Pre-LAB 6 Preparation: Fundamentals of Circuits IV: Kirchhoff's ...

Fundamentals of Circuits IV: Kirchhoff’s Circuit Rules v 0.3Question 2.10 Using the method you gave as your prediction 2.2, calculate the equivalentresistance if R 1 , R 4 and R 5 are connected in parallel. Show your calculation. Does this valueagree with your measured value, within a few per cent?Predicted resistance of R 1 , R 4 and R 5 in parallel =ΩInvestigation 3:Kirchhoff’s Circuit RulesIn complex circuits with many components and branches, a simplified analysis in terms of seriesand parallel combinations is often impossible. Instead we can state and apply a formal set ofrules known as Kirchhoff’s laws to use in the analysis of current flow in circuits.We first need to define the terms ”junction” and ”branch”. Fig. 7 illustrates what we meanby these terms. As shown in Fig. 7(a), a junction is a point where two or more wires areconnected together. Different amounts of current can flow in each of the wires connected at thejunction. As shown in Fig. 7(b), a branch is a portion of a circuit such that all the elementsin the branch are in series. Thus the current is the same through every circuit element in thebranch.junction 1R 3++(a) V 1 R 2 V 2−−R 1junction 2branch 1R 3branch 2++(b) V 1 V 2−−R 1R 2branch 3Figure 7: Junctions and branches of a circuit, as referred to in Kirchhoff’s RulesThese rules can now be stated as follows:PHYS-204:Physics II Laboratory 10