KIRCHOFF'S RULES Simulation Used: Circuit Construction Kit (DC) from the PhET at the University of Colorado and select the Lab tab. Goal To confirm the validity of the Kirchoff's Rules in the analysis of DC circuits. B WW 50 Q 10 0 UOL 13 UO9 30 02 WW WWW 12 WW 6 V 12 V 6 V 12 V A D C Diagram 1 Diagram 2 Theory Diagram 1 shows the circuit for which we must determine the currents through and the voltage across the resistors. Before we analyze it, we must name the points between each circuit element, and choose the directions of the currents through each resistor (Diagram 2). The two loop and one-junction equations, BAD-C-B: VBA= +/1(109) VAD= + (6V) VDC= - (12V) V CB=+/2(509) Loop 1: /1 (109) + (6V) - (12V) + 12(509) =0 C -B -D-C: V CB = + /2(5092) VBD = +/3(3092) VDC= - (12V) Loop 2: /2(5092) + /3(3092) - (12V) =0 Junction D: /1 + 13 = 12Initial settings Select "Voltmeter" and "Ammeter" from the "Tools" menu on the right. Select "Schematic" from the "Visuals" menu on the right. Activity 1: Measure the voltage across the elements. Build the circuit shown on Diagram 1: 1. Click on a resistor and drag it into the circuit board. Repeat for two more resistors. ii. Click on the battery and drag it into the circuit board. Repeat for another battery. 1. Drag wires and connect the resistors and the batteries as shown on Diagram 1. Two elements are connected when their ends overlap. To disconnect two elements, left-click on the joint and select "split junction". iv. Left-click over each resistor and the battery and change their values to be equal to those shown on Diagram 1. Perform the experiment: Using the voltmeter, measure the voltage across each element. Write it down in a table. | w0 ] 00000 30 [ 00000 | so [ 0 Results: Is the sum of the voltage around each loop equal to zero? Big Loop BADCB: '84 Vap*Vpct Vea(V) -+ 0 Right Loop CBDC: - ] Left Loop ADBA: _ e Activity 2: Measure the current through the resistors. Additional Settings: 1. Continue with the same circuit from Activity 1. ii. Un-click "Voltmeter" from the "Tools" menu on the right. 1. Use the Ammeter to measure the currents. Perform the experiment: Record the value of the current 7, at the 10 Q resistor. Record the value of the current - at the 50 Q resistor. Record the value of the current [; at the 30 Q resistor. Results: Are the values for the currents equal to those calculated in the Theory Section? What about their directions? - Simulation Values (A) | Theoretical Values (A)