Part A Set up the circuit in Fig 1 and measure the current in R3 with the multi-meter or the current sensor. (Pick any resistors you like, measure the resistances using the multi-meter BEFORE placing them on the circuit board or use the color codes.) Then calculate the theoretical value of the current by solving the equations arising from the Kirchhoff's rules: - R, ( 7 - I, ) - R312 + R2 1, = 0 R, J 2 - R , ( 1 - ] , - 12 ) + RS ( 1 , +12 ) =0 E - R2 1, - Rs ( 1, + 1 2 ) = 0 Compare the measured current with your solution and find the percent error. Part B Set up the circuit in Figure 2. R2 is now a variable resistor (the potentiometer). Turn the knob until the current reading is ZERO. If you can't get it down to zero try using different resistor combinations. Ideally, when the current is zero the resistor values satisfy the following relationship: R 1 R Z R R S Then R, RS R, = R 4 This is the theoretical value of your (variable) resistor. Remove the cable from it and measure its resistance, without turning the knob. Find the percent error between the theoretical and measured values: ben = * 100