- Results Using Your Plots And Knowing The Difference In Potential Between The Equipotential Lines Calculate The Magnit 1 (28.55 KiB) Viewed 31 times
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- Results Using Your Plots And Knowing The Difference In Potential Between The Equipotential Lines Calculate The Magnit 3 (60.91 KiB) Viewed 31 times
- Results Using Your Plots And Knowing The Difference In Potential Between The Equipotential Lines Calculate The Magnit 4 (30.73 KiB) Viewed 31 times
- Results Using Your Plots And Knowing The Difference In Potential Between The Equipotential Lines Calculate The Magnit 5 (70.99 KiB) Viewed 31 times
- Results Using Your Plots And Knowing The Difference In Potential Between The Equipotential Lines Calculate The Magnit 6 (70.99 KiB) Viewed 31 times
Lab 2: Mapping of Electric Fields Introduction The purpose of this experiment is to examine the nature of electric fields by mapping the equipotential lines, sketching in the lines of force, and calculating the electric field. Background, Theory and Application An electric field is a region in which forces of electrical origin are exerted on any electric charges that may be present. If a force, F, acts on a charge, 4, at some particular point in the field, the electric field strength, E, at that point is defined as the force per unit charge and the magnitude is given by (1) Since E is a vector quantity, it also has direction, and we arbitrarily define the direction of an electric field as the direction of the force on a positive test charge placed at the point in the field. The English scientist Michael Faraday introduced the concept of lines of force as an aid in visualizing the magnitude and direction of an electric field. A line of force is defined as the path traversed by a free test charge as it moves from one point to another in the field. Fig.1 shows several possible paths that a test charge might take in going from the positively charged body to the negatively charged body. The relative magnitude of the field intensity is indicated by the spacing of the lines of force and the arrows indicate the direction. Electric Potential Since a free test charge would move in an electric field under the action of the forces present, work is done by the field in moving charges from one point to another. If external forces act to move a charge against the electric field, then work is done on the charge by the external force. If the charge, qo. Fig. 2, is placed at a point very far from the charge, q, where the repulsion is essentially zero, the work per unit charge to move it from this point to the point Pis called the absolute potential at P. The ratio of the work, w, to the charge qs is called the potential difference between the two end points of the path traversed. Hence we may write
1 Experimental Procedure 1. Connect the assembly as shown in Fig.3 leaving the switch open, until you are ready to operate the equipment. 2. Place the "stationary probe on the conducting sheet near the edge of the paper in the region between the electrodes. The potential at this point will serve as your reference potential in the location of a series of other points with the same potential. 3. On a sheet of a graph paper draw the electrode configuration that corresponds with the electrode configuration on the conducting sheet. As the points are located for the field mapping their positions can be plotted directly on the graph paper. 4. With the switch closed move the probe until the voltmeter shows zero deflection thus indicating that the two points located in the electric field are at the same potential. Now locate the series of other points with this same potential until you have ten points reaching across the central region of the field. Draw a smooth curve through these points. 5. Choose a new location for your reference probe, say 1 or 2 cm from the previous position and locate another series of equipotential points Continue this process until you have mapped all of the electric field region. Measure and record the potential difference between the separate equipotential lines. 6. Remember that the lines of force are everywhere perpendicular to the equipotential lines, draw in an arbitrary number of smooth uninterrupted lines to represent the lines of force, and to indicate direction place arrows on them. Consider the positive electrode as a positively charged body. This system of lines of force gives a graphical representation of the general nature of the electric field for this one configuration of electrodes 7. You will note that the lines of force are closer together in some regions than in others. It is also true for the equipotential lines? Place both probes at a point on the coordinate grid that corresponds to a point on a line of force where the spacings of the lines of force are large. Now examine the change in potential along the line of force, in both directions, as the hand probe is slowly moved away from the reference probe. Repeat this procedure for other points on the same line of force, some of which are in regions where the lines are closely spaced. What is the nature of your observation? 8. In analyzing your observations try to correlate them with the definition of absolute potential. V. at a distance from a charge and recall that the value is given by V. * Q/s. It will be helpful to also correlate your observation with the definition of electric field intensity in terms of the potential gradient, given by the relation E-- AV AS (3)
Data: Voltage on dc power supply = 4.1 Volts The ac on the power supply was set to 10 amperes. Voltameter Middle Point above (8.3) 1 point 20d point 15 point 2nd point above (xs) (8.30) below (X.3) 2.0 2.6 اره ادرا درا | دوا 3.2 3.4 Sillo (14.6) (16,6) (18,6) (19,6) (20,6) (14.8) (16,8) (18,8) (19.8) (2008) below (x3) (14,12) (16.12) (18,12) (19.12) (20.12) (14,10) (16,10) (18.10) (19.10) (2010) (14,14) (16,14) (18,14) 19.14) (2014) 3.7
Voltage on de power supply= 4.1 Volts The ac on the power supply was set to 10 amperes. Voltameter Middle Point above (x,y) above (x,y) |(x,y) 15 point 2nd point 19 point 2nd point below below (X.) 2.0 2.6 3.2. 3.4 3.7 يا يا دنيا ارابيا Olot (14,6 (16,6) (18,6) (19,6) (20,6 (14.8) (16,8) (18,8) (19,8) (20,8) (14,10) (16,10) (18,10) (19.10) (2010) (14,12) (16.12) (18,12) (19.12) (20.12) (14.14) (16,14) (18,14) (19.14) (20.14) 15.11) 115-17) TTT