Electric Field and Electric Potential (B)

Connect P2 to the positive lead of Voltmeter B and connect P3 to the negative lead ofVoltmeter B. Connect P3 to the positive lead of Voltmeter A and connect P4 to the negative lead ofVoltmeter B. Note: the sensitivity level of the voltmeters should be set properly. Place P3 and P4(their tips should be also under the water surface) inside the tray and between the two rings.Ask your TA to check the circuit!2. Investigate Electric Potential-versus-DistanceSet the output voltage (V a −V b ) of the DC power supply to 12 V. Turn off Voltmeter B, and turnon Voltmeter A. Place the tip of probe P3 at point (r=1.5 in, =0). Place the tip of probe P4 at pointswith =0 and in turn with r′=1.7, 1.9, 2.1, 2.3, and 2.5 in. Read the correspondingly potentialdifference (V) between the P4 and P3 from Voltmeter C. Record them in Table 1. Calculate V/(r′−r) and record the ratio values in Table 1. (Note: 1 inch= 0.0254 m.)TABLE 1r′ (inch) Potential difference V (V) V /(r−r′) (V/m)1.71.92.12.32.53. Map the first equipotentialTurn on only Voltmeter B. Move the tip of probe P3 to point (r=1.5, =0). Read its potentialfrom Voltmeter B. Mark the point in Figure 2. Record it in Table 2.Turn off Voltmeter B. Turn on Voltmeter A, and move the tip probe P4 along the =90° lineuntil Voltmeter A reads 0 V. This means that the tips of P3 and P4 are place on the sameequipotential. Read out the y coordinate of the tip of P4 and mark the point in Figure 2. Record it inTable 2.Repeat the measurement by moving the tip of P4 respectively along the =180° and 270° linesuntil Voltmeter A reads 0 V. Read out the corresponding r coordinates of the tip of P4 and mark thecorresponding points in Figure 2. Record them in Table 2. Draw a curve through the four points.Tip of P3(r=1.5, =0)potential(V)TABLE 2r′ for r′ for=90° =180°r′ for=270°Averager & r′(r=1.7, =0)(r=1.9, =0)(r=2.1, =0)(r=2.3, =0)(r=2.5, =0)