Suppose that a network can be divided into two subnets connected by only two conductors, as shown below. Two points on these conductors are labeled a and b. The power factor seen to the right of a and b is defined as cos (ϕ) if ϕ is the angle formed by the phasor V and I. (Given the parity of the cosine, it does not matter if it is the angle by which V is advanced with relative to I or for the one that is delayed.) (Image 1)
Now consider the following circuit, in which six points have been marked. (Image 2)
a) Determine the power factor seen to the right of a3 and b3
analyze your result. Does it make physical sense? What is happening to the currents in the inductor and in the capacitor?
b) Determine the power factor seen to the right first of a2 and b2 and then of a1 and b1. Re-analyze your results.
c) Calculate the capacitance that must be connected between a1 and b1 so that the power factor seen to the right of these points is 0.95 in lag. Assume the source frequency is 60 Hz.
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