Kirchhoff's second law is like going on a hike from your car around a mountain (independent of path). When you get back to your car, your net change in potential energy is zero. No matter how you measure voltages around a circuit, when you return to your starting point the change in voltage is zero. Figure 2. Protoboard connection for the series circuit PROCEDURE Part 1 Select three adjacent resistors and connect them in SERIES with your power supply. Now measure the voltage at each node (A thru E) in your circuit. Measure the voltages at all of the nodes relative to the power supply ground. Show that the sum of the voltages ACROSS all of the components in a loop complies with Kirchhoff’s voltage law. Complete Table 1. 1. Voltages across each component and current through each resistor VEA VAB VBC VCD VDE Calculated IR1= Calculated IR2= Calculated IR3= Measured IR1= Measured IR2= Measured IR3= Power Power Power Power Power Now measure the node voltages relative to node C. For example, Vca = -Vac which says that the voltage from c to a = minus the voltage from a to c. The voltages at the nodes relative to ground will not add to zero to prove Kirchhoff’s voltage law. It is the sum of the voltages across each component in a series that add to zero NOT the sum of the node voltages. Remember, the reference node in a circuit can be anywhere you want in a real circuit.
Kirchhoff's second law is like going on a hike from your car around a mountain (independent of path). When you get back to your car, your net change in potential energy is zero. No matter how you measure voltages around a circuit, when you return to your starting point the change in voltage is zero. Figure 2. Protoboard connection for the series circuit PROCEDURE Part 1 Select three adjacent resistors and connect them in SERIES with your power supply. Now measure the voltage at each node (A thru E) in your circuit. Measure the voltages at all of the nodes relative to the power supply ground. Show that the sum of the voltages ACROSS all of the components in a loop complies with Kirchhoff’s voltage law. Complete Table 1. 1. Voltages across each component and current through each resistor VEA VAB VBC VCD VDE Calculated IR1= Calculated IR2= Calculated IR3= Measured IR1= Measured IR2= Measured IR3= Power Power Power Power Power Now measure the node voltages relative to node C. For example, Vca = -Vac which says that the voltage from c to a = minus the voltage from a to c. The voltages at the nodes relative to ground will not add to zero to prove Kirchhoff’s voltage law. It is the sum of the voltages across each component in a series that add to zero NOT the sum of the node voltages. Remember, the reference node in a circuit can be anywhere you want in a real circuit.
ECE%20231%20Laboratory%20Manual%20090112%20(word%2010).docx