in voltage between any two points on the equipotential line is zero. In the online LAB, we use the virtual device: $ 33> FYI: DMM can he used to measure voltage and current (DC or AC), resistance, and capacitance. When making any measurement, there are always 2 wires to the DMM. One of the two wires always goes to the COM (common) terminal. In order to measure current, the second wire is attached to one of the two current inputs. But, in this lab, we will measure VOLTAGE; hence the second wire should be attached to the \"V0\" input (which also used to measure resistance). 3* In the center of the DMM there is a KNOB, make sure to turn the knob to 7. v, point towards the symbol V a] , this means you are making a voltage measurement in a Direct Current regime (DC). $ lax-Jinn! 3. Using the virtual device I- , place it at different points away from each other by the following distances: 20cm, 40cm, 50cm, 60cm and 80cm. Click on the pencil, an equipotential line will be drawn for you at each distance. 4. Print the page with the equipotential lines, then using a pencil and a ruler draw the lines (referred to as the electric eld lines} that are perpendicular to the equipotential lines. Part II: One small circular 5,901\" and a line 0 Redo the experiment by replacing one of the spots by a line. (make sure that the line is as straight as possible). Also make sure that the number of positive charges is the same as the number of negative charges. Part III: Two lines o Redo the experiment by replacing each of the two spots by a line. E III. Post-Lab: Final Data Analysis and Conclusion Answer the following questions: 1. Did any of your field lines cross? Should they? Why, or why not? 2. Did any of your equipotential surfaces cross? Should they? Why or why not? 3. Sketch the electric field lines and equipotential surface intersections; one expects around two equal positive point charges. 4. Make a similar sketch for two equal negative point charges. 5. What do you conclude about the distribution of the electric field lines for circular and line charge distributions