PHYS 222 Worksheet 12 – Kirchhoff's Laws - Iowa State University

3) All meters are idealized and the batteries have no appreciable internal resistance. (Book26.29)(a) With the switch open, what is the reading of the voltmeter?Using loop (1) :25100I15 75I 0I0.2286AV V V 0.2286(75) 15 2.145 Vbaba(b) With the switch closed, what is the reading of the voltmeter?When the switch is close, the middle branch becomes a straight wire (short circuit),meaning the voltage across it is zero. Since the right branch is in parallel with the middlebranch, it too has a voltage of zero:V = 0 V(c) With the switch closed, find the reading of the ammeter. What is the direction of thecurrent?Using the junction rule at junction (a) : I1 I2 I ' 0Using loop (2) :25100I 01Using loop (1) again with a different current in the right branch:25100I1575 I' 01Now there are three equations with three unknowns. Solve for each variable:I1 0.25 AI' 0.2 AI 0.05 A2