Determine the diameters dA and dB (i) and evaluate r = ((dA)/(dB))2 (ii).

Step 1: Determine the diameters d_A and d_B (i) and evaluate r = ((d_A)/(d_B))^2 (ii). To determine the diameters d_A and d_B, a micrometer screw gauge is used to measure the thickness of each wire. Multiple readings should be taken at different points along each wire, and the average value calculated to minimize error. Once d_A and d_B are obtained, the ratio r is calculated using the formula: r = ((d_A)/(d_B))^2 Since no experimental data for diameters is provided, numerical values for d_A, d_B, and r cannot be determined here. Step 2: Experimental Procedure (iii) - (xi). Steps (iii) through (xi) describe the experimental procedure. This involves setting up the circuit for wire A as shown in Fig. 3(a), closing the key, and adjusting the rheostat to obtain various current (I_A) and corresponding voltage (V_A) readings. This process is then repeated for wire B, using the circuit in Fig. 3(b), to obtain I_B and V_B readings. Step 3: Tabulate the results (xii). The collected current and voltage readings for both wires A and B should be organized into a table. A suitable table structure is: | S/N | I_A (A) | V_A (V) | I_B (A) | V_B (V) | |-----|-----------|-----------|-----------|-----------| | 1 | I_A0 | V_A0 | I_B0 | V_B0 | | 2 | I_A1 | V_A1 | I_B1 | V_B1 | | 3 | I_A2 | V_A2 | I_B2 | V_B2 | | 4 | I_A3 | V_A3 | I_B3 | V_B3 | | 5 | I_A4 | V_A4 | I_B4 | V_B4 | | 6 | I_A5 | V_A5 | I_B5 | V_B5 | Step 4: Plot a graph of V_A vs I_A (xiii). Plot the values of V_A on the vertical (y) axis against the corresponding values of I_A on the horizontal (x) axis. Draw the best-fit straight line through the plotted points. For an ohmic conductor, this graph will be a straight line passing through the origin. Step 5: Determine the slope S_A of the graph (xiv). The slope S_A of the V_A versus I_A graph represents the resistance of wire A (R_A). To determine the slope, select two distinct points (I_A1, V_A1) and (I_A2, V_A2) on the best-fit line and calculate: S_A = R_A = ( V_A)/( I_A) = V_A2 - V_A1I_A2 - I_A1 The unit of the slope will be Ohms (). Without the graph, a numerical value for S_A cannot be provided. Step 6: Plot a graph of V_B vs I_B (xv). On the same axes used for wire A, plot the values of V_B on the vertical (y) axis against the corresponding values of I_B on the horizontal (x) axis. Draw the best-fit straight line through these points. This line represents the V-I characteristic for wire B, and its slope will give the resistance of wire B (R_B). Drop the next question. 📸